***Useful Information For The Working Sparky***

[amberleaf]

“ Rcd's “

Fire detection circuits must be supplied independently of other circuits and not protected by an Rcd protecting multiple circuits. 560.7.1 All circuits in a bath shower room must be protected by a 30mA RCD. P166, 701.411.3.3
Where applicable an RCD notice must be fixed on or next to the CCU 514.12.2 An RCD should not be used as a main switch 314.2 If the maximum Zs values for a circuit in a TN systems cannot be met, the circuit may be protected by a 30mA RCD. 531.3.1
If the maximum Zs values for a TN systems cannot be met, the installation may be protected by an 100mA RCD and treated as a TT systems . 531.3.1 : 411.5.1 : 411.5.2 : 411.5.3
Unless specifically labelled or suitably identified, all 13A socket outlets must be protected by a 30mA Rcd. 411.3.3
In a TN systems , the part of a lighting circuit in a bath or shower room is required to be 30mA RCD protected. 411.3.3 , 701.411.3.3

Where a cable is buried in a wall or partition at a depth of less than 50mm on either side it must be sufficiently mechanically protected against penetration OR RCD protected AND installed either horizontally within 150mm of the top of the wall or vertically within 150mm of the angle formed where two walls meet or run horizontally or vertically to an accessory, luminaire or CCU 522.6.6 , 522.6.7 . This applies to a cable in a partition constructed using metallic parts other than fixings irrespective of the cable depth. 522.6.8

Surface run cables do not require RCD protection. OSG p22

A single RCD protecting a TT systems must be installed at the origin of the installation unless the part of the system between the origin and the RCD fulfils the requirements for protection by Class 11 equipment or equivalent insulation 531.4.1

All Electrical equipment must be accessible for operation , inspection & testing maintenance and repair. 132.12

Rcd Test Procedure

Many RCD test meters have a facility where tests can be carried out during the positive or negative half of the supply cycle. For tests 1 & 2 the RCD operating time to be recorded is the longer of the two measured during the half cycle tests.

DO NOT press the test button on the RCD before testing as this can temporarily reset a faulty RCD

Test 1
Adjust the current setting on the test meter to 100% of the rated trip current of the RCD and perform a test. A general purpose BS4293 RCD should operate within 200mS . A general purpose BS-61008 RCD or RCBO to BS-61009 should operate within 300ms

Test 2
An RCD provided for Basic Protection should have a rated TRIP current not exceeding 30mA If the RCD is rated at 30mA , adjust the current setting on the test meter to 150ma ( x5 ) and perform a test. The RCD must operate in a time not exceeding 40mS.
Test 3
Adjust the current setting on the test meter to 50% of the RCD trip current and perform a test. The RCD should not operate within 2 seconds
The Test Button : Finally operate the RCD by pressing its test button

 

[amberleaf]

“ Cables “ & Stuff (1) this will make it easy for you all in one ?

● A Reference Method Indicates , ( The Instillation Method )

● A Final Circuit is Wired between the , ( Distribution Board and Current Using Equipment )

● The Reading Provided when Cross Connecting the Incoming Phase and the Outgoing CPC and Vice versa on a Final Ring Circuit Test would be
( R1 + R2 )

● What’s the Function of a “ Shorting Lead “ when Conducting Continuity , ( R1 + R2 ) Tests ( “ It Completes the Live to CPC Test Loop ” )

● An Initial Check at the End of a Ring Final Circuit would Not Indicate ( Interconnections )

● The Earth Fault Loop Impedance Reading on a Ring Final Circuit is best Achieved Using an Earth Fault Loop Impedance
Tester and , ( BS -1363 Fly Lead )

● When Applying the Rule of Thumb Method , the Value of Prospective Short-Circuit Current for a 3 Phase Supply should be ,
( Twice the Single Phase Value )

● When Carrying Out a Prospective Short Circuit Fault Current Test on 3 Phase Systems the Approximate Fault Current between Phases should be
( Double the Fault Current between One Phase & Neutral )

● the Most Convenient Method of Determining the Value of the Prospective Short Circuit Current at the Origin of an Existing Installation would be ,
( Measurement )

● Method of Determining the External Loop Impedance ( Taking Reading at the Origin of the Supply )

● Earth Fault Loop Impedance Test Performed on a Ring Circuit will Record
( Resistance of Line and Protective Conductors and External Loop Impedance

● Electrical Installations Shall be Divided into Circuits to ( Reduce Unwanted Tripping of RCD )

● To Ensure the Protective Device Operates Requires a ( Low Fault Loop Impedance Path with a Resultant High Earth Fault Current Flow )

● The Effects of Creating a Ring Final Circuit would be that the Overall Resistance of the Conductors would ( Decrease )

● The Resistance in Ohms , of a Conductor ( Increases with Increase of Cable Length )

● if you Double the Length of Wire ( you will Double the Resistance of the Wire )

● if you Double the Cross-Sectional Area of a Wire you will Cut its Resistance in ( Half )

● What is the Preferred Way of Reducing Excessive Voltage Drop in a Circuit , ( Increased Cable CSA )

● the Value will Decrease as we Move Farther away from the Intake Position ( Resistance Increases with Length )

● End to End Resistance Checks would be Carried out on a ! ( Ring Final Circuit )

● To Ensure the Protective Device Operates Requires A ( Low Fault Loop Impedance Path With a Resultant High Earth Fault Current Flow )

● As a Cable Increases in Length , Unlike the Conductor Résistance which Increases with Length ,
( Insulation Résistance Decreases with Length )

Residual Current Operated Circuit Breaker ( BS-EN 61008-1
BS-EN 61008-1 : 2004 Residual Current Operated Circuit –Breaker without Integral Overcurrent Protection for Household
And Similar Use ( RCCBs )
Replaces ( BS-EN 61008-1 - 1995 )
International Relationships ( EN-61008-1: 2004 Identical , IEC-61008-1: 1996
Amended by / AMD 17447 November 2007

BS-EN 61009-1 / 1995
Electrical Accessories , Residual Current Operated Circuit Breaker with Integral Overcurent Protection for Household and
Similar Uses ( RCBOs ) General Rule CU , Regs 41.3
International Equivalent EN-61009-1 / IEC 61009-1: 1991
Replaces by BS-EN 6009-1 : 2004 ( Remains Current ) Appendix 1 p-236

2.1 (a) BS-7671 IEE Regulations Define Extra-Low-Voltage a.c ( Not Exceeding 50V , ps this one is still ongoing

531.2.9 Where , for Compliance with the Requirements of the Regulations for Fault Protection or Otherwise to Prevent Danger , Two or More RCDs are in Series , and where Discrimination in their Operation is Necessary to prevent Danger , The Characteristics of the Devices shall be such that the Intended Discrimination is Achieved ,

411.8.3 Requirements for Fault Protection where a Circuit-Breaker is Used , the Maximum Value of Earth Fault Loop Impedance (Zs) shall be Determined by the Formula in Regulation 411.4.5 , Alternatively , the Values Specified in Table 41.6 may be Used Instead of Calculation for the Nominal Voltages (Uo) and the Type and Ratings of Overcurrent Device Listed therein ,

Operation of the Overcurrent Device in Tables of , 41.3 / 41.4 ( where Circuit Lengths’ need to be Limited )

132.11 Prevention of Electrical Equipment , the Electrical Installation shall be Arranged in such a way that No Mutual Detrimental Influence will Occur between Electrical Installation and Non- Electrical Installation Electrical Installation ( Condensation , Smoke , Heat , Thermal Installation , Electromagnetic Interference , / sec , 515 – 528 ,

Telecommunications Systems-BS 6701 ( Operates 50v d.c / Ringing Voltage in Excess off 80v a.c )

Mac I’ve got Problems with down Loading onto the Forum
My Sizing going to pot
An having to down load one at a time , and dropping it to size 8
PS can you see Dan ,

Sorry Caps I have to stop Down Loading stuff , Amberleaf

 

[amberleaf]

Outgoing Circuits

An Rcd with a Residual Operating Current Not Exceeding 30mA is Recognised Device for Providing Additional
Protection in the Event of ,
1 , Electrical Fault ,
2 , Failure of Basic Protection ,
3 , Carelessness by the User or Operator ,
Such RCDs should Not be Used as Sole Means of Protection and do Not avoid the need to Apply one or more of the Protective Measures ,
Detail in the Regulations ,
Under the New Regulations , an Installation is Required to Incorporate One or More RCDs Depending on the Circumstances ,

The Regulations Affecting RCD Protection

411.3.3
Additional Protection by Means of a 30mA RCD is to be Provided for all Socket-Outlets with a Rated Current Not
Exceeding 20A for Use by Ordinary Persons ,
The Only Exceptions Allowed are for Socket-Outlets for Use Under the Supervision of “ Skilled “ or Instructed Persons e.g.
Some Commercial / Industrial , Locations or a Specifically Labelled Socket Provided for Connection of a Particular
Item of Equipment , Such as Freezer ,

701.411.3.3
In Specific Locations such as those Containing a Bath or Shower there is Now a Requirement to Provide RCD Protection
On all Circuits , Including Lighting and Shower Circuits ,

314.1 & 2 / 531.2.4
Every Installation should be Provided into Circuits as Necessary to Avoid and Minimise Inconvenience in the Event of a Fault ,
Designers are Required to Reduce the Possibility of Unwanted RCD Tripping due to Excessive Protective Conductor Currents
But Not due to an Earth Fault ,
Separate Circuits’ may be Required for parts of the Installation which need to be Separately Controlled in such a way
That they are Not Affected by the Failure of other Circuits ,
The Appropriate Subdivision should take Account of any Danger arising from the Failure of a Single Circuit ,
RCD Trip Causing the Disconnection of an Important Lighting Circuit ,

522.6.7
Much Greater Use of RCD is Required to Protect Wiring Concealed in Walls or Partitions , even where this is Installed
In Previously Defined Safe Zones ,
This Effectively means that all Concealed Wiring at a Depth of Less than 50mm from the Surface now Requires
Protection by 30mA RCD Unless Provided with Earthed Mechanical Protection ,

RCBO BS-EN 61009-1 is a Combination of an MCB & RCD This Enables Both Overcurrent Protection & Earth Fault Current protection and detection
Protection by a Single Unit

IP Rating , RCBO Front Plate IPX4 / Screw IPX2 ←

These may be Operated with our without Overcurrent Protection ( RCBOs )
With Single Pole RCBOs , even when they have Tripped , the Neural Wire is still Not Interrupted ←←
The RCBO will Trip and Cut off Power ,

RCCBs BS-EN 61008-1
Voltage Dependent RCCBs are Reliant on the Line Voltage to Trip the Switch through an Electronic Control Device ,
RCCBs
Provides Protection Against Earth Faults Occurring in Equipment and Reduces the Effects of Electrical Shock ,
RCCBs Measures the Current Flowing in the Line & Neutral Cables
And if there is an Imbalance , that is Current Flowing to Earth above the RCCB will Trip and cut off the Supply

Selection of conductors’ for Current Carrying Capacity & Voltage Drop
Are the Cables the Correct size for the Current which they have to Carry and is the Voltage Drop
In the Circuit below the Permitted Value ,
Regulations 523 / 524 / & 525 – part 4 ,

Erection Methods
Has the Installation been Erected to Comply with BS07671 Part 5

Regulations table 4A1 , appendix 4 & 522 ,
Correct Type of Installation to Suit Environment , Standard of Workmanship and Suitability of Fixings ,

Routing of Cables and in Prescribed Zones or within Mechanical Protection
Regulations 522.6 BS7671 & 7.3 OSG , Intended for use when Completing an Electrical Installation Certificate ,
Only Limited Inspection would be Possible during a Periodic Inspection Report ,

Connection of Conductors
Regulations 526 . Check for Tightness & Correct use of Terminations at a Random Selection of Accessories and all Distribution Boards ,

Presence of Fire Barriers , Suitable Seals & Protection against Thermal Effects
Reg , chapter 42 & section 527 ,
This is to Ensure that Structural Fire Barriers are not broken During Installation ,
Fire Barriers are Present in Trunking & Ducting where Required , and Intumescent hoods on Lighting where
Installed in Fire Rated Ceilings , Heat from Installed Equipment must Not be Likely to Cause a Fire ,
Particularly , Check that backless Accessories such as wall Lights and Electrical Enclosures are Installed
On Surfaces Suitable for Surface Temperatures & Radiated heat of Equipment

General ,
Presence and Correct Location of Appropriate Devices for Isolation and Switching ,
Reg , chapter 53 sec 7 Isolators Identified where not Obvious ,
Local and Under the Control of user or , if Remote , they must be Lockable and Identified Isolation of Fans with Timers Controls
In Bathrooms ( table 53.2 p-117
For Correct Selection of Devices ,

“ Periodic Inspection Report “

This Document is Used to Record the Condition of the Installation In Particular , is it Safe to Use ,
It is , however , Important that the Person Carrying Out the Inspection and Test is Competent ,

This Report must Also include a Schedule of Test Results and a Schedule of Inspection ,

A Periodic Inspection Report is Carried Out for Many Reasons ,
(i) The Due Date ,
(ii) Clients / Customers Request ,
(iii) Change of Ownership ,
(iiii) Change of use , Insurance Purposes
To Inspect the Condition of the Existing Installation , Prior to Carrying out any Alterations or Additions ,

The Frequency of the Periodic Inspection and Test is Dependent on the Type of Installation ,
The Environment and the Type of Use , BS 7671 Wiring Regulations refer to this as the ,
( Construction , Utilization and Environment )
Appendix 5 BS 7671 ,

Guidance Note 3
For the Inspecting & Testing of Electrical Installations has a Table of Recommended Frequencies for Carrying Out
Periodic Inspection & Tests / The Period Depends on the Type of Installation ,
The Recommended Frequencies , it is the Responsibility of the Person Carrying Out the Periodic Inspection & Tests
To Decide on the Period between Tests ,
This Decision should be Based on the Inspectors Experience ,
What the Installation is Used for ,
How Often it is Used , The Type of Environment that Surrounds the Installation ,
Many Others should be Taken into Account when Setting the Next Test Date ,

It is Important to Remember that the Date of the First Inspection & Test is set by the Person Responsible for the Installation Design , ( Change of Use or Ownership )

Careful Consideration must be Given to the Installation before the Date of the Next Periodic Inspection & Test is Set , ←←←←
It is Very Important that the Extent and Limitations of the Inspection and Test is Agreed with the Person Ordering the Work
Before Commencing Work ,

Before the Extent and Limitations can be Agreed , Discussion between all Parties involved must take Place , ←←←←
The Client will know why they want the Inspection Carried Out and the Person who is Carrying Out the Inspection and Test should have the Technical Knowledge and Experience to give the Correct Guidance ,

Test Results , Electrical Installation , / Periodic Inspection Reports
Fuse , Charts etc must be Made Available to the Person Carrying out the Inspection & Test , ←←←

If these are Not Available , then a Survey of the Installation must be Carried Out to Ensure that the Installation is Safe
To Test and to Prepare the Required Paperwork , such as Fuse Charts ,

Whist Carrying Out a Periodic Inspection & Test it is Not a Requirement to take the Installation Apart ,
This Should be Carried Out with the Minimum of Intrusion ,
Disconnection should Only be Carried Out when it is Impossible to Carry Out the Required Test
In any Other way , if an Insulation Résistance Test is Required on a Lighting Circuit with Fluorescent Lighting Connected to it ,

Would be to Open the Switch Supplying the Fluorescent Fitting before Testing between the Live Conductors ,
And Close the Switch when Conducting the Test between Live Conductors and Earth ,
It is Not a Requirement to Disconnect the Fitting
( Insulation Résistance Testing , Chapter 4 )

 

[amberleaf]

Supply , Characteristics , Earthing & Bonding Arrangement
Supply , Characteristics , Nominal Voltage of the Supply
System Type TT . TN-S or TN-C-S ,

Nominal Frequency , Normally 50Hz , 110.1 ( xv )

● Prospective Fault Current ,
The Highest Current that could Flow within the Installation between Live Conductors , or Live Conductors & Earth ,
This should be Measured or Obtained by Enquiry , if Measured , Remember that on a ( 3 ) Phase System
The Value between Phase & Neutral must be Doubled ←←←

● External Earth Loop Impedance , ( Ze ) this is the External Earth Fault Loop Impedance Measured between the
Phase & Earthing Conductor for the Installation ,

Characteristics of the Supply Protective Device ,
● BS- Type , can Normally be Found Printed on the Service Head ,
● Nominal Current Rating , can Normally be found Printed on the Service Head ,
● Short-Circuit-Capacity , this will Depend on the Type , If in Doubt Reference / T- 7.4 OSG ,
● Main Switch or Circuit-Breaker , Type is Normally printed on it , ( Appendix 2 – BS-7671 if Required )
● Number of Poles , Does the Switch Break all Live Conductors when Opened ( or is it Single-Pole Only )
● Supply Conductor Material & Size , ( Refers to Meter Tails )
● Voltage Rating , ( this will Usually be Printed on Device )
● Current Rating , ( this will Usually be Printed on Device )
● RCD Operating Current , ( I∆n ) this is the Trip Rating of the RCD & should Only be Recorded if
The RCD is Used as a Main Switch )
● RCD Operating Time at ( I∆n ) Only to be Recorded if the RCD is Used as Main Switch ,
Means of Earthing ,
Distributors , Facility or Earth / Electrode ,
Type , if Earth / Electrode ,
Electrode Résistance , Usually Measured as ( Ze )
Location , where is the Earth / Electrode ,

Method of Measured ,
Has an Earth Fault Loop Tester or an Earth / Electrode Tester been Used to Carry Out the Test ,
To do this Test Correctly , the Earthing Conductor shall be Disconnected to Avoid the Introduction of Parallel Paths ,
This will of Course Require Isolation of the Installation ,
In some Instance this May Not be Practical or Possible , ( for Reasons )

If Isolation is Not Possible , the Measurement should still be Carried Out to Prove that the Installation has an Earth ,
The Measurement Value of ( Ze ) should be Equal to or Less than any Value for ( Ze ) Documented on Previous
Test Certificates ,
If the Measurement is Higher than those Recorded before , then Further Investigation will be Recorded ,

The Higher Measurement could be Caused by Corrosion ,
Loose Connection / or Damage ,

If the Means of Earthing is by an Earth Electrode ,
The Soil Conditions may have Changed , this would be Considered Normal Providing that the Measured Value
Is Less than ( 200Ω ) 411.5.3 Note 2 ,
And the systems is Protected by a Residual Current Device ,

Main Protective Conductors

Earthing Conductor
Conductor Material , What is it Made of ,
Unless Special Precautions are Taken in Accordance / BS-7671 ( this should be Cooper )

Conductor Cross-Sectional Area
This must Comply with Regulation Sec / 543 ,
If the System is PEM then Regulations 544.1
In most Domestic Installation’s this will Require ( 16mm2 ) further Information / 4.1 OSG ,

Continuity Check
This Requires a tick Only and is Usually a Visual Check ( Provided that the Conductor is Sound )

Main Equipotential Bonding Conductors ↔ ( Main Protective Bonding Conductor ) Regs p-32
Conductor Material
What is made of ,
Unless Special Precautions are Taken in Accordance / BS-7671 ( this should be Cooper )

Conductor Cross-Sectional Area
Must Comply with Regulations 544.
In Most Domestic Installations the Required Size is ( 10mm2 )
Information Available ( T – 10A / OSG )

Bonding of Extraneous Conductive Parts ,
All Services , Structural Steel , Lighting Conductors’ & Central Heating Systems should be Equipotential Bonded ↔ ( Main Protective Bonding Conductor ) Regs p-32
Regulations 411.3.1.2 ( Chap 4 - OSG
Normally a Tick Required ,

Sorry Chaps am going to Spec Savers ( PME , Protective Multiple Earthing

Correct Selection of Protective Devices

When Carrying Out an Inspection & Test on any Electrical Installation it is Important to Ensure that the Correct Size
And Type of Device has be Selective and Installed
Selection of Protective Devices and the Type of Circuits that they are Protecting ,

Protective Devices are Installed to Protect the Cable of the Circuit from Damage
This could be Caused by Overload / Overcurrent & Fault Current ,
( Overcurrent Occurring in a Circuit which is Electrically Sound ,
( Overcurrent is a Current Flow in a Cable which is Greater than the Rated Current-Carrying-Capacity of the Cables )
( Fault Current is a Current which is Flowing in a Circuit due to a Fault )

Will the Device be able to Safely Interrupt the Prospective Fault Current which could flow in the Event of a Fault
OSG. 7.4 or the Manufacturers Literature will Provide Information on the Rated Short-Circuit-Capacity of Protective Devices ,

Selection of Electrical Equipment ( Domestic Electricians 2392-10 )
133.1.1
Every item of Equipment shall Comply with the Appropriate British Standard ,
In its Absence of an Appropriate British Standard , Reference shall be Made to the Appropriate IEC Standard
Or the Appropriate National Standard of Another Country ,
133.1.2
Where there are No Applicable Standards , the Item of Equipment Concerned shall be Selected by Special Agreement between the Person Specifying the Installation and the Installer ,
133.1.3
Where Equipment to be Used is Not in Accordance with Regulation 133.1.1 or is Used Outside the Scope of its Standard ,
The Designer or Other Person Responsible for Specifying the Installation shall Confirm that the
Equipment Provides at Least the Same Degree of Safety as that Afforded by Compliance with the Regulations ,

Appendix 2 of BS-7671 Covers Statutory Regulations

Testing

To Ensure No Danger to Persons & Livestock and that No Danger Occurs to Property ,
To Compare the Results with the Design Criteria
Take a View on the Condition of the Installation and Advise on Any Remedial Works Required ,
In the Event of a Dangerous Situation ,
To Make an Immediate Recommendation to the Client to Isolate the Defective Parts ,

To Ensure the Fault is Repaired and Retest Any Parts of The Installation which Test Results May have been Affected by the Fault ,

A Circuit Breaker is Really two Devices in One Unit ,
The Overload part of the Device is a Thermal Bi-Metal Strip ,
Which heats up when a Current of a Higher Value than the Nominal Current Rating ( In ) of the Device Passes through it ,

Also Incorporated within the Device is a Magnetic Trip ,
Which Operates and Causes the Device to Trip when a Fault Current Flows through it
For the Device to Operate Correctly it must Operate within 0.1 seconds
The Current which has to flow to Operate the Device in the Required time has the Symbol ( Ia )

B Type MCBs
Should be Used on Circuits having Only Resistive Loads ,
C Type MCBs
Used for Inductive Loads such as Fluorescent Lighting , Small Electric Motors & other Circuits Where Surges could Occur ,
D Type MCBs
Used on Circuits Supplying Large Transformers or any Circuits where High Inrush Currents could Occur

Adequacy of Access to Switchgear and Other Equipment
Regulations 412.2.2.3 / 513.1 / 526. 3 / 537 / 543 / 559.10.3.1 (iii) OSG, 8.4
Doors of Enclosures must be Removable or able to be fully Opened ,
Access to Equipment should not be Obstructed ,
Cooker control switches within 2 meters of cooker & hob , app 8 , 8.4 OSG

Connection of Single Pole Devices for Protection and Switching in Line Only ,
Regulations 530.3.3 / 612.6
Switches in Phase and not Neutral Conductors, Generally Carried out when Continuity of CPC Tested along with a Visual Check ,

Correct Connection of Accessories & Equipment
Regulations 52 , section 6 Correct and Neat Connection ,
Look for Excessive Exposed Conductors , Cores of Cables not cut out where Terminal full ,
For Connection of fine wire Cables 526.8

Selection of Equipment & Protective Measures Appropriate to External Influences
Appendix 5 Regulations 512.2 chapter 52 sec 2
Check for the Suitability of a Wiring Systems for the Environment and Type of use to which it is being put
For Outdoor Lighting Regulations 559.10.4. / 559.10.5.1

Selection of Appropriate Functional Switching Devices
Regulations 537.5.2 table 53.2 Correct Operation of Switches / Isolators , throughout Installation

4 Earths / in Domestic’s , 16mm2 , 10mm2 , Presence of Supplementary bonding , CPC in Cables ,

“ At the Consumer Unit “
Before you Start this must be Isolated ,
The Electricity at Work Regulations 1989 States that it is an Offence to Work Live
Once you Remove a Cover you will be Working Live if you do Not Isolate it First ,
Having Carried Out Safe Isolation Procedure , Remove the Cover of the Consumer Unit

Part P Domestic Electrical Installation Certificate
An Electrical Installation Certificate is Required for ,
● A New Installation ,
● When New Circuits are Installed ,
● When a Single Circuit is Installed ,
● The Changing of a Consumers’ Unit ,
● When a Circuit is Altered and the Alteration Requires the Changing of the Protective Device ,

 

[amberleaf]

Domestic Electricians’
510.2 Every Item of Equipment shall be Selected and Erected so as to Allow Compliance with the Regulations Stated
In this Chapter and Relevant Regulations in Other Parts of BS-7671 and shall take Account of Manufacturers Instructions ,
511 Compliance with Standards
511.1 Every Item of Equipment Shall Comply with the Relevant Requirements of the Applicable British Standard
Or Harmonized Standard , Appropriate to the Intended Use of the Equipment ,
The Edition of the Standard shall be the Current Edition , with those Amendments Pertaining at a Date to be Agreed by
The Parties to the Contract Concerned ( App 1 )

511.1 Alternatively , if Equipment Complying with a Foreign National Standard based on an IEC Standard is to be Used
The Designer or Other Person Responsible for Specifying the Installation shall Verify that any Differences between that
Standard and the Corresponding British Standard or Harmonized Standard , will Not Result in a Lesser Degree of Safety than that Afforded by Compliance with the British Standard

511.2 Where Equipment to be Used is Not Covered by a British Standard Or Harmonized Standard , or is Used Outside the Scope
Of its Standard , the Designer or Other Person Responsible for Specifying the Installation shall Confirm that the Equipment
Provide the Same Degree of Safety as that Afforded by Compliance with the Regulations ( British Standard )
( Selection of Electrical Equipment ( 133.1.1 / 133.1.2 / 133.1.3 )

133.2 Characteristics ,
Every Item Electrical Equipment Selected shall have Suitable Characteristics Appreciate to Values and Conditions on
Which the Design of the Electrical Installation , @

Domestic Electrical
( Zs ) is the Earth Fault Loop Impedance ( Zs = Ze + R1 + R2 ) ( Zs ) is the Measurement of the Whole Fault Path R1 + R2 ) Measurement of the Circuit of Installation then ( Zs ) then has to be Low Enough to Allow Current to Flow in Order for the Protective Device to Operate New Installation , ( Values off 80% OSG T-2D ( Electrical Installation Certificate Regs – p-334 ) 1st ← ← Maximum ( Zs ) ( Values off 100% Regs – p-41.3 ( Ze ) PFC ↔ Test ( 230 ÷ 0.04 = 5750Ω , Calculation ( 6kA ) PSCC Test Across Live / Neutral , 434.5.1 PFC is Between Live / Earth ( you have Measured PFC ) PFC is the Highest of the Two Readings ( Noted on Test Cert , PSCC Prospective Short-Circuit Current ( L / N PFC Prospective Fault Current ( L / E ( Zs )

 

[amberleaf]

Sorry Chaps Jason going to have My Cuts for Carters , ( Jason will be on Prozac )
“ Documents “ ● Electricity at Work Regulations 1989 - Statutory ● IEE Guidance Note 3 – Inspection & Testing – Non- Statutory ● BS-7671 Requirements for Electrical Installations – Non- Statutory ● IEE Onsite Guide - Non-Statutory ● HSE Guidance Note GS38 - Statutory
● Next Inspection on Domestic Premises = Maximum - Ten Years , ● The age of the Installation , Change of use, Request of Insurers, Change of Ownership, Following Damage, etc,
“ New Cooker Circuit “ ● Certification / Documentation , ● Electrical Installation Certificate ● Schedule of Inspections ● Schedule of Test Results A New Circuit has been Installed back to the Origin ( Cooker ). This Requires an Electrical Installation Certificate. On replacing the Consumer Unit, you are changing the Protective devices and need to Confirm that Existing Circuits are Adequately Protected and Conform to BS-7671 ,
“ Test schedule “ ● Schedule of Inspections , ● Test Instrument Details ● Make and Model ● Serial Number ● Type of Supply / Earthing Arrangements , Regs , p-32 ● External Earth Loop Impedance – ( Zs ) ● Prospective Fault Current ( PFC ) 612.11
● Routing of cables in prescribed zones ● Selection of conductors for current carrying capacity ● Erection methods ● Presence and Correct Location of Appropriate Device for Isolation and Switching… Etc , ● Practical problems , ( Circuit Tails not Long Enough )
“ Test sequence “ Cooker Circuit “ Tests “ GN-3 ● (1) Continuity of Protective Conductors 612.2.1 (1) Full sequence is given in Regulation 612.2.1.
● Insulation Resistance ● Polarity (usually in conjunction with (1) 612.6 ( Dead Test )
GN-3 ● Earth Fault Loop Impedance , ( Live Test ) 612.9 ● Operation of Switch / Isolator , ( Functional Testing ) 612.13.2
“ Instruments “ ● Low-reading ohmmeter – Ohms , ● Insulation Resistance Tester – M W , ● Loop Impedance Tester – Ohms ,
“ Inspection & Test of Industrial Unit “ ● Periodic Inspection Report ● ( Referring to question ) Extent and Limitations of the Inspection ● The ‘Person Ordering the Work’ ( the Client ) ↔ Originals Retained by Client (‘Person Ordering the Work’ )
“ Minor Works Cert “ ● System Earthing Arrangements ●Type and Rating of Protective Device for Modified Circuit
“ Units “ ● mA (and ms) milli-A mps ( and milli-seconds ) “ Sequence of tests “ GN-3 ● Continuity of protective conductors ● Continuity of ring final circuit conductors ● Insulation Resistance ● Polarity

 

[amberleaf]

“ Earthing / Bonding Terminology “ Regs , p-32 ● Main Earthing Conductor ● Circuit Protective Conductor ● Supplementary Protective Bonding Conductors ( where required )

“ IP Codes “ ● IP4X top Distribution Board , 416.2.2 ● IP2X or IPXXB side Distribution Board ● Domestic-Switchgear , by use of tool or key , ( 416.2.4 )

“ CPC Continuity Test “ ● Low Reading Ohmmeter / W - Ohms , ● Either Zero the meter with leads connected to each other, or record the resistance of the leads and deduct it from measurements. ● Last point (or highest reading) is the value of (R1 + R2) for the circuit

“ Ring Circuit Continuity “ ● Verify continuity of CPC. Confirm a Ring exists without ↔ Interconnections ↔ obtain values of R1 and R2 with which to compare Directly measure ( R1 + R2 )

“ Insulation Resistance “ MW - Mega-Ohms , “ Isolate Installation from Supply “ ≈ ● Remove all lamps ←← ● Disconnect all Sensitive Equipment – Dimmers , Neon’s , Fluorescents etc , ( a must ) ● Close all Switches ↔ ● Check test leads ↔ ● Set Meter tester to 500V d.c. ● Test between Live / Neutral - Live / CPC and Neutral / CPC , ≈ ● Lowest Reading Must be Greater than 2 MW. If a Lower Reading is Obtained then Circuits must be Tested Individually ,
“ Insulation Resistance of SELV and PELV Circuit “ 612.3.2 ● 250V d.c. ● ≥ 0.5 MW ● 500V d.c. ● ≥ 0.1 MW “ Insulation Resistance Values “ ● 0.00 MW = Dead Short , ● 0.08 MW = Low Insulation Resistance Fault , ● ≥ 200 MW = Healthy Circuit ,
“ Loop Impedance “
● To Determine that an Earth Fault path Exists and is low enough to allow Sufficient Current to Flow in the Event of a Fault to Operate the Protective Device within the Prescribed Times , ● Increase the size of CPC to bring it up to 17th Edition if needed ( The method is to use an RCD 30mA ) ● The Highest Zs Value is Recorded. ● The Earth Fault Loop Impedance must be low enough to comply with the Requirements of the Protective Devices in the New CCU. Also it is essential to Verify that an Earth Fault Path Exists before a Circuit is Connected to the New CCU ,

“ 30mA RCD “ mA (and ms) milli-A mps ( and milli-seconds ) ● For Operation of Portable Equipment Outside the Main Protective Bonding Conductor Zone , ● To meet Disconnection Times if Zs is too high , ● For fixed Equipment in Bathrooms , ● For all Sockets on a TT system ,

“ 500mA RCD Tests “ ● Apply 50% current (250mA) – RCD should not trip on either half-cycle , ● Apply 500mA (rated current) – RCD should operate within 300ms , ● Test ‘T’ button to verify Electro-Mechanical Operation. ( Functional Test ) 612.13

↔↔ Insulation Resistance Tester – M/Ohms ↔↔ the Ω Sign didn’t get through Sorry ( M W ) should be Ohms ←

“ Prospective Fault Current at origin “ ● Maximum Zs values given in Schedule of Test Results , ● In this case the Zs values must Be Calculated and this fact Noted on the Test Schedule ● The Type and Rating of the Distributors’ fusible cut-out or protective device , ● Basic Information Required , Nature of Supplies 313.1 / O.S.G p-13 , ● You’ll Need to Write this in your Schedule of Test Results , when your Finished the Testing on the Board(s)

 

[amberleaf]

Electrical Installation Certificate

The Electrical Installation Certificate is to be Used Only for the Initial Certificate of a New Installation or for Alteration or Addition
To an Existing Installation where New Circuits have be Introduced ,

It is Not to be Used for Periodic Inspection for Which a Periodic Inspection Report Form should be Used ,
For Alteration or Addition which Does Not Extend to the Introduction of New Circuits ,
( a Minor Electrical Installation Works Certificate may be Used )

The Original Certificate is to be Given to the Person Ordering the Work ( 632.3 ) p-163
A Duplicate should be Retained by the Contractor ,

Electrical Installation Certificate
(i) the Electrical Installation Certificate Required by Part 7 shall be Made Out and Signed or Otherwise Authenticated by a
Competent Person or Persons in Respect of the Design ,

(ii) the Minor Works Certificate Required by Part 7 shall be Made Out and Signed or Otherwise Authenticated by a
Competent Person or Person in Respect of the Inspection & Testing of an Installation

(iii) the Periodic Inspection Report Required by Part 7 Out and Signed or Otherwise Authenticated by a Competent Person
In Respect of the Inspection & Testing of an Installation ,

(iv) Competent Persons will , as Appropriate to their Function Under (i) – (ii) – (iii) Above ,
Have Sound Knowledge and Experience Relevant to the Nature of the Work Undertaken and to the Technical Standards
Set Down in this British Standards ,
Be Fully Versed in the Inspection and Testing Procedures Contained in this Standard and Employ Adequate Equipment ,

(v) Electrical Installation Certificate will Indicate the Responsibility for Design ,
Construction , Inspection & Testing , whether in Relation to New Work or Further Work on an Existing Installation ,


Where Design , Construction and Inspection & Testing , is the Responsible of One Person a Certificate with s Single Signature
Declaration in the Form Shown below may Replace the Multiple Signatures Section of Mode Form

“ FOR DESIGN , CONSTRUCTION , INSPECTION & TESTING “

(iv) a Minor Works Certificate will Indicate the Responsibility for Design , Construction , Inspection & Testing
Of the Work Described in Part 4 of the Certificate

(vii) a Periodic Inspection Report will Indicate the Responsibility for the Inspection & Testing of an
Installation within the Extent & Limitations Specified on the Report

(vii) a Schedule of Inspections and a Schedule of Test Results as Required by Part 7 shall be Issued with the Associated
Electrical Installation Certificate or Periodic Inspection Report

(ix) when Making Out and Signing a Form on Behalf of a Company or Other Business Entity ,
Individuals shall State for Whom they are Acting ,

(x) Additional Forms may be Required as Clarification , if needed by No-Technical Person , or in Expansion , for Larger
Or More Complex Installation ,

(xi) the IEE Guidance Note 3 Provides Further Information on Inspection & Testing on Completion and for Periodic Inspections ,

2392-10
Options for Showing Electrical Installation Competence

The Following is Provided as a Guide to Different ways in which in any Electrical Work Undertaking can be Certified ,

(i) if an Approved Certifier of Construction has Carried Out Electrical Work then that Contractor will Provide the Appropriate
Certificate , Duly Completed , for the Council to Verify OR

(ii) if the Electrical Contractor or Electrician is Not an Approved Certifier of Construction then the Appropriate Certificate
Taken from BS-7671 2008 should be Submitted , Duly completed , Together with Evidence of Competency ( i.e. Valid ↔
JIB Card or having Current Membership of an Accredited Registration Scheme Operated by a Recognised Professional
Body e.g. NICEIC or Select or Equivalent Body OR

(iii) if the Electrical Work was Carried Out by a Qualified Electrician , it may be the Case that you will Need to have the
Installation Checked by a Qualified Electrician and the Appropriate Certificate in Accordance Submitted ,
With Evidence of Competency ( i.e. Valid JIB Card / or having Current Membership of an Accredited Registration
Scheme Operated by a Recognised Professional Body e.g. NICEIC or Select OR Equivalent Body ,

Testing Class II Equipment

The test includes:
• physical examination
• insulation test
• flash test (optional)
The first test conducted must be the detailed physical examination. Any faults found should be corrected and defective items replaced.
The first electrical test performed will be the insulation resistance test. If the appliance is double-insulated then the insulation test is carried out between the combined live and neutral pins on the plug and a probe that is applied to the outside of the appliance case. Make sure that the appliance under test is turned on. The resistance reading should be at least 2 M Ohms. If the resistance reading is less than the value you must investigate why. Do not use the appliance until the fault has been cleared.
Testing Class III Equipment
Class III equipment is designed to be supplied by a reduced voltage which is normally 110V. Portable Appliance Testers are usually rated to operate at 240V and manufacturers usually provide each model in two versions to be able to test class III apparatus separately.
APPENDIX 1
BS1363 - 13A plugs, switched and unswitched socket outlets and boxes.
BS2754 - Construction of electrical equipment for protection against electric shock.
BS2769 - Hand-held electric motor-operated tools.
BS3456 - Safety of household and similar electrical appliances.
BS3535 - Specification for safety isolating transformers for industrial and domestic purposes.
BS4343 - Industrial plugs, socket outlets and couplers for AC and DC supplies.
BS4533 - Luminaries’.
BS4743 - Safety requirements for electronic measuring apparatus. (IEC348).
BS5458 - Safety requirements for indicating and recording electrical measuring and their accessories.
BS5850 - Safety of electrically energised office machines. (IEC380).
BS6204 - Safety of data processing equipment. (IEC435). BS6500 - Insulated flexible cords.
BS7002 - Safety of I.T. equipment including business machines. (IEC950).
Note: The IEC reference is the International Electrotechnical Commission "parent" standard. For Appendix 2 & 3 please consult the "Electrical Safety Testing" booklet.

 

[amberleaf]

Testing Class I Equipment

The tests include:
• physical examination
• earth bond test - essential
• insulation test - essential
• flash test - optional
• operation test - optional
• power consumption test - optional
A detailed visual inspection should be performed first and any faults corrected. Over 75% of all equipment defects can be found at this first stage. Hazards such as loose cable grips, plugs incorrectly fitted, unsafe cable joints, damaged cable, wrong value fuses or illicit fuses should all be discovered and corrected at this physical inspection stage before electrical tests are commenced.
Before performing the electrical tests, it is important to establish whether the appliance is a light current type. Assume the appliance to be light current if it has a 3 or 5A fuse fitted, if it has a power rating less than 1kW or if the appliance cable is thinner than the normal mains lead. If these criteria apply then the appliance tester will be operated in a different manner. The manufacturers instruction booklet should be referred to.
The first essential test for class 1 appliances is the earth bond test. This test is intended to ensure that the exposed metalwork on the appliance is securely connected to the safe earth potential. During the test a high current (up to 25A) is passed through a circuit comprising the appliance earth conductor of the supply lead, the exposed metal on the appliance and the temporary test lead from the appliance tester. If the exposed metal work is securely connected electrically to the conductor, the resistance of the above circuit will be low. To be acceptable it must be between 0 and 0.1 Ohms (0.5 Ohms for low current appliances). This test must be carried out on all exposed metal work. If the resistance is too high, the protection afforded by earthing will be limited.
If the reading on the appliance tester indicates a high resistance or the fail indicator lights, then this must be investigated. First check the logged value for the equipment. It may be a low current appliance. If the reading is the same as the previous recorded value then this may be accepted (the resistance of thin mains leads may be appreciable e.g. 2.5 metres of 0.5 sq mm cable is itself around 0.1 Ohms). A particularly long lead or extension cable may also have an appreciable resistance. If this is the case get advice as to whether a circuit breaker should be fitted.
Check the security of the connections in the mains plug although this should already have been done during the physical inspection. Do not progress with further tests until this fault has been cleared.
The second essential test for class 1 appliances is the insulation test. This is used to ensure that a breakdown of the insulation cannot occur between any live parts within the appliance and parts of the casing that the user may touch. The appliance tester must be able to deliver a 500V DC test voltage for all loads of 2 Mohms upwards. The test may be performed as many times as you like without causing undue stress to the appliance under test. Note that the test procedure is slightly different for class 1 and class 2 appliances.
The appliance under test is switched on. If the appliance is earthed then the insulation test is carried out between the earth pin and the combined live and neutral pins on the plug. This relies on a satisfactory result for the earth bond test. If the earthing is faulty this test should not be performed as the results would be totally invalid.
Although the essential tests must be carried out in the order described the optional tests may be carried out in any sequence, but the flash test should only be carried by fully trained personnel preferably under workshop conditions. If an appliance has been recently repaired the essential earth bond and insulation test must be repeated first then the optional test can be carried out. The optional tests, although straightforward, can be difficult to interpret and should therefore only be authorised, carried out and interpreted by highly skilled and preferably electrically qualified personnel.

What type of Equipment Should be Tested

The equipment to be tested will normally be constructed in one of 3 basic classes designated Class I, II or III under British Standard 2745. (Class O equipment which has no provision for the earthing of metalwork is of foreign origin and safe only in earth-free zones.
Class I Apparatus is provided with basic insulation. In addition the metalwork is earthed so that it cannot become live in the event of an insulation failure.
Class I Apparatus is the most common type; its safety depends on the integrity of its one layer of insulation and the earth bonding of its metalwork. If there is an insulation fault, the metalwork is entirely dependent on the integrity of the earth bonding if it is not to attain a hazardous voltage. Inspection of the earthing conductors and connections is very important where this type of apparatus is used.
Class IIA (All-insulated) Apparatus has two layers (or equivalent) of insulation, one of which covers or comprises the outer casing so that metalwork cannot be touched. Class IIB (Double-insulated) Apparatus has all exposed metalwork separated from the conductors by two layers of insulation so that the metalwork cannot become live. There is no earth connection and the operator's safety depends on the integrity of the two layers of insulation. The first layer is basic or functional insulation and the second layer is supplementary or protective insulation. In some cases a single insulation layer is allowed if it is mechanically and electrically equivalent to double insulation.
Class II equipment is marked with the symbol (please consult "Electrical Safety Testing" booklet for symbol).
Class III Apparatus operates on safety extra low voltage (SELV) i.e. at a voltage not exceeding 50V AC between conductors or to earth. The apparatus has basic insulation only and unearthed metalwork.
Class III motor operated tools are not widely used in the UK as they are difficult to obtain. They are larger than comparable mains voltage tools and larger cables have to be used to avoid volt drop problems. 50V or 25V handlamps, soldering irons and special purpose heaters are commonly used.
While the isolating transformer provides the essential electrical separation from the mains supply, some users also choose to earth the centre tap of the low voltage winding of the transformer and also earth the exposed metalwork of the apparatus. This is strictly speaking a Class I extra low voltage installation with a line-earth voltage of half the system voltage.
Class III equipment should not be fitted with plugs or connectors of a type standardised for operation at mains voltage.

 

[amberleaf]

Priority Equipment and Equipment with Special needs

When instituting a test programme, priority should be given to certain types of equipment whose usage and operational environment mean that they are more likely to give rise to electrical danger. Examples of these include the following:
• Handheld tools such as drills.
• Equipment with long cables which might be easily damaged and those with easily damaged electrical components e.g. floor polishers, vacuum cleaners, desk lamps.
• Equipment with which water is intimately involved e.g. kettles, steam irons, thermostat baths, water stills, electrophoresis apparatus.
• Equipment normally used in a wet or humid place e.g. in kitchens, hot rooms, cold rooms, aquaria, hydraulics laboratories.
• Equipment used in areas where there is a high chance of damage by corrosive chemicals, oils, solvents or sunlight. These are especially liable to damage the insulation.
• Equipment used outdoors.
Extension leads should be treated in a similar fashion to removable mains leads. They should have unique serial numbers and be tested at regular intervals. The following tests are recommended:
1. Resistance of the earth conductor.
2. Insulation resistance testing.
3. Continuity of each conductor.
4. Polarity of phase, neutral and earth connections.
As the length of the extension cable will have an effect on earth resistance, compare the test value with the resistance expected for the particular conductor size. Extension leads are likely to be exposed to a high level of abuse. Visual inspection of the insulation is therefore extremely important as is examination of the terminations to the plug and socket.
Modern low voltage transformers are manufactured to British Standard 3535 which allows either Class I or Class II construction. The transformer should be treated as any other piece or portable equipment. An additional test may be required to ensure that the primary voltage does not appear on the secondary winding. A flash test conducted on a Class I transformer will have additionally proved the insulation between the primary winding and the earthed screen thus ensuring primary/secondary isolation. The flash test conducted on a Class II transformer will not have tested the integrity of the insulating barrier between primary and secondary winding. A high voltage insulation test will therefore be required between the input and the output connections.
Portable Appliance Testers are in themselves items of portable equipment and will therefore require safety testing in accordance with the criteria described elsewhere in this booklet. In addition, the equipment should be subjected to a full certified calibration procedure on an annual basis.
There are some common types of equipment which are not connected to the electrical system by a 13A plug but which are nevertheless the responsibility of the Department. Examples are centrifuges, electron microscopes, X-ray equipment and workshop equipment such as milling machines and lathes. Special arrangements, in some cases with the supplier, will be necessary to deal with these items. The fact that they are not portable (nor indeed readily transportable) may mean that testing can be carried out less frequently but the location and usage does need to be considered.

Frequency of Testing

There are no absolute rules regarding how often an item of electrical equipment should be tested. The Health and Safety Executive Guidance Notes on the safety of electrical apparatus advise "regular testing" and this is generally interpreted as a requirement for annual testing. However, circumstances and conditions of use will vary and it is therefore up to Departments to assess the conditions of use of each piece of apparatus to determine, using the following guidelines, the test regime which is most appropriate.
The criteria which should be used to assess the need for testing the equipment includes the following:
1. Whether the equipment is portable i.e. Is it always used held in the hand (as opposed to being transportable) so that there is a greater likelihood of the apparatus being dropped while is use as opposed to being permanently installed on a desk.
2. Whether its usage is continuous or infrequent and whether the nature of its task is inherently rough.
3. The age of the equipment.
4. If the equipment is regularly moved or transported and by what means.
5. The overall competence of personnel using the equipment.
6. The environment of usage i.e. indoors v outdoors, hazardous atmospheres, likelihood of exposure to water, solvents, oils etc.
7. The results of previous tests.
Based on these criteria some suggested test periods are as follows:
Handheld portable tools should be tested every 6 months.
Equipment identified as being a priority should be tested not less than once every 12 months.At least 25% of double insulated (class II) equipment should be tested each year with the aim of testing each piece of this type of apparatus every four years.
Within this general framework, most equipment in laboratories or workshops should be tested at intervals of between 12 and 24 months, depending on the 7 criteria listed above. Most equipment in offices, libraries and similar accommodation should be tested every 24-36 months.

Test Precautions

The safety test programme consists of each item of apparatus receiving a visual inspection, essential tests (earth bond and insulation) and in some cases, additional tests such as flash, operational and earth leakage tests. Of the essential tests, the insulation test is always carried out but the earth bond test in only performed on class 1 appliances. The optional tests should be performed at the discretion of the competent person in charge, perhaps because there is some reason to think the appliance may become unsafe. Some optional tests should not be carried out more than is necessary as they may weaken the insulation of the appliance.
The following precautions are necessary during the testing of the apparatus:
1. Precautions for Essential Tests
• Check the test results sheet and identify the class of the appliance, its operating voltage and any special precautions which should be observed.
• Check that the environment in which the tests are to be performed is free from hazards, e.g. the earth bond test or insulation test may produce a spark which would ignite flammable vapours or fine dust.
• Disconnect all other equipment from the appliance under test. This not only guards against potential hazards but also against spurious results.
• Ensure that no one including yourself touches the appliance during testing. If the appliance is faulty they may receive an electric shock.
• Ensure that any test equipment is plugged into a proper earthed mains supply.
• Some tests require that the appliance under test is switched on. You may need to clamp the on/off button on some appliances. Ensure that no damage is possible due to the operation of the appliance e.g. an electric drill would need to be suitable secured during the test.
• Stop testing immediately an appliance fails one particular test. Do not go on to the next test because the appliance may be in a dangerous state.
• Always do the tests in order of, first, visual inspection then the earth bond test for class 1 appliances followed by the insulation tests.
2. Precautions for Optional Tests
All the precautions above apply to the optional tests plus those give below:
• Check the initial test results and ensure that any given test may be applied to the appliance. Electronic equipment may use semi-conductor devices and interference suppressors which will not withstand certain tests. The equipment manufacturer should be asked to define which tests may not be undertaken. Motors such as inductively stalled types will not pass the low voltage load test.
• Take particular care when performing a flash test as the very high voltages can be dangerous. It is best to have a second person on hand so that if you receive a shock, they can remove the power and resuscitate you.

4. After an initial physical evaluation, electrical tests are carried out to ensure the continued safety of each appliance. The test results are logged. Equipment which fails a safety test is withdrawn from use, the cause investigated and it is either repaired or replaced.

'Wattage' of Equipment = Fuse Rating
'Wattage' of Equipment Fuse Rating
Up to 600 Watts 3 Amps
Between 600 Watts and 1000 Watts (1KW) 5 Amps
Between 1KW and 3KW (3000 Watts) 13 Amps

Equipment that is rarely moved and is not at risk of damage (e.g. computers) is likely to be low risk and requires less frequent inspection than equipment that is frequently moved, might be used in a damp environment (e.g. kettles, water baths) or may be subject to damage.
Equipment used in an office environment is rarely of the type that would be considered high risk. High risk equipment includes equipment such as portable electrical hand tools.
As the title visual inspection implies, all you really need to do is look closely at the equipment. More than 90% of equipment faults can be found by visual inspection.

Current Fire Extinguisher Colour Codes ( New EEC Colures / BS- )

(1) Just ↔ Red ( Water Only ) ↔ Water
● Paper , Wood , Textiles & Solid Materials Fires

(2) Red ( With Blue Mark on Red Body ) ↔ Powder
● Liquid , Electrical , Wood , Paper & Textile Fires

(3) Red ( With Cream Mark on Red Body ) ↔ AFFF Foam
● Liquid , Paper , Wood , Textile Fires

(4) Red ( With Black Mark on Red Body ) PS. Do Not Hold Horn When Operating ↔ Carbon Dioxide ( CO2 )
● Liquid , Electrical Fires ,

N.B (a) Both Colour Codes are Still in Use ,
(b) a New Class F Extinguisher is now Available for Cooking Oil & Fat Fires ,

 

[amberleaf]

That’s how to Keep the Reaper at Bay !!!!!

Isolation

(1) Remove the Load from the Circuit to be Isolated
(2) Open the Isolator and Lock Off
(3) Prove the “ Approved Voltage Tester “ on a Know Source ( Proving Unit )
(4) Test the Circuit to Confirm as “ Dead “
(5) Re-Prove the “ Approved Voltage Tester “ on the Proving Unit
(6) Fit Warning Notices at the Point of Isolation
(7) Keep the Key in your Pocket Ensuring Only you can Re-Energise the Circuit

The Source of Supply may Not have Means of Locking Off Afforded to it ,
If that is the Case , Look for Alternatives , Lock the Whole Switch Room Off if Necessary ,
Physically Disconnect the Supply , if you Have to Leave a Lookout at the Point of Isolation ,

Inform People of What you are Doing ,

→ → Your Safety is Your Own Responsibility ← ←

The Above May or Not be Factual ,
The Point is Every Time an Electrician is Electrocuted it is Because the Correct “ Isolation Procedure “ has Not been Followed ,

Continuity of Protective Conductors
612.2.1
Instrument ( Continuity Tester ) Low Ohms
No Load Voltage between 4 & 24V d.c. or a.c.
Short-Circuit Current of Not Less than 200mA Ia / Ief ( Exposed Conductive Parts )

On New Installations’ or where the Supply may be Isolated then the Protective & Bonding Conductors’ May be Disconnected for the Duration of the Test
Where this is Not Possible Earth Loop Impedance Tests may be Made to Verify Continuity ,
Instrument , Main Protective Bonding Conductor , Cables Résistance should Not Exceed 0.05Ω
The Résistance of a Typical Supplementary Protective Bonding Conductor Should Not Exceed ( R = 50 V ÷ Ia )

411.8.3
“ Requirements for Fault Protection “

Where Fault Protection is Provided by an RCD , the Product of the Rated Residual Operating Current ( I∆n )
In Amperes and the Earth Fault Loop Impedance in Ohms shall Not Exceed 50 V

“ Circuit Protective Conductor “
Does Not Rise Above Earth Potential More than 50V ,

Overcurrent Protective Device is Used , Zs / Uo ÷ Ia ( 230 ÷ Amp = Zs )

Damage Under Earth Fault Conditions “ Ohms “ Ia / Uo ÷ Zs ( 230 ÷ Zs = Amp )

Requirements Relating to Items Required for Typical Distribution Board Schedule 514.9

Domestic Electrician Installation of Cables , 521.10.1 , Meter Tails ( IP4X )
434.3 / (iv) Csa 514.3 530.3.4 - Consumers Controlgear ,

527.2.1 / FireFoam ( fire-resistance

120.3
Any Intended Departure from these Parts Requires Special Consideration by the Designer of the Installation and Shall be
Noted on the Electrical Installation Certificate Specified in Part 6 ( Inspection & Testing )
The Resulting Degree of Safety of the Installation shall be Not Less than Obtained by Compliance with the Regulations ,

132.13
Documentation for the Electrical Installation
Every Electrical Installation shall be Provided with Appropriate Documentation , Including that Required by
Regulation 514.9 , Requirements Relating to Items Required for Typical Distribution Board Schedule , Part 6 & where Applicable Part 7

134.1.7
Where Necessary for Safety Purposes , Suitable Warning Signs and / or Notices shall be Provided

610.1 Initial Verification ( Testing for New Electrical Installation Work )
Every Installation shall , During Erection and on Completion before being put into Service , be Inspected & Tested to Verify ,
So far as is Reasonably Practicable , that the Requirements of the Regulations have be Met

134.2.1
Initial Verification ( Initial Inspection & Testing )
During Erection and on Completion of an Installation or an Addition or Alteration to an Installation ,
And before it is put into Service , Appropriate Inspection & Testing shall be Carried Out by Competent Persons to Verify
That the Requirements of this Standard has been Met ,

( Appropriate Certification shall be Issued in Accordance with Sec 631

631.1
Upon Completion of Verification of a New Installation or Changes to an Existing Installation , an Electrical Installation Certificate
( based on model given in App 6 p-331 , shall be Provided , Such Documentation shall Include Details of the Extent of the
Installation Covered by the Certificate , Together with a Record of the Installation and the Results of Testing
( Schedule of Inspection and Electrical Installation Certificate )

Paperwork that should be Issued on Completion of New Installations ,
Schedule of Test Results , Schedule of Inspection & Electrical Installation Certificate

632 Initial Verification
632.1
Following the Initial Verification Required by Chapter 61 p-155 an Electrical Installation Certificate together with a
Schedule of Inspection , Schedule of Test Results , shall be given to the Person Ordering the work

632.2
The Schedule of Test Results shall Identify Every Circuit , Including its Related Protective Device(s) and shall
Record the Results of the Appropriate Tests and Measurements ,
632.4
Defects or Omissions Revealed During Inspection & Testing of the Installation Work Covered by the Certificate shall be Made
Good before the Certificate is Issued , ← ←

611 Inspection
611.1 Inspection shall Precede Testing and shall Normally be Done with that Part of the Installation Under Inspection Disconnected
From the Supply , ( That Appropriate form of Disconnection is Isolation )

Regulation 12 Electricity at Work Regulations 1989

( Maximum Demand & Diversity should be Determined before an Installation is to begin ) ←←

311 Maximum Demand & Diversity
311.1 For Economic & Reliable Design , the Maximum Demand of an Installation shall be Assessed
In Determining the Maximum Demand of an Installation or Part thereof , Diversity may be taken into Account ,

314.4
Where an Installation Comprises more than One Final Circuit , each Final Circuit shall be Connected to a Separate Way
In a Distribution Board , the Wiring of each Final Circuit shall be Electrically Separate from that of Every Other Final Circuit ,
So as to Prevent the Indirect Energizing of a Final Circuit Intended to be Isolated ,
( This is a requirement in Domestic ) ←← Part P ,

 

[amberleaf]

● “ Continuity of Protective Conductors “ ( Dead Test ) ( Guides Note -3 ) GN-3

Instrument , Continuity Tester ( Set on Low Ohms Scale )
( Multimeter can be Used to Measure the Voltage between two Positions )

612.2.1 No Load Voltage between 4 / 24V
Short Circuit Current of not Less than 200mA ( Ia Ief )

Earth Loop Impedance Test to Verify Continuity ( Measures Résistance of Conductors’ )

● “ Continuity Ring Final Circuit Conductors “ ( Dead Test )

Instrument , Continuity Tester ( ( Set on Low Ohms Scale )

612.2.2 No Load Voltage between 4 / 24V
Short Circuit Current of not Less than 200mA ( Ia Ief )

(1) Test is Undertaken to Ensure that all Conductors of the Ring Final Circuit are Continuous ,
(2) Conductors’ have Not been Bridged Creating Multiple Loops ,
(3) That all Connections are Electrically and Mechanically Sound ,

Step 1 , Isolated and Disconnected from The Supply

Step 2 , Phase & Neutral Conductors are Now Cross Connected so that the Outward Leg of the Phase Connects to the
Neutral and the inward Leg of the Phase Connects to the Outward Leg of the Neutral
Readings are Now taken between Phase and Neutral at each Socket
Readings at each Socket Outlet should be within 0.05Ω of each Other
(i) Failure to be within this Limit would Highlight Loose Terminations
(ii) Significant Increase at a Socket would Indicate that it is a Spur , Bridges within the Circuit would be Indicated by a
Gradual Decrease on the Return Leg

Step 3 , Phase & CPC Loops are now Interconnected so that the Outward Leg of the CPC Connects to the inward Leg
Of the Phase and the inward Leg of the CPC Connects to the Outward Leg of the Phase ,

(iii) Measured Value may be Recorded as ( R1 + R2 )

● “ Polarity “ ( Dead Test )

Instrument , Continuity Tester ( Set on Low Ohms Scale )

612.6 No Load Voltage between 4 / 24V
Short Circuit Current of not Less than 200mA ( Ia Ief )

It must be Confirmed by Test , Every Fuse and Single-Pole Control and Protective Device is Connected in the Line Conductor Only ,
612.6 (ii)
Contact Bayonet and Edison Screw Lampholder(s) have the Outer or Screwed Contacts Connected to the Neutral ,
The Phase Conductor is Connected to the Centre Termination of an Edison Screw Lampholder Only , ←←

612.6 (iii)
Wiring has been Correctly Connected to Socket-Outlets and Similar Accessories ,

(i) All Sockets Polarities’ are Correct ,
(ii) That the Polarity of the Incoming Supply is Correct / Before the Supply is Energised ,
Your Checking to Ensure the Supply Authorities Polarity is Correct ,

Acceptable to Place a Temporary Bridge Between Phase & Earth in the Consumers Unit ,

(i) Test between Switched Live & Earth at the Ceiling Rose to Confirm Polarity
(ii) Operate Switch to Confirm Polarity
(iii) HSE Guidance Note GS-38 ↔ Electrical Equipment
→ You Should always Prove Isolation ← (iv) Use a Proving Unit
Then Test for Circuit is Dead , then Prove GS-38 it still Works
(v) Once the Supply is Energised Correct Polarity of the Incoming Supply may be Established Using An Approved
Approved Voltage Tester at the Mains , ( after Proving that GS-38 Voltage Indicator is Working )

(vi) Remember to Remove your Temp link , Phase & Earth

Once the Inspection & Testing has been Completed it is then of Vital Importance that the Relevant Documentation is Completed
Three Signatures’ are Required on the Electrical Installation Certificate , ( Three Signatures are still Required )

(i) Designer (ii) Installer (iii) Tester

Appendix 6 , (ix) When making Out and Signing a Form on behalf of a Company or Other Business Entity ,
Individuals should State ( for Whom they are Acting ) 632.3

Electrical Installation Certificate ,
To be Used When One Person is Responsible for the Design , Construction , Inspection & Testing of an Installation

Electrical Installation Certificate
This Certificate is Intended to be Issued Only for a New Electrical Installation or for New Work Associated with an
Addition or Alteration to an Existing Installation ,
It should Not have been Issued for the Inspection of an Existing Electrical Installation , A “ Periodic Inspection Report “
Should be Issue for such an Inspection ,

There are Three Main Reasons why we Certificate an Installation ,
(i) Addition to an Installation (ii ) an Alteration to an Installation (iii) New Installation

Which Certificate is Issued the Original should be Given to the Person Ordering the Work and a Duplicate by the Contractor , 632.1

Particular Care should be Given when Completing the Extent and Limitations Details of Periodic and Close Liaison ,
With the Client , is Essential at this Time , This is to Ensure that the Client is Fully Informed of what will and what Not be Tested ,
( All must be Negotiated with the Client )

631.2 Upon Completion of the Periodic Inspection & Testing of an Existing Instillation ,
Periodic Inspection Report , Shall be Provided , such Documentation shall Include Details of the Extent of the Installation & Limitations
Of the Inspection & Testing Covered by the Report , Together with a Record of the Inspection and the Results of Testing ,

621.4
The Extent and Results of the Periodic Inspection & Testing of an Installation , or any Part of an Installation , shall be Recorded ,

Person Ordering the Work : Periodic (i) First Periodic Test – Designer / Installer
(ii) Further Periodic Test – Tester / Inspector
(iii) Extent & Limitations Agreed with / Person Ordering The Work ,

Periodic Inspection Report
Notes , (5 ) p-339
The Extent and Limitations “ Box should fully Identify the Elements of the Installation that are Covered by the Report and
Those that are Not this Aspect having been Agreed with the Client and Other Interested Parties before the
The Inspection & Testing is Carried Out ,

The “ Extent and Limitations “ Box should fully Identify the Extent of the Installation Covered by this Report and any Limitations on the Inspection & Tests the Contractor should have Agreed these Aspects with you and any Other
Interested Parties ( Licensing Authority , Insurance Company , Building Society etc , before the Inspection was Carried Out

4118.3
Where a Circuit-breaker is Used the Maximum Value of Earth Fault Loop Impedance ( Zs ) shall be Determined by the
Formula in Regulation 411.4.5 Alternatively , the Values Specified in Table 41.4 may be Used instead of Calculations
For the Nominal Voltages ( Uo ) and the Types and Ratings of Overcurrent Device listed therein ,

What is the Maximum Earth Fault Loop Impedance Allowed when Using a 32A Type C
Circuit Breaker Giving s Disconnection time of 5sec , the Nominal Voltage to Earth ( Uo ) is 55v ↔ 41.6 ( 0.17Ω )



PS is this Helping anybody Please let me Know ,
When I don’t hear anything My Computer does Hand Stands , Amberleaf
Keep at it Chaps there’s always tomorrow ,

The On Site Guide & Guidance Note 3

Contain Detailed Information on how to Carry Out a Series of Electrical Tests on an Installation ,
612.2.1 Continuity of Protective Conductors ( Dead Test ) GN- 3
612.2.2 Continuity of Ring Final Circuit Conductors’ ( Dead Test ) GN- 3
612.3. Insulation Résistance ( Dead Test ) GN- 3
612.6 Polarity ( Dead Test ) GN- 3 By Continuity Methods
612.7 Earth Electrode Résistance ( Dead Test ) GN- 3 Battery ,

612.9 Earth Fault Loop Impedance ( Energized ) GN- 3
612.11 Prospective Fault Current ( Energized ) GN- 3
612.13. Functional Testing ( Energized ) GN- 3

In Addition to an Inspection these Test form the Basis of any Electrical Commissioning Process of an Electrical Installation ,

There are Two Main Types of Test / Commissioning Undertaken there are Initial Testing ,
And Periodic Testing , as the Name Suggests Initial Testing is Undertaken to Ensure the Installation is Safe and in Compliance with BS-7671 Prior to being Handed Over to the Client ,

Whilst a Periodic “ Report “ is Undertaken at Regular Intervals whilst the Installation is in Service to Ensure the Installation
Remains Safe and Fit for Use ,

The Sequence of Electrical Tests Undertaken Differs Slightly Between the Two ,

 

[amberleaf]

RCD is Provided for Supplementary Protection Against Direct Contact its Operating Current must Not Exceed 30mA
( Must Operate in the Time Not Exceed 40mS at Residual Current of x5 its Rated Current )

Additional Protection RCD ( 612.10
The Verification of the Effectiveness of the Measures Applied for Additional Protection is Fulfilled by Visual Inspection & Test
Where RCDs are Required for Additional Protection the Effectiveness of Automatic Disconnection of Supple by RCDs shall
Be Verified Using Suitable Test Equipment According to BS-EN 61557-6 to Confirm that the Relevant Requirements’ are Met ,

612.1
The Tests of Regulations 612.2 / 612.13 Where Relevant , shall be Carried Out and the Results Compared with Relevant Criteria

30mA RCD

Test Button to Select 30mA

Half Current ( 15mA ) Test , 0º ≈ Positive Half Cycle ( RDC should Not Trip ) ½
Half Current ( 15mA ) Test , 180º Negative Half Cycle ( RDC should Not Trip )

Full Current ( 30mA ) Test , 0º ≈ Positive Half Cycle ( RDC should Trip ) x1 40mS
Full Current ( 30mA ) Test , 180º Negative Half Cycle ( RDC should Trip )

Five times Current ( 150mA ) Test , 0º ≈ Positive Half Cycle ( RDC should Trip ) x5
Five times Current ( 150mA ) Test , 180º Negative Half Cycle ( RDC should Trip )

100mA RCD 0º or ( Positive ) 180º ( Negative )

Test Button to Select 100mA

Half Current ( 50mA ) Test , 0º ≈ Positive Half Cycle ( RDC should Not Trip ) ½
Half Current ( 50mA ) Test , 180º Negative Half Cycle ( RDC should Not Trip )
Full Current ( 100mA ) Test , 0º ≈ Positive Half Cycle ( RDC should Trip ) x1
Full Current ( 100mA ) Test , 180º Negative Half Cycle ( RDC should Trip ) RCDs Remember L to E fault

Note that the Five Times Current Test is Not Required for a 100mA RCD

State Four Items of Electrical Equipment that would Require Functional Testing
( Functional Checks ) 612.13
(i) RCDs
(ii) Circuit Breakers
(iii) Isolators’
(iv) Cooker , Switches

Devices Used for Isolation , Switching for Mechanical Maintenance , Emergency Switching & Functional Switching , T/ 53-2 p-117
PS , Breakers can Now be Used as Primarily as Switches’ ,

Domestic Electricians read up on your ( TT Systems ) Uncle Sam is Watching

If Any Test Indicates a Failure to Comply , that Test and any Preceding Test , the Results of which may have been Influenced
By the Fault Indicated , shall be Repeated after the Fault has been Rectified ,

The Tests of Regulations 612.2 Continuity of Conductors to 612.6 where relevant , shall be Carried Out in the Order before the Installation is Energised , Where the Installation Incorporates an Earth-Electrode ,
the Test of Regulations 612.7 Shall also be Carried Out Before the Installation is Energised , GN-3 ( TT Systems ) or

Some Methods of Test are Describe in IEE Guidance Note 3 Inspection & Testing ,
Other Methods Are Not Precluded Provided they give Valid Results ↔ it is in the Regs , 2008 17th p-157

The Tests of Regulations 612.2 Continuity of Conductors to 612.6 where relevant , shall be Carried Out in the Order before the Installation is Energised , Where the Installation Incorporates an Earth-Electrode ,
the Test of Regulations 612.7 Shall also be Carried Out Before the Installation is Energised , GN-3 ( TT Systems ) or

Note that the Five Times Current Test is Not Required for a 100mA RCD

State the Action to be Taken Regarding the Earthing Conductor Before Measuring the Résistance of an Earth Electrode
GN-3 ( Earth Electrode Testing )
(i) DO NOT DISCONNECT any Protective Conductors BEFORE Isolating the Supply ←←← think about this One
(ii) Disconnect Earthing Conductor at ( MET ) ↔ Link in D/B , to Avoid Parallel Earth Paths

State Two Reasons why it is Necessary to Measure External Earth Fault Loop Impedance at the Origin of an Installation ,
GN-3 ( Determining Ze )
(i) To Verify an Earth Connection
(ii) The Value is Equal to or Less than the Value Determined by the Designer ,

State the Test Voltage and Minimum Acceptable Value of Insulation Résistance for the Following Circuits
(i) 400v 3 Phase Motor ( 500v dc 1.0MΩ )
(ii) 760v Discharge Lighting Circuit ( 1000v dc 1.0MΩ )
(iii) 45v FELV Circuit ( 250v dc 0.5MΩ

Identify one other Test that is Automatically Preformed when undertaking a Ring Circuit Test
GN-3 ( Continuity of the Ring Final Circuit ) 612.2.2
Polarity , 612.2

Identify the Test that should be Applied to Verify Polarity after the Supply is Energised ,
GN-3 ( Polarity )
Test to Verify Correct Polarity of the Incoming Live Supply , ( Test Made at the Origin Using Approved Voltage Indictor GS-38 )

State the Correct Sequence for Under taking an Insulation Résistance Test florescent Light
Circuit Containing two-way Switching
GN-3 ( Insulation Résistance Testing )
(1) Supply Must be Isolated ( Dead Test )
(2) All Lamps Removed
(3) Insulation Résistance Test between Line Conductors and Neutral
(4) Insulation Résistance Test between Line Conductors and CPC
(5) Two-Way Switches’ Operated During Test ,

State items of Equipment / Components that may Need to be Removed prior to Carrying out a Test for Insulation Résistance
On a Circuit 612.3
GN-3 ( Insulation Résistance )
Pilot or Indicator Lamps
Dimmer Switches
Touch switches

Under what Circumstances would it be Appropriate to Issue a Single Signature Electrical Installation Certificate
GN-3 ( Certificates )
Where Design , Construction Inspection and Testing is the Responsibility of One Person ( in the Regs ,

State the Necessary Action that should be taken by an Inspector on Discovering a Damage Socket-Outlet
With Exposed Live Parts During a Periodic Inspection & Test
GN-3 ( Required Competence )
Make an Immediate Recommendation to the Client to Isolate the Defective Part

State the Formula Used to Calculate Impedance ( Zs ) at the Furthest Point within a Circuit
GN-3 ( Earth Fault Loop Impedance ) 612.9
( Zs = Ze + R1 + R2 )
Where Ze is by Measurement or Enquiry
And ( R1 + R2 ) by Measurement ,

State the Maximum Recommended Value of Résistance for an Earth Electrode p-50 Note 2
GN-3 ( Earth Electrode for RCDs )
(i) Electrodes having Resistances’ in the Excess of 200Ω will Require Further Instigation , ↔ “ Houston we have a problem “
(ii) Note , Electrodes Resistances Obtained in Excess of 200Ω May Indicate Unstable Soil Conditions

Formula for Estimating Energy Consumption
You can Use this Formula to Estimate an Appliances Energy Use ,

( Wattage x Hours Used per Day ÷ 1000 = Daily Kilowatt-Hour ( kWh ) Consumption .
( 1 kilowatt ( kW ) = 1,000 Watts )

Multiply this by the Number of Days you Use the Appliance During the Year for the Annual Consumption ,
You can then Calculate the Annual Cost to Run an Appliance by Multiplying the ( kWh ) per Year by your
Local Utility’s Rate per Year by your Utility’s Rate per ( kWh ) Consumed ,

Note : To Estimate the Number of Hours that a Refrigerator Actually Operates at its Maximum Wattage ,
Divide the Total Time the Refrigerators’ is Plugged in by Three Refrigerators’, Although “on” all the Time ,
Actually Cycle On and Off as Needed to Maintain Interior Temperatures ,

Window Fan ,
( 200 Watts x 4 Hours / Day x 120 Days / Year ) ÷ 1000
= 96 ( kWh ) x 8.5 % / ( kWh ) £ 8.16 Year - ( 200 x 4 x 120 Div 1000 ( 96 x 8.5 = 8.16 )

Computer / Monitor
( 120 + 150 Watts x 4 Hours / Day x 365 / Year ÷ 1000
= 394 ( kWh ) x 8.5 % / ( kWh )
= £ 33.51 / Year


Standard Light Bulb 4 Hour a Day 100 Watt £ 14.60 per Year
Low Energy Light Bulb 4 Hour a Day 18 Watt £ 2.63

Aquarium = 50 – 1210 Watts
Clock Radio 10
Personal Computers ( CUP / Awake / Asleep = 120 / 30 or Less
Monitor – Awake / Asleep = 150 / 30 or Less
Laptop – 50
Refrigerator ( Frost Free , 16 cubic feet ) = 725

Cost per year
This I hope this will Help you Lionel ,

 

[amberleaf]

17th BS-7671 : 2008 ♫ ♫ ♫ Old to New
GN3
The Requirement for 40mS at a Residual Current of x5 Operating Current comes from Regulation 415.1.1 when the RCD is used

The Use of RCDs with a Rated Residual Operating Current , Not Exceeding 30mA and Operating Time Not Exceeding 40mS
Residual Current x5 is Recognised In a.c Systems as Additional Protection ,
( Provision for Basic Protection / Provision for Fault Protection ) Right One ,

Protection Against Electric Shock ( Chapter 41 p-44 17th

16th BS-7671 2001: ←←←
They are Still a lot of Old Notes and Stuff from the Internet ,

( i) Protection in Use Without A Fault ( Now Designated Basic Protection Was Referred to as Protection Against ( Direct Contact
(ii) Protection Under Fault Conditions ( Now Designated Fault Protection Was Referred to as Protection Against ( Indirect Contact

PS , Supplementary Protective Bonding Conductors’ is Complementary Measure for “ Fault Protection “

Functional Testing 612.13 / RCD Testing Detail a “ Quarterly Test “ , Regulation 514.12.2 Domestic Electricians

MCB's to BS EN 60898 RCBOs to 61009-1 for disconnection times of 0.4 & 5 sec

411.3.2.2 the Maximum Disconnection time Sated Table 41.1
( Shall be Applied to FINAL RING CIRUITS NOT EXCEEDING 32Amps TN-systems 0.4 sec ONLY )

411.3.2.3
In A TN-System , a Disconnection time ( 5sec Final Ring Circuits EXCEEDING 32Amps ONLY )

The Maximum Disconnection Time TN-Systems ( 230v to Earth 0.2 sec Only )

Remember to Keep You ( Earth Impedance Ω Zs Very Very Low )

Protection Against Electric Shock ,
( That Live Parts , Such as Energized Conductors , Must Not be Accessible )
( The Conductive Parts which are Accessible , Such as Metal Enclosures of Equipment or Metal Pipes , Must Not be Live )
Must be Achieved both in Normal Conditions ( No Faults on Electrical Systems )

(i) By Touching Live Parts at Different Potential , Max , Touch Voltage of 50 Volts
(ii) A Live Part and Earth Potential ,

● Standards Documents , BS / British Standards ( EN / European Standards ( ISO / Worldwide British Standards ,

For the Apprentice ,

( Moulded-Plug ) a Non-wiriable Plug , the Manufacture of Which is Completed by Insulating Material Moulded Pre-Assembled
Component Parts and the Terminations of Flexible Cord ,
( Fuse Plug ) a Plug having Provision for a Replaceable Cartridge Fuse Link ,

Terminal , a Means by which the User can Make an Electrical Connection between the Appropriate Flexible Cord and the
Conducting Parts of the Plug Without the Use of Special Purpose Tools ,

( Screw-Type-Terminal )
A Terminal in Which the Connection is Made Direly by Means of Screws or Nuts of any Kind or Indirectly through an
Intermediate Metal Part such as a Washer , Clamping Plate or Anti-Spread Device on Which the Screw Bears Directly ,

Example of Screw-Type Terminals ,
A Pillar Terminal is a Terminal in which the Conductor is Inserted into a Hole or Cavity ,
Where it is Clamped Under the Shank of the Screw or Screws ,

A Screw Terminal is a Terminal in Which the Conductor is Clamped Under the Head of the Screw ,

A Screw Terminal is a Terminal in Which the Conductor is Clamped Under a Nut ,

( Clamp-Type ) Screwless Terminal ,
A Terminal in Which the Connection is Made by Clamping the Conductor of Flexible Cord between two Metallic Surfaces
Without the Use of a Screw ,

( Fuse Carrier ) A Movable or Removable Part Designed to Carry , Retain , Cover and / or Remove the Fuse Link ,

Classification ,
(i) Rewirable or Non- Rewirable
(ii) For Normal Use or Rough Use ,
(iii) Fitted with Screw or Clamp Type ( Screwless ) Terminals ,

(i) for Screw Type Terminals the Clamping Screw Shall be Tightened with Torque to Two-Thirds of the Appropriate Value ,
(ii) for Clamp-Type ( Screwless ) Terminals the Connection shall be Made in Accordance with the Manufacturers Instructions ,

The Résistance between the Earthing Terminal or Termination and any Other Nominated Metal Part shall Not Exceed 0.05Ω

“ Fundamental Principles “

Protection for Safety 131.

Fundamental Reason for Inspecting & Testing an Electrical Installation is to Determine Whether a New Installation is Safe To be Put into Service ,

Following Statements
(i) Installations Must be Inspected and Tested on Completion and also During Erection
(ii) The Purpose of the Inspection is to Verify Equipment is Correctly Selected and Erected in Accordance with BS-7671
(iii) Precautions shall be Taken to Avoid Damage to Property During Inspection & Testing 131.1

131.1
The Requirements of this Chapter are Intend to Provide for the Safety of Persons , and Property against Dangers & Damage
Which May arise in the Reasonable Use of Electrical Installations ,

Or Whether an Exciting Installation is Safe to Remain in Service Until the Next Inspection is Due ,
● If it is Verified that New Installation , Work fully Complies with the Current Requirements’ BS-7671 Standards ,
● All Equipment Must be Suitable for its Intended Use ,

Initial Verification Chapter 63 ( Inspection & Testing ) Construction Inspection and Testing of the Installation shall ,
Which takes Account of their Respective Responsibilities for the Safety of that Installation , 632.3 / 632.1

Visual Inspection is Necessary Before Testing to Check Whether ( There is Adequate Access to Switchgear ,

Any Faults or Defects Indentified During an Initial Verification should be ( Made Good before Issuing the Certificate ,

632.4
Defects or Omissions Revealed During Inspecting & Testing of the Installation Work

During Inspection of a Distribution Board Containing Exposed Conducive Parts it Should be Verified that ,
( The Door can Only be Opened with a Key or Tool , 416.2.4. (i) )

Before Commencing an Initial Inspection and Test , the Inspector should have Copy of the ( Inspection Specification ,
the Following should Accompany the Inspection and Test Certificate ( Copies of the Inspection & Test Schedules ,

Initial Verification
Is Intended to Ensure that the Electrical Installation is Safe to but into Service , and that it is Likely to Remain in Such a Condition at Least Until the First Periodic Inspection ,

Something to Read ,

Electrical Contractors that Issue Inaccurate or Misleading Certificates or Reports
Are Liable to Criminal Prosecution by Trading Standards Officers
Under the Trade Descriptions Act 1968 or Other Relevant Legislation ,

The Term “ Inspector “ is Used to Describe a Person Responsible for Inspecting & Testing an Electrical Installation ,
All Persons Carrying Out the Inspecting & Testing of Electrical Installations Must be Competent to do So ,
This May come up in the Future ,

Safe Working Procedure ( Regulation 12 )
Means for Cutting of the Supply and for Isolation

611.1
Inspection shall Proceed Testing and Shall Normally be Done with that Part of the Installation under Inspection Disconnection from the Supply ,

Precautions for Work on Equipment Made Dead ( Regulation 13 )
Adequate Precautions shall be Taking to Prevent Electrical Equipment Which has been Made Dead
In Order to Prevent Danger while Work is Carried Out on or Near that Equipment becoming Live ,
( Electrician Must Carry Out Safe Isolation Procedure )

Open the Means of Isolation for the Circuit(s) to be Inspected

416.2.4
Where it is Necessary to Remove a Barrier or Open an Enclosure or Remove Parts of Enclosures
What you are Verifying at the Same Time ,
( Top of CU , IP4X 416.2.2 ( the Sides of the CU must Conform to IP2X 416.2.4 (ii)
( IP Rating for RCCBs / RCBOs / RCDs ( Front Plate is IP4X / Screw IP2X ( BS Finger Test )

Compliant with GS-38 with Regards to Test Leads
Prove the Correct Operation on a Suitable Voltage Test Instrument Against a Known Source

Test , with the GS-38 Voltage Test Instrument All Conductors of the circuit(s) you are Working on to Confirm that there’s No
Live Supply to the Equipment your Working On ,

Prove the Voltage Test Instrument Against the Know Source to Check that it was Functioning Correctly

Remember GN-38 Electrical Test Equipment / Test Equipment for Circuits with Rated Voltages Not Exceeding 650 Voltages

BS-EN 61010 GN-38
Equipment Included in Scope ,
This Part of IEC 61010 Specifies General Safety Requirements’ for Electrical Equipment Intended for Professional , Industrial Process ,
BS-EN 61557
Electrical Safety in Low-Voltage Distribution Systems up to 1000V a.c / 1500V d.c Equipment for Testing Measuring ,

Proving Unit for on Site-Testing and Verification of Electrical Test Equipment
Proving Unit Produces 690v AC / DC to Enable Voltage Indicators to be Checked
Unit is Suitable for Indicators with 230v / 415v ,

 

[amberleaf]

Electrical Installation Certificate is to be Used Only for the Initial Certification of a New Installation , or of New Work
Associated with an Alteration or Addition to an Existing Installation , Carried out in Accordance with BS-7671

Electrical Installation Certificate
( Requirements for Electrical Installations BS-7671 IEE Wiring Regulations

Nature of Installation Work
● Three Boxes are Provided to Enable the Contractor to Identify the Nature of the Installation Work ( p-332 ) ,

● New / This box should be Ticked Only if the whole Installation has been Installed as New , or if a Complete Rewire is Carried Out ,

● An Addition ( to an Existing Installation ) this box should be Ticked if an Existing Installation has been Modified by the Addition of One or More New Circuits’ ,

● An Alteration ( to an Existing Installation ) this box should be Ticked where One or More Existing Circuits have been Modified or Extended , or Items such as Distribution Boards and Switchgear have been Replaced ,

Where Appropriate , both the “ Addition “ and the “ Alteration ” Boxes may be Ticked ,

There are Three Main Reasons why we Certificate an Installation ,
(i) Addition to an Installation (ii ) an Alteration to an Installation (iii) New Installation ,

Visual Inspection of a New Installation must be Carried out ,
During Erection and Before Testing ,

Requirement of the Inspection Checklist ,
Prescience of a BS Mark or Other Suitable Certification ,
Correct Selection of Cable and Protection Devices ,
No Visible Damage ,

Inspection Domestic Consumer Unit would Need Verification for ,
Identification of Conductors’ ,
Rating and Type of Protective Devices
Correct Connection of Single-Pole Devices

Domestic Electrical Installation Certificate Three pages , 3x1

Signatories
Two Options are Available for Certification of the Installation ( Domestic Electrician )
(i) Where the Design , the Construction and Inspection & Testing are the Responsibility of One Person ,

“ Electrical Installation Certificate “ Signatories

(ii) Collectively Certified in the Section Headed , p- 332 / p-333 ( When Three People are Needed )
(1) ( For Design ) (2) ( For Construction ) (3) ( For Inspection & Testing )
Alternatively , where Approved Contractor Issuing the Certificate has Not been Responsible for the Design
And / or the Inspection & Testing of the Electrical Work , Certification of the Three Signatories must be Carried Out
Separately using the Three “ Particulars of Signatories to the Electrical Installation Certificate Design “ Construction ” Inspection & Testing “ Respectively ,

17th New Regulations that all Socket-Outlets up to 20A , Used by Ordinary Persons need to be RCD Protected by a Device if
With a Maximum Tripping Current of 30mA ( 411.3.3 (i) , Additional Protection

Knowing the Earth Loop Impedance , it is Possible to Calculate the Value of the Prospective Fault Current ( PFC )
At any Point in an Installation to Ensure that all Installed Protective Devices are of Adequate Rating to Clear the Potential Fault
Current Level ,
The Earth Loop Impedance Test Measures the Résistance of the Path that a Fault Current would take between Line / Protective Earth
this Must be Low Enough to Allow Sufficient to Flow to Trip a Circuit Protection Device ,

100mA / 300mA RCDs are Really Protection Against Fire rather than Shock ,

Residual Current Device shall have a Rated Residual Operating Current ( I∆n ) not Exceeding 30mA and an Operating Time Not
Exceeding 40mS at Residual Current of 5 ( I∆n )

As Provided by BS-4293 ,
BS-7071: 1992 ( Specification for Portable Residual Current Device , Safety Plug 13A- Tripping Current 30mA / 10mA Tripping Time ( 30mS ) IP 44

Old ↔ RCD BS-7288 Protected Switched Socket-Outlet ( SRCDs : 1992 ) Red / Black
SRCDs Specification , Rated Current 13A , Rated Trip Current 30mA , Trip Time 30mS

New ↔ BS-7288
Power Breaker 2G RCD , Metal-Clad , Trips 40mS at 30mA Double-Pole ( BS-7288 , BS-1363 , BS-4293 , Passive Operation
Cross-References BS-1362 ( Domestic , Cartridge Fuses , p-229 ( BS-1363 Class I Equipment / 3 / 5 / 13Amp , p-229

1G DP RCD , ( Metal Clad )
For Use in Industrial and Domestic , 13A max Load Trips at 30mA - BS-7288 / 200mS

Tested According to Specification BS-7071:1992 and BS-1363 British Standards Institution

BS-EN 61008-1
BS-EN 61008-1 : 2004
If this comes up ( Old BS-4293 Withdrawn ) ↔ Now RCCBs , Residual Current Operated Circuit-Breaker , Remains Current , ( 41.5

BS-EN 61009-1
BS-EN 61009-1 : 2004
If this comes up ( Old BS-4293 Withdrawn ) ↔ Now RCBOs , Residual Current Operated Circuit-Breaker , Remains Current , ( 41.3
If this comes up ( Old BS-3871 Withdrawn ) ↔ Now BS-EN 60898 MCBs , 2003 Remains Current , ( 41.3
If this comes up ( Old BS-4293 ( Replaced by BS-EN 61008-1 , look in the Regs ,

For The Apprentices ,
Am trying to make it Easy for you to Understand , Amberleaf ,

Domestic Electrical Installation Certificate
Is Not Intended to be Issued to Confirm the Completion of the Contract ,

This Certificate is a Declaration of Electrical Safety which should be Issued before an Installation is Put into Service ,
Domestic Electrical Installation Certificate
Is to be Used Only for the Initial Certification of a New Installation ,
New Work Associated with an Alteration or Addition to an Existing Installation , Carried Out in Accordance with BS-7671

Certificate May Only be Used where Every One of the Following Conditions Apply ,

The Electrical Installation Work Relates to a Single Dwelling ( House or Individual Flat )

The Design , Construction , and the Inspection & Testing of the Electrical Installation work has been the Responsibility of One Person
Or Organization ,

The Installation Forms Part of a ( TT ) ( TN-S ) ( TN-C-S / PME - Systems ,
Each of which falls within the Scope of the Domestic Electrical Installation Certificate

The Protective Measure for Fault Protection is Provided Primarily by Automatic Disconnection of Supply ( ADS ) 415.1.1
Earthing & Protective Bonding Arrangements if Necessary for the Protective Measure Applied for Safety ,
131.8 Alteration or Additions to an Installation ,

Installation Work Falling within the Scope of the Domestic Electrical Installation Certificate ,
Contractor will Invariably have Assumed the Role of the Designer ,

This Certificate is a Declaration of Electrical Safety which should be Issued before an Installation is Put into Service ,
Domestic Electrical Installation Certificate
Is to be Used Only for the Initial Certification of a New Installation ,
New Work Associated with an Alteration or Addition to an Existing Installation , Carried Out in Accordance with BS-7671

RCD Test Instrument , Operating Time in Milliseconds when Subjected to a Test Current Equal to the Operating Current I∆n

Insulation Résistance Enter the Measured Values of Line / Line ( Only Applicable for Multi-Phase Circuit(s)

Insulation Résistance Line / Neutral Line / Earth Neutral / Earth

“ Inspection of New Installation Work “
BS-7671 Requires that Every Installation , and Every Alteration or Addition to an Installation ,
Is Inspected During Erection and on Completion Before being put into Service to Verify so far as is Reasonable Practicable ,

Initial Verification
It is a Requirement of BS-7671 that the Relevant Design Information is Made Available to those Carrying Out the Inspection & Testing of New Installation Work ,
Irrespective of whether the Design was Carried Out by the Contractor or by Another Party ,
610.2
The Results of the Assessment of the Fundamental Principles Section 131 , the General Characteristics Required by
Section 311 / 313 , together with the Information Required by Regulation 514.9.1 shall be Made Available to the Person(s)
Carrying Out the Inspection & Testing ,

Inspection
Verify , Comply with Appropriate British / European or Equivalent Product Standards , 133.1.1 / 133.1.2
Been Correctly Selected and Erected , Not Visibly Damaged , Defective or Deteriorated such that Safety is Impaired
Suitable for the Environment in which they are Installed

Chapter 41 Protection Against Electric Shock
Basic Protection – Means of Protection Against Electric Shock Under Fault-Free Conditions ,
Fault Protection – Means of Protection Against Electric Shock Under Single Fault Conditions ,

“ Protective Measure “ BS-7671 Must Consist of
(i) An Appropriate Combination of a Provision for Basic Protection and an Independent Provision for Fault Protection ,
(ii) An Enhanced Protective Provision which Provides both Basic and Fault Protection

 

[amberleaf]

For the Apprentice ( this is all you need on BS-EN 61009-1 to help you understand something’s )
RCBOs BS-EN 61009-1 ( 41.3 )

● RCBOs ( Combined MCB / RCD ) Breaking Capacity ( kA ) BS-EN 61009-1 41.3
MCBs ( Breaking Capacity ( kA BS-EN 60898-1 ) 41.3

Devices are Intended to Protect People Against Indirect Contact ( Carelessness by Users )
Exposed Conductive Parts of the Installation being Connected to an Appropriate Earth Electrode and to Protect against Overcurrents
The Wiring Installations of Buildings and Similar Applications’ ,
May be Used to Provide Protection Against Fire-Hazards due to a Persistent Earth Fault Current ,

RCBOs
Having a Rated Residual Operating Current Not Exceeding ( 30mA ) 415.1.1
Also Used as a Means for Additional Protection in the Case of Failure of the Protective Means against Electric Shock ,

RCBO
6A / 30mA - 6kA type B
10A / 30mA - 6kA type B
16A / 30mA - 6kA type B
20A / 30mA - 6kA type B
25A / 30mA - 6kA type B
25A / 30mA - 6kA type B
32A / 30mA - 6kA type B
40A / 30mA - 6kA type B

RCBO
There are Important Differences when Using the Single-Pole RCBO most Commonly Used in the UK
( as Opposed to Two-Pole RCBOs Used in Europe )

With Single-Pole RCBOs Even when they have Tripped , the Neutral Wire is Not Interrupted so Operators may still Risk
Getting an Electric Shock ,

Two-Pole RCBOs Provide a Much Safer Solution as they Interrupt Both the Live & Neutral Wires ,

Primarily , the RCBO , a Residual Current Breaker with Overcurrent Protection , will Both Act as a Circuit-Breaker
And will Prevent Damage if there is an Overload Situation ,

For any Business or Operation , Safety is a Top Priority , a Two-Pole RCBO is the Circuit Breaker of Choice ,

Trip Current Settings , 30mA 100mA 300mA 500mA

Test Current Results
t∆ ½ I∆n RCBO Must Not Trip 0.5 / ½
t∆ x1 I∆n RCBO Must Trip Within 300mS ( BS-EN Only ←
t∆ x2 I∆n RCBO Must Trip Within 200mS ( BS- Only ←
t∆ x5 I∆n RCBO Must Trip Within 40mS 415.1.1

Harmonised Standards BS-EN 61008-1 / BS-EN 61009-1 ←
All the Device to Operate within 300mS at 100% I∆n

Previous Standards BS- 4293 has a Limit of 200mS ( When Testing )
x5 I∆n Remain Unchanged and are 40mS for all Standards ←

Regulations Appendix 3 table 3A RCD table p-243