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

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“ 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]

Portable Appliance Testing - PATS

Examples of Bad Practice

No matter how well maintained you believe your electrical system to be there can be faults or unsafe areas that need correcting. Below are some of the more common problem areas.

Common Office Hazards

Incorrect Fuse Rating

Incorrect Polarity

Un-earthed appliances

Splits in cables

Trapped cables, between objects. (example: between desks and walls)

Trapped Cables (example; in floor boxes)

Overloading of sockets by 'piggy-backing' extension leads

Incorrect use of extension cables

Use of double adapters

Unsheathed pins on plugs

Un-earthed metal frame desks

Trailing leads

Water vessels near to electrical points

No access to sockets to disconnect in an emergency

Equipment such as fan heaters getting clogged and overheating

Dust clogging electrical equipment

Extension Leads

Extension leads are also considered as portable equipment and should be avoided where possible. If used, they should be tested as portable appliances. It is recommended that 3-core leads (including a protective earthing conductor) be used.

A standard 13 A 3-pin extension socket-outlet with a 2-core cable should never be used even if the appliance to be used is Class II, as it would not provide protection against electric shock if used at any time with an item of Class I equipment.

** Class I equipment is earthed and contains metal parts, e.g. storage heaters, washing machines
** Class II equipment is not earthed and is usually in a plastic case, e.g. hairdryers, fans

Guidance for Schools & Colleges

Headteachers and others responsible for the safety of pupils and staff need to ensure that electrical equipment is regularly maintained and electrical hazards are identified and dealt with promptly.

The Health and Safety at Work Act and The Electricity at Work Regulations cover the legal requirements for electrical safety and apply to all places for work, including educational establishments.

Under the Regulations, every employer has a duty to ensure that all reasonable precautions are taken to achieve electrical safety. In the case of schools and colleges, the headteacher will normally be regarded as the principal 'duty holder'. The principal duty holder is required to:

• ensure that installation, repair and maintenance work is only carried out by competent persons
• confirm the safety of equipment by arranging periodic inspection and testing and any necessary maintenance work
• implement and maintain safety procedures for all electrical equipment in use.

 

[amberleaf]

If adhesive tape is used , then it has been bicoloured : ( PEN )

* PEN ; conductors’ ( when insulated ) are either
Green & yellow : throughout their length . with blue markings at the terminations : or

Blue : throughout their length . with Green & yellow : markings at the terminations :

* Bare conductors’ are painted or identified by a coloured tape , sleeve or disk ,

 

[amberleaf]

Electrical Supply July 2009

a) Provision of supply
The supply into a hazardous area should be directly from a main switch isolator and not from a ring main feeding other parts of the site. The switch isolator must isolate all live and neutral conductors.

b) Type of Supply
The form of earthing defines the types of electrical supply used on a site.
* TT system, a system having one point of the source of energy directly earthed, the exposed-conductive-parts of the installation being connected to earth electrodes electrically independent of the earth electrodes of the source;
* TN system, a system having one or more points of the source of energy directly earthed, the exposed-conductive-parts of the installation being connected to that point by protective conductors;
* TN-C system, a system in which neutral and protective functions are combined in a single conductor throughout the system;
* TN-S system, a system having separate neutral and protective conductors thought the system;
* TN-C-S system, a system in which neutral and protective functions are combined in a single conductor in part of the system;
* IT system, a system having no direct connection between live parts and Earth, the exposed-conductive-parts of the electrical installation being earthed.

For new installations the electrical supplies into a hazardous area should be TT, although TN-S, may be acceptable.

TN-C-S (PME) may only be used on existing installations subject to an
appropriate, documented, risk assessment being carried out and that the
installation is subjected to regular checks on the current on the diverted neutral
current. For these installations it may be more practical to install a “derived TT
system” for the equipment in the potentially hazardous area.
b) Cable sizing
All electrical power cables must be designed and sized by a competent electrician/designer.
The design and cable sizing needs to take into account a variety of factors including:
* Length of the cable(s),
* Proposed method of installation (e.g. underground buried, underground in duct, above ground on trays),
* Type of load (motors, heaters)
* The maximum load, (most LPG pump motors, especially single phase, take a high starting current),
* Current

Information on cable design is available from tables in the 17th Edition Electrical Regulations ,

c) Voltage
Tests should be carried out installations to confirm there are no excessive voltage drops. (e.g. due to length of cable, connections from the incoming supply to contactors/cables, contactors/switches.) The voltage drop to the extremity of the circuit should not exceed 5%; more information in BS7671.

The available voltage at any motor should remain within the tolerances specified by the motor manufacturer both for start up and during running.

d) Protection against Electric Shock
When a different type of supply is used for the hazardous area compared with the supply to other parts of the site there must be a suitable separation, typically in excess of 2.5 metres, between un-insulated components to prevent
inadvertent contact between the two.

e) Site Earthing
Site earthing is required for all sizes of storage vessel, when the installation is fitted with electrical equipment, the primary requirement being protection against electric shock. This is not the same as the earthing required for the dissipation of static electricity; see
5 i). Earthing figures for bonding should meet those given in BS 7671.

An earth-bonding conductor should be run back to a primary earthing point at the source of energy. For a TN-S system this is where all metallic parts will ultimately be bonded.

The electrical supply must have a suitable effective earth. A “split” earth bar and test socket should be installed for each installation to allow testing of the earthing efficiency.

Bonding to other services must be connected to earth and comply with BS7671.

Notes:
• The armour of SWA cable should not be used as an earth conductor.
• Installations using cathodic protection systems for corrosion protection of vessels or pipework require special consideration and expert advice should be sought. the current rating of the type, the type of load (e.g. motor, heater etc), its short circuit capability and earthing impedance values, which need to be evaluated on site to ensure compliance with BS7671.

g) RCDs
Every power circuits into potentially hazardous areas should be protected by a Residual Current Device (RCD) being capable of disconnecting all poles including neutral of the circuit having a disconnection time of not more than 30ms.

h) Generators
Special precautions are required when a generator is to be used either during normal operations or more importantly in emergencies (see BS7671).

5. Installation of Equipment
a) Motor overload/low voltage protection

BS 7671 requires that every electric motor having a rating exceeding 0.37 kW be provided with control equipment incorporating means of protection against overload of the motor. Every motor needs to be provided with means to prevent automatic restarting after a stoppage due to a drop in voltage or failure of supply.

b) Cables
Cable conductors should only be of copper.
Power cables with integral mechanical protection are preferred, non-armoured cables can only be used providing the cable is protected by another method against mechanical damage.
Earthing cable sizes need to be assessed for each site prior to installation. 25mm2 should be adequate for most installations, should a smaller cable be considered then the appropriate calculations need to be carried out before installation.

c) Glands
Cable glands should be suitable for the relevant zone or area, the type of equipment being connected, the connection thread and for the cable being used. They should also maintain the Ingress Protection of the equipment.

d) Auxiliary equipment
Any auxiliary electrical equipment (e.g. solenoid valves) should be suitably protected (e.g. using an individual RCD) in the event of failure of the equipment. This protection should not be incorporated into hazardous area enclosures unless written approval is received from the manufacturer.

e) Enclosures of equipment for use in potentially Hazardous/Protected Areas
Any modification of the enclosures after dispatch from the manufacturer will invalidate the electrical certification for use in hazardous areas and must not be carried out.

f) Emergency Switch
A suitable switching device for emergency use should be fitted outside the potentially hazardous areas or separation distance (whichever is greater). When operated this would disconnect all electrical supplies (live and neutral conductors) to the associated equipment. It may be preferable to leave some auxiliary circuits live; e.g. lighting for the area, gas detection systems etc.

Except where failure to start after a brief interruption would be likely to cause greater danger; the installation should incorporate a system so that following the loss of power (e.g. power cut) power is not restored automatically but needs to be reset manually by an authorised person. This may be incorporated with the switching device in the above paragraph.

g) Isolation
Where required by BS7671 and BSEN60079–14 a means to secure the isolation in the off position shall be provided for the equipment in the potentially hazardous areas.

h) Switching off for mechanical maintenance
A means of switching off and isolating the power supply for mechanical maintenance should be provided for any electrical equipment in accordance with BS7671 and BSEN60079-14.

 

[amberleaf]

i) Earthing
Earthing arrangements should be assessed for each site prior to installation. Metallic sections of an installation should be designed, installed and tested to confirm they are electrically connected. For equipment not mounted on common
steelwork each component may need to be electrically connected, using an appropriately sized conductor, back to a single point.
The use of electrical connections across mechanical joints is not necessary providing, after installation, electrical conductivity is checked and confirmed to be acceptable. This should be checked periodically at intervals not exceeding 2 years.

Consideration should be given as to whether earthing of metallic items within a distance of 2.5 metres is also required. e.g. adjacent metallic fencing. Care should be taken to ensure that surface features (e.g. powder coating) do not render surfaces insulating.

For installation the incorporate Cathodic Protection systems suitable measures will need to be taken to ensure the parts of the installation protected by the CP system are not connected to the electrical system earth. Electrical isolators (with static build up protection) may need to be incorporated into the installation.

system are not connected to the electrical system earth. Electrical isolators (with static build up protection) may need to be incorporated into the installation.

j) Static earthing
Before connecting a vessel to a local earth rod an assessment is required to see if this would affect the protection of the total installation. It may be necessary to supply a separate “clean” earth for a delivery tanker earth connection.

k) Sodium lamps
Due to the potential hazard of ignition if a lamp is dropped or falls sodium lamps should not be installed within or above zone 0 or 1 areas. Before changing such lamps above zone 2 areas the area should be checked to confirm there is no flammable atmosphere present.

l) Redundant cables or cores
Any redundant cables/cores should either be removed or terminated in a suitable enclosure.

m) Multistrand cables
To prevent loose strands the terminations of these cables should be fitted with crimped or similar ends.

6. Testing/documentation
a) Initial inspection
All new installations and equipment should be subject to a detailed inspection as part of the commissioning, suitable documentation should be issued on satisfactory testing of the installation. Typical information is given in Appendix 1.
On completion DSEAR requires a register of the electrical components, their relevant zone of installation and the equipment approvals. Typical register layout is given in Appendix 2

b) Periodic Inspection
This is the routine inspection of all equipment, systems and installations and information is given in BS EN 60079-17. An assessment should be made, and recorded, at the time of issuing the initial inspection of:

˃The type of inspections required usually visual or close
˃ The period between inspections.

installations these are normally 12 months but must not exceed 3 years)

Visual and close inspections can be carried out without removing any covers or isolating the power.
The results of all inspections should be recorded.

c) Detailed inspection
In addition to any other periodic inspections a detailed inspection should be carried out at intervals to be determined by the competent electrician (usually not exceeding 5 years) or after any modifications to equipment and/or wiring. Modifications being defined as any change to the wiring, circuits or the replacement of items that are not identical to the one removed.

The next electrical survey will be due no later than ------------ 12 months from the
date of this document. ---------- (Delete as applicable.)
Signed: -------------- Name: ------------
Date: ----------
Qualification for hazardous area work: -------------------

This Schedule relates only to Certificate/Report Reference

Cable type :
A ) PVC/PVC cables
B ) PVC cables in metal conduit
C ) PVC cables in non-metal conduit
D ) PVC cables in metal trunking
E ) PVC cables in non-metal trunking
F ) PVC/SWA cables
G ) XLPE/SWA cables
H ) Mineral Insulated cables
Other ?
Extent covered by this schedule

Stripping out of Redundant Installation

1) All redundant installations shall be stripped out as far as practical. Where this exercise could lead to any future confusion labels shall be installed giving clear concise instructions.

2) Where the stripping out of redundant installation is specified, the work shall be carried out with the same care and attention as for a new installation, and the Contractor shall ensure that no damage to the building fabric or equipment ensues.

3) Under no circumstances shall the Contractor allow any of his own, or any other Contractor’s or Sub-Contractors operatives to disconnect or cut a live cable, or cut conduit / trunking containing ANY cables.

 

[amberleaf]

extract taken from wiring maters 2009

Conclusion
When carrying out additions or alterations to existing electrical installations, the reconfigured aspect of the electrical installation should comply with BS 7671:2008. The installer does not simply take responsibility for the newly installed or reconfigured element of the installation but all parts of the circuit(s) worked on - including the need to comment on the continued suitability or
otherwise of the equipment belonging to the distributor - this includes the condition of the metering equipment,
supply and meter-tails, distribution equipment and the earthing and bonding arrangements. If the client does not want to pay for
upgrades to existing equipment, this does not absolve the installer from responsibility, nor does a disclaimer.

 

[amberleaf]

Meter Operatives

* A minimum of 2 years experience in 3 phase and CT metering exchange works
* Preferably an NVQ or City and Guilds Qualification in a relevant electrical engineering subject
* Operatives must hold a valid certificate of authorisation from the relevant DNO (see note below re DNO accreditation)

* All operatives must hold a valid and current certificate for the following:
- First Aid
- Asbestos Awareness ( training provider )
- CSCS Card

* All operatives must attend a 2 day training course at the --------- Metering training centre – this training will be charged at £ --- per day per operative. At the end of the training, assessments will be carried out and only operatives who demonstrate the necessary level of competence will be authorised and certified to carry out
works on behalf of --------- Metering

* All staff engaged in operational metering activities must have a recently completed enhanced CRB check.

 

[amberleaf]

Building Regulations do state that structures built of combustible material ( i.e. a wooden shed ) must be at least 2 metres from the main house. ( Useful Junk )

local Building Control.
These rules DO apply to DIY activities, anyone carrying out DIY changes which are notifiable will have to submit a building notice to the local authority before starting work and pay the fee to have the work inspected and tested.

Problems may be encountered when trying to sell a property which has had notifiable electrical work carried out but for which the appropriate certificate cannot be produced.

PAT Test - Extension Leads

Extension Leads
Where extension leads are fitted with a standard 3 pin socket outlet these should be tested as Class1 appliances with the addition of a polarity check. Any such extension leads that are found to be without an earth wire should be marked as defective and removed from service.

The length of an extension lead should be checked to ensure that it is not so great that the appliance performance may be affected by voltage drop. Additionally, the length should not exceed the following:

core area maximum length
1.25mm2 12 metres
1.5mm2 15 metres
2.5mm2 25 metres

2.5mm2 extension leads are too large for standard 13A plugs, although they may be used with BS EN 60309 industrial plugs. Extension leads exceeding the above lengths should be fitted with a 30mA RCD manufactured to BS 7071.

Cable reels must be used within their reeled or unreeled ratings as appropriate.

PAT Test Reasons
1).Faulty electrical appliances and leads are the main cause of accidental fires in commercial buildings, representing over a quarter of all such fires.
2) It is your legal responsibility as an employer to provide a safe working environment
3) The majority of insurance companies now make it a stipulation of your insurance cover.

Portable Appliance Testing
( PAT Testing )
PAT Testing Legislation
The legislation of specific relevance to electrical maintenance is the:

* Health & Safety at Work Act 1974
The Health & Safety at Work Act 1974 is the basis of all Health and Safety Legislation in the UK. The law is all encompassing and sets out the general obligations that:
a. Employers have towards their employees and members of the public and
b .Employers have for themselves, each other and members of the public.
The law requires that an assessment of risk is made and that reasonably practicable measures are put in place to minimise any risk.

It is clear that the law sets out the general guidelines regarding safety.

* Management of Health & Safety at Work Regulations 1999
The Management of Health & Safety at Work Regulations 1999 state:
"Every employer shall make suitable and sufficient assessment of:
(a) the risks to the health and safety of his employees to which they are exposed whilst at work, and
(b) the risks to ensure the health and safety of persons not in his employment arising out of or inconnection with the conduct by him or his undertaking."
Again it is clear that an assessment of risk has to made and reasonably practicable steps taken to minimise such risk.

* Electricity at Work Regulations 1989
The Electricity at Work Regulations 1989 state:
“All systems shall at all times be of such construction as to prevent, so far as reasonably practicable, such danger."
"As may be necessary to prevent danger, all systems shall be maintained so as to prevent, so far as reasonably practicable, such danger."
“ System” means an electrical system in which all the electrical equipment is, or may be, electrically connected to a common source of electrical energy and includes such source and such equipment
“ Electrical Equipment” includes anything used, intended to be used or installed for use, to generate, provide, transmit, transform, rectify, convert, conduct, distribute, control, store, measure or use electrical energy."

It is clear that these regulations require a regime of testing and inspection to maintain portable appliances in a safe condition.

* Provision and Use of Work Equipment Regulations 1998 ( PUWER )
PAT Testing Legislation - The Provision and Use of Work Equipment Regulations (PUWER)
The Provision and Use of Work Equipment Regulations
1998 state:
“Every employer shall ensure that work equipment is so constructed or adapted as to be suitable for which it is provided."
The PUWER 1998 covers most risks that can result from using work equipment. With respect to risks from electricity, compliance with the -Electricity at Work Regulations 1989 is likely to achieve compliance with the PUWER 1998.
- PUWER 1998 only applies to work equipment used by workers at work. This includes all work equipment (fixed, transportable or portable) connected to a source of electrical energy.
- PUWER does not apply to fixed installations in a building. The electrical safety of these installations is dealt with only by the Electricity at Work Regulations

* Workplace (Health, Safety and Welfare) Regulations 1992
Scope of the legislation.
It is clear that the combination of the HSW Act 1974, the PUWER 1998 and the EAW Regulations 1989 apply to all electrical equipment used in, or associated with, places of work. The scope extends from distribution systems down to the smallest piece of electrical equipment. It is clear that there is a requirement to inspect and test all types of electrical equipment in all work situations.

The Electricity at Work regulations states that:
"No person shall be engaged in any work activity where technical knowledge or experience is necessary to prevent danger, or where appropriate, injury, unless he possesses such knowledge or experience, or is under such degree of supervision as may be appropriate having regard to the nature of the work".

The IEE Code of Practice states:
those carrying out the inspection and testing must be competent to undertake the inspection and, where appropriate, testing of electrical equipment and appliances having due regard of their own safety and that of others. What should be considered is that the 'danger' to be prevented, includes not just the dangers which may arise during the testing procedure to the tester and others, but also the dangers which may arise at a later date as a result of using equipment which has not been effectively tested.

The tester must have an understanding of the modes of electrical, mechanical or thermal damage to electrical equipment and appliances and their flexes which may be encountered in any environment.

Training must include the identification of equipment and appliance types to determine the test procedures and frequency of inspection and testing. Persons testing must be familiar with the test instruments used and in particular their limitations and restrictions so as to achieve repeatable results without damaging the equipment or the appliance

PAT Test Equipment Types
There are many European standards and guidance notes regarding portable appliances and equipment, though they do not establish a common and specific definition of such equipment. Even so, there does seem to be a consensus of opinion that such equipment is either hand held whilst being connected to the supply, or is intended to be moved whilst connected to the supply, or is capable of being moved without undue difficulty whilst connected to the supply.

It is usual for this equipment to be connected to the supply via a plug and socket, however this is not a requirement for electrical equipment to be deemed portable or transportable. It is common to define a portable appliance by saying that it is 'anything with a plug top on the end of it'. This is a mistake as it may mean that there are some appliances in the system that are never tested.

The IEE Code of Practice gives guidance on the various equipment types:

Portable appliance
An appliance of less than 18kg in mass that is intended to be moved whilst in operation or an appliance which can easily be moved from one place to another, e.g. vacuum cleaner, toaster, food mixer, etc.
Movable equipment (transportable)
This equipment is either:
18 kg or less in mass and not fixed, e.g. electric fire. or
Equipment with wheels, castors or other means to facilitate movement by the operator as required to perform its intended use, e.g. air conditioning unit

Hand Held equipment or appliances
This is portable equipment intended to be held in the hand during normal use, e.g. hair dryer.

Stationary equipment or appliances
This equipment has a mass exceeding 18kg and is not provided with a carrying handle, e.g. refrigerator

Fixed Equipment/appliances
This equipment or an appliance which is fastened to a support or otherwise secured in a specific location, e.g. bathroom heater

Appliances/equipment for building in
This equipment is intended to be installed in a prepared recess such as a cupboard or similar. In general, equipment for building in does not have exposure on all sides because one or more of the sides, additional protection against electrical shock is provided by the surroundings, e.g. built in electric cooker

Information technology equipment
Information technology equipment includes electrical business equipment such as computers and mains powered telecommunications equipment, and other equipment for general business use, such as mail processing machines, VDU's photo-copiers

 

[amberleaf]

Safe work practices - Managing electrical safety in the workplace
Employers must carry out a risk assessment to identify potential workplace electrical hazards and to access the likelihood of injuries from the exposure to these hazards. This will enable appropriate control measures to be implemented.

General precautions - Always ensure that:
An accessible and clearly identified switch near each fixed machine to cut off power in emergency is provided.
For portable equipment, socket-outlets are close by so that equipment can be easily disconnected in an emergency.
Electrical equipment used in flammable/explosive atmospheres should be designed to stop it from causing ignition.
Double adaptors and 'piggy back plugs' are not used.
The wattage of all bulbs in light fixtures and lamps are checked to make sure they are the correct wattage. Replace bulbs that have a higher wattage than recommended to prevent overheating that could lead to a fire.
Lightbulbs and other equipment which could easily be damaged in use are protected. There is a risk of electric shock if they are broken.
Suspect or faulty equipment is taken out of use, labelled 'DO NOT USE' and kept secure until examined by a competent person.
Where possible, tools and power socket-outlets should be switched off before plugging in or unplugging.
Equipment is switched off and/or unplugged before cleaning or making adjustments.
There is provision for all equipment to be stored carefully, securely and safely.
Workers using electrical equipment are trained and supervised.
Electrical installations are safe eg, by providing enough power outlets.
Worn or frayed cords are replaced.
Leads, wiring and cables are in good condition and in the correct position.
PVC insulation tape should not be used to repair damaged cords. Have the cords replaced.
Machinery is unplugged before cleaning.
Enough socket outlets are providing – overloading socket outlets by using adaptors can cause fires.
All connections to power points are made using the correct plugs.
Isolating transformers and residual current devices (RCD) are used.
The electricity supply is isolated from earth and has a voltage between conductors not exceeding 230 volts.
No part of a crane, digger, excavator, drill rig or other mechanical plant, structure or scaffold is brought closer than 4 metres to an overhead line without the written consent of the powerline owner.
Equipment suitable for the working environment is used, eg, cordless tools for wet and damp conditions.
Electric risks can sometimes be eliminated by using air, hydraulic or hand-powered tools.
The main board is locked and the switches are safe and identified.

Suggested testing intervals for portable RCD's
Testing of non-portable RCDs on switchboards or inbuilt into socket outlets must be carried out on a regular basis. This includes both push button testing by the user and inspection testing for operation by an electrician. Unless operated from time to time, an RCD may "mechanically freeze" and not trip when required.
Push-button testing by the user only confirms satisfactory mechanical performance of the tripping mechanism of the RCD. It does not replace inspection testing for operation by a licensed electrical worker.
As non-portable RCDs are far less susceptible to damage than portable RCDs, they are not subjected to the same testing and inspection procedures.In the case of non-portable RCDs, push button testing is recommended at three monthly intervals.

After tripping out, an RCD must be re-activated only when the cause of the trip has been established and remedial action taken.
( Hire equipment : Push-button test (by user) Before each hire . Test for operation By an Electrician )

With some loads it is normal to use a slightly higher rated fuse than the normal operating current. For example on 500 W halogen floodlights it is normal to use a 5 A fuse even though a 3 A would carry the normal operating current. This is because halogen lights draw a significant surge of current at switch on as their cold resistance is far lower than their resistance at operating temperature.

Preliminary Inspection : Pat – Testing ( Disconnection ) Determine whether the equipment can be disconnected from the supply and disconnect if, and only if, permission is received. If permission is not received to disconnect the supply do not proceed with any tests and record that the equipment has not been inspected and label accordingly ←←←

Pat – Testing : Should then be performed and the Code :
Recommends that Three Tests are made; Earth Continuity, Insulation Resistance and Functionality. ←←←

 

[brucelee]

great work mr amberleaf,
i have read all this post and found it very useful as i am doing a 2391 course at the minute and its been a great help thanks

 

[amberleaf]

Can some one explain to me what is meant in this context by "The Origin of the Installation"?

Regs : p/27
Origin of an installation . The position at which electrical energy is >>> delivered to an electrical installation

 

[Phil]

guy`s please don`t post on here if you would like to show your appreciation please just hit the thank you button, if you have any questions feel free to copy part of ambers post and drop into the relevant section for help. try to keep this thread clear so it`s easier to read for everyone

 

[adamwilliams]

It's quite an useful information, but I think one should keep the things short and simple

 

[amberleaf]

Thank you adamwilliams . Life does not Work that way for Electricians’ PS. this Forum has Helped many Electricains to Get there -&-s . let me put it this Way . Please . short and simple
you have to have an Understanding Big Time . we are Working up to the Level of 2392-10 / 2391-10 . thank you Amber

Useful Information for Apprentices***
Section - 301- Questions - Testing ,

 

[amberleaf]

Re: PIR reporting and competent persons.

3. Selection and erection in relation to maintainability, including cleaning

Section 529 of BS 7671 deals with the selection and erection of electrical equipment in relation to maintainability of an electrical installation, including cleaning of such equipment, and requires, amongst other things, that provisions are made for the safe and adequate access to all parts of the wiring system which may require maintenance.

All electrical equipment and materials used in an electrical installation should be selected and erected so as to be fit for purpose, suitable for their environment and serviceable throughout the lifetime of the installation.

Regulation 529.2 requires that where any protective measure such as a barrier or enclosure must be removed or opened in order to carry out maintenance, reinstatement of the protective measure should be practicable without reducing the original degree of protection.

Electrical equipment such as isolators, distribution boards, consumer units and other similar enclosures containing controlgear should, wherever practicable, be readily accessible, ideally from floor level (Regulation 513.1 refers).

Luminaires which will require removal for replacing lamps or for cleaning and the like, particularly where fluorescent fittings are involved, should preferably be fitted with a suitable luminaire supporting coupler (LSC) or a suitable plug and socket-outlet arrangement. Such provisions are likely to result in a safer method of working when replacing lamps, and facilitate the cleaning of luminaires by unskilled persons without giving rise to danger. Where luminaires are installed at high level, consideration should be given to providing hoisting facilities so maintenance can be carried out at ground level, or by providing means of access via a suitable mobile elevated working platform† (MEWP).

4. Periodic maintenance

Chapter 62 of BS 7671 deals with the requirements for periodic inspection and testing of an electrical installation. Where required, periodic inspection and testing should be carried out to determine whether the installation is in a satisfactory condition and safe for continued use (Regulation 621.1 refers).

It is therefore essential that the wiring system and electrical equipment are so arranged that adequate access to electrical equipment and the wiring system is maintained at all times to facilitate inspection, testing, maintenance and repair (Regulation 132.12 refers).

4.1 Records of maintenance

Records of maintenance, including test results, preferably kept throughout the working life of an electrical installation, will enable the condition of the electrical equipment and maintenance systems to be monitored. Without effective monitoring, duty holders cannot be certain that the requirement for electrical installations to be ‘adequately maintained’ has been complied with (refer item 2).

4.2 Operation and Maintenance (O & M) manuals

Every electrical installation in a place of work should be provided with an Operation and Maintenance (O & M) manual# to enable the user and person responsible for maintenance to discharge their responsibilities under the Health and Safety at Work Act 1974, paragraph 6. Such a manual, for example, may include:

● the installation design specification .
● the as-installed drawings .
● the Electrical Installation Certificate .
● the recommended periodic inspection and test intervals for the installation (including where necessary, different parts of installations) .
● a maintenance schedule for all installed electrical equipment (including the necessary personnel competency requirements) .
● manufacturers technical specifications, including recommended maintenance procedures and intervals .
● safe systems of work and safe isolation procedures .
● all special instructions for the operation and maintenance of equipment, such as access arrangements or powering-down and start-up procedures.

*HSE booklet HSR25 Memorandum of guidance on the Electricity at Work Regulations 1989 does not define the term ‘Duty Holder’ but a duty holder in respect to the EWR is widely accepted as being a person who has overall responsibility for the maintenance, safety and quality of the electrical installation and electrical equipment. In some exceptional circumstances, an employee may be assumed to be the duty holder (HSR25 guidance to regulation 3(2)b refers).

† Any person using a mobile elevated working platform (MEWP) must be suitably and adequately trained and authorized to operate it.

# Further information on what should be contained in an O & M manual can be found in BS 4884 Technical Manuals, BS 4899 Guide to user’s requirements for technical manuals and in CIBSE Guide to ownership, operation and maintenance of building services.

PS. Feel free to move it . to the Right Place . ***

 

[Dan]

I'm just bumping some of the older threads in the general electrical forum that had a lot of replies. They might not be current topics, if they're not, just ignore them and they'll soon drop off the list. If you DO wish to add a reply and get the conversation going again, feel free to do so. Your input might help somebody else in the future.