***Cont../ Useful Information for Electricians & Apprentices***

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O.S.G.. The use of other methods’ of determining Maximum Demand is Not Precludedwhere Specified by the Installation Designer

FirstlyI make no Apologies for the Way am Writing on any Matters . it can be a first day Apprentice or some one Needing aJog of Memory .
Sowe are all in the Same Boat . “ To Learn “

For the Apprentices . The Day we stop learning is the Day we hang Upour Tool-Bag

CookerDesign Current Calculations

Thefirst thing you have to do is get Your Head around the Calculations !!

(From a Design point of View ) 2392-10

DomesticInstallation Oven(s) & Hob(s) are to be Calculated upon their MAXIMUM LOADING
Startwith a simple Calculation ( An Oven has a rating of 2kW ) 2000

(I = P/V ) Formula … I = 2000 ÷ 230V = 8.70A …. Weare Using the Unit Amps


2392-10/ Domestic Installation Oven(s)

Ovenhas 4 Rings ( 2 x 1kW ) & ( 2 x 1.5kW ) & Grill ( 2kW ) & Oven (3kW )

-Controlled via a CookerSwitch with a Socket outlet .

Asa Designer . we’ll have to Apply Diversity ??

Important )- Diversity allowance to be Applied to the FULL LOAD CURRENT for CookingAppliances .

TheO.S.G. is telling us . Purpose of the Final Circuit fed from theConductors )
O.S.G.Table 1B p/97 – column (3) Cooking Appliances → At the Top of the Page Note : Type ofPremises ( 2392-10 → Household Installations ) Domestic Installation(s)

DomesticInstallation(s) Only O.S.G. - 10A + 30% f.l – Full Load ) of connected Cooking Appliances in the Excess of 10A+ 5A if a socket-outlet is incorporated in the Control Unit . ( C.C.U. ) – 45A + 13A Socket Switched with Neon .

Fromyour point of View ( The First 10A ofthe rated current plus 30% of the reminder ( Plus) 5A if the Control Unit incorporates s Socket.

Calculations)- You bank “ Hold OFF“ the first 10 Amps of the Maximum Load Current )
The10A will be used at the End of the Calculations’

-So your Work out the Total Power Rating & then calculate the Full Load Current

Calculations)- Power = ( 2 x 1 ) + ( 2 x 1.5 ) + ( 2+ 3 ) = 10kW

I= 10000 ÷ 230V = 43.48A … round it up to the first four numbers43.47826087 ( 48 ) 43.48A

UsingDiversity allowance stated ↑↑ ( 43.48A sub 10A = 33.48A )

I= 33.48 x 30 ÷ 100 = 10.04A

Youradding the ( 5A ) for Socket outlet . I = 10A + 10.04 + 5A = 25.04A )- Asa Designer this is your Expected Current Demand .

Remember )- Supply Cables Rated to suit DesignCurrent ( Iz )

 

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First Amendment : Definitions.p/29

Inspection : Examination ofan electrical installation using all the senses as appropriate . :leaving:

17[SUP]th[/SUP] Edition : Definitions p/25

Inspection : Examination ofan electrical installation using all the senses as appropriate .

 

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Inspection :- :yawn:

611.3. –
The inspection shall include at least thechecking of the following items where relevant . including as appropriate allparticular requirements for special installations or locations ( Part 7 )

611.3. –

The inspection shall include at least thechecking of the following items . where relevant to the installation and .where necessary . during erection .

 

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Just a reminder . 17[SUP]th[/SUP]& FirstAmendedment :13:

Testing - 2391-10 / 2392-10.

612.1.
Thetests of Regulations 612.2. to 6 . Whererelevant . shall be carried out in that order before the installation is [ ENERGIZED ] .
Wherethe installation [ INCORPORATES ] an earthelectrode . The test of Regulation 612.7. shall also be carried out before the [ INSTALLATION is ENERGIZED]

Ifany test indicates a failure to [ COMPLY ] thetest and any preceding test . The results of which may have been [ INFLUENCED ] by the fault indicated . shall berepeated after the fault has been rectified .

 

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BS-EN 61558-2-23:2001 :leaving:
Particular requirements for Transformers’ for construction sites .
Replaced by BS-EN 61558-2-23:2010 butremains current .

 

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Exampleof items requiring inspection for an ElectricalInstallation Condition Report ◄ :leaving:

A visualinspection should firstly be made of the external condition of all electrical equipment whichis not concealed
Furtherdetailed inspection . including partial dismantling of equipment as required .should be carried out as agreed with the person ordering the work ( 612.2. )

Theseexample are not exhaustive . numbers in brackers are Regulation references .

ElectricalIntake Equipment :
□ Servicecable .
□Service cut-out / fuse .
□Meter tails – Distributor .
□ Metertails – Consumer .
□Metering equipment .
□Isolator .

Whereinadequacies in distributor’s equipment are encountered . it is recommendedthat the person ordering the report informs the appropriate authority .

 

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Presence of Adequate Arrangements for Parallel or SwitchedAlternative Sources ( 551.6: 551.7 )

Automatic Disconnection of Supply . :13:
□ Main earthing / bonding arrangements ( 411.3 : Chap – 54 )

1) Presence of distributor’s earthing arrangement ( 542.1.2.1. :542.1.2.2. ) or
2) Adequacy of earthing conductor size ( 542.1.2.1 : 542.1.2.2. )or
3) Main protective earthing conductor connections ( 542.3.2.)
4) Accessibility of earthing conductor connections ( 543.3.2. )
5) Adequacy of main protective bonding conductor sizes ( 544.1. )
6) Main protective bonding conductor connections ( 543.3.2. :544.1.2. )
7) Accessibility of all protective bonding connections ( 543.3.2.)
8) Provision of earthing / bonding labels at all appropriate locations( 514.11. )

Other Methods of Protection .
( Where any of the methods listed below are Employed detailsshould be provided on separate sheets )

• Non-conducting location ( 418.2. )
• Earth-free local equipotential bonding ( 418.2. )
• Electrical separation ( Section 413: 418.3 )
• Double insulation ( Section 412 )
• Reinforced insulation (Section 412 )

 

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542.1.2. Supply Arrangements .

542.1.2.1.
ForTN-S system . means shall be providedfor the main earthing terminal of the installation to be connected to theearthed point of the source of energy . Part of the connection may be formed bythe distributor’s lines and equipment .

542.1.2.2.
TN-C-S system . where protective multiple earthingis provided . means shall be provided for the main earthing terminal of theinstallation to be connected by the distributor to the neutral of the source ofenergy .

542.1.2.3.
Fora TT or IT system . the main earthing terminal shall beconnected via an earthing conductor to an earth electrode complying withRegulation ( 542.2. )

542.1.2.4.
Wherethe supply to an installation is at high voltage . protection against faultsbetween the high voltage supply ans earth shall be provided in accordance withSection 442.

(542.2. ) Earthing Arrangements .

 

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ConditionReport Inspection Schedule for Domestic & Similar Premises with up to ( 100A ) Supply :waving:
Note:- This form is suitable for many types of smaller installation not exclusivelydomestic .

ConsumerUnit(s) - Distribution board(s)

4.1. Adequacy of working space / accessibility to Consumer Unit / Distribution board ( 132.12 : 513.1. ) [ Still the Same – 17[SUP]th[/SUP]Edition ]
4.2. Security of fixing (134.1.1. ) [ Still the Same – 17[SUP]th[/SUP]Edition ]
4.3. Condition of enclose(s) in term of ( IP ) rating etc ( 416.2. ) [ Still the Same– 17[SUP]th[/SUP] Edition ]
4.4. Condition of enclose(s) in term of ( Fire ) rating etc ( 526.5. ) [ Still the Same – 17[SUP]th[/SUP]Edition ]
4.5. Enclose not damaged / deteriorated so as to impair safety (621.2. (iii)) [ Still the Same – 17[SUP]th[/SUP] Edition ]
4.6. Presence of main linked switch ( as required by 537.1.4. ) [ Still the Same – 17[SUP]th[/SUP]Edition ]
4.7. Operation of main switch ( Functional check ) 612.13.2.
4.8. Manual operation of circuit-breakers and RCDs to provedisconnection ( 612.13.2. )
4.9. Correct identification of circuit details and protectivedevices ( 514.8.1. : 514.9.1. )
4.10. Presence of RCD quarterly test notice at or near Consumerunit / Distribution board ( 514.12.2. ) [ Still the Same – 17[SUP]th[/SUP]Edition ]
4.11. Presence of non-standard ( mixed ) cable colour warningnotice at or near Consumer unit / Distribution board ( 514.14. ) [ Still the Same – 17[SUP]th[/SUP]Edition ]
4.12. Presence of alternative supply warning notice at or near Consumerunit / Distribution board ( 514.15. )
4.13. Presence of other required labelling ( please specify ) –Section 514.
4.14. Examination of protective device(s) and base(s) : correcttype and rating ( no signs of unacceptable thermal damage . arcing oroverheating ( 421.1.3. ) [ Still the Same – 17[SUP]th[/SUP]Edition 421.3.]
4.15. Single-pole protective devices in line conductor only . (132.14.1 : 530.3.2. ) [ Still the Same – 17[SUP]th[/SUP]Edition ]
4.16. Protection against mechanical damage where cables enter Consumerunit / Distribution board ( 522.8.1. :522.8.11. – the same )
4.17. Protection against electromagnetic effects where cablesenter Consumer unit / Distribution board / Enclosures ( 521.5.1. ) [ Still the Same – 17[SUP]th[/SUP] Edition ]
4.18. RCD(s) provided for fault protection – includes RCBOs (411.4.9.: 411.5.2. – the same : 531.2. – the same )
4.19. RCD(s) provided for additional protection - includes RCBOs (411.3.3. : 415.1. - Still the Same )

OUTCOMES:- Acceptable condition ( Tick ) : Unacceptable condition State – C1 or C2 ) Improvementrecommended State – C3 ) Not Verified N/V ) Limitation LIM ) Not applicable N/A )

OUTCOME:- Use codes above . Provide additional comment where appropriate .
C1. C2 . & C3 . Coded items to be recorded in section K of the ConditionReport .
Furtherinvestigation required ? ( Y or N )

 

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612.13.2. Equipment . suchas switchgear and controlgear assemblies . drives . control and interlocks .shall be subjected to a functional test to show that it is properly mounted .adjusted and installed in accordance with the relevant requirements of theseRegulations .

612.13.2. Assemblies . suchas switchgear and controgear assemblies . drivers . controls and interlocks .shall be subjected to a functional test to show that they are properly mounted. adjusted and insalled in accordance with the relevant requirements of theseRegulations .

514.9.1. ) for simple installations the forgoing information maybe given in a schedule . A durable copy of the schedule relating to a distribution board shall be provided within oradjacent to each Distribution board

514.9.1. ) For simpleinstallations the foregoing information may be given in a schedule . A durablecopy of the schedule relating to a Distribution board shall be provided within or adjacent to each Distributionboard . Any symbol used shall comply with BS-EN 60617.

514.9.2. Any symbol used shall comply with IEC-60617.

( 514.8.1. ) [ Still the Same – 17[SUP]th[/SUP]Edition ]

( 514.15. ) Where aninstallation includes alternative or additional sources of supply . warningnotices shall be affixed at the following locations in the installation .
( 514.15. ) Where aninstallation includes a generating set which is used as an additional source ofsupply in parallel with another source . waring notices shall be affixed at thefollowing locations in the installation .

( 522.8.1 ) A wiring system shall be selected and erected to avoidduring installation . use or maintenance . damage to the sheath or insulationof the cables and their terminations . The use of any lubricants that can havea detrimental effect on the cable or wiring system are not permitted .
( 522.8.1 ) A wiring system shall be selected and erectedto avoid during installation . use or maintenance . damage to the sheath orinsulation of the cables and their terminations.

( 411.4.9.) . Where an RCD is used to satisfy the requirements’ of Regulation 411.3.2.2. the maximum values of earth faultloop impedance in table 41.5. may be applied for non-delayed RCDs to BS-EN 61008-1and BS-EN 61009-1 for a nominal voltage ( Uo of230V ) In such cases . an overcurrentprotective device shall provide protection against overload current and faultcurrent in accordance with Chapter 43 .

( 411.4.9.) Where an RCD isused to satisfy the requirements’ of Regulation 411.3.2.2. the maximum values of earth fault loop impedance in table41.5. may be applied for non-delayed RCDs to BS-EN61008-1 and BS-EN 61009-1for final circuits not exceeding 32A . In such cases . an overcurrentprotective device shall provide protection against overload current and faultcurrent in accordance with Chapter 43 .

( 411.3.3. ) An exception to (i) is permitted for :
a) socket-outlets for use under the supervision of skilled orinstructed persons . or .
b) A specific labelled or otherwise suitably indentifiedsocket-outlet provided for connection of a particular item of equipment .
( 411.3.3. ) An exception to (i) is permitted for :
a) socket-outlets for use under the supervision of skilled orinstructed persons . e.g. in some commercial industrial locations . or
b) A specific labelled or otherwise suitably indentifiedsocket-outlet provided for connection of a particular item of equipment .

Note 1 & Note 2 - Thesame . 17[SUP]th[/SUP] Edition .

 

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Symbols used in the Regulations resents3:

( Ze ) That part of the earth fault loop impedance whichis external to the installation ( Ω ) –313.1.
( Zs ) Earth fault loop impedance ( Ω ) – 411.4.5.
( R1 ) Résistance of lineconductor of a distribution or final circuit ( Ω ) – Appx 6 Schedule of test results .
( R2 ) Résistance ofcircuit protective conductor ( CPC ) of a distribution or final circuit ( Ω ) – Appx 6 Schedule of test results .

 

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ProtectionAgainst Overload Current . resents3:

433.1. Every circuit shall be designed so that a small overload oflong duration is Unlikely to Occur .
433.1. Every circuit shall be designed so that a smalloverload of long duration is Unlikely to Occur .

 

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433.1. Co-ordination between Conductor & Overload protective device.

 

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Fundamentalrequirement to understand the basic principles . Measured / Calculated resultsand what affect they have on a circuit .

 

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□ Listall the Relevant documentation that need to be Completed for this ElectricalInstallation Condition Report . :19:

- NewElectrical Installation / “ Meaning “ Initial Verification .
( InitialInspection Test & Verification )

Definitions’ - p/36 . FirstAmendedment .
Verification ) All measures by means of which compliance ofthe Electrical Installation with the relevant requirements of ( BS-7671 ) are checked . comprisingInspection . Testing & Certification .

“ Certification & Reporting “
- Electrical Installation Condition Report .
- Schedule ofInspections . ( 2392-10 ) for New Installation Work Only :- First Amendedment. Tells us .
- Condition ReportInspection Schedule ) :- for Domestic andsimilar premises with up to 100A Supply .

632 – Initial Verification :

632.1. Following the Initial Verification required by Chapter 61 . an ElectricalInstallation Certificate together with schedules of inspection and schedules oftest results . shall be given to the person ordering the work . These schedulesshall be based on models given in Appendix 6 .

632.2. The schedules of test results shall indentify every circuit. including its related protective device(s) and shall record the results ofthe appropriate tests and measurements detailed in Chapter 61 .

632.3. The person or persons responsible for the design .construction . inspection & testing of the installation shall . asappropriate . give to the person ordering the work a Certificate which takesaccount of their respective responsibilities for the safety of thatinstallation . together with the schedules described in Regulation 632.1.

632.4. Defects or omissions revealed during inspection &testing of the installation work covered by the Certificate shall be made goodbefore the Certificate is issued . -&-s

 

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□As an “ Inspector “ Existing Installation :19:
PeriodicInspection Report And Testing .

“ Certification & Reporting “
- ElectricalInstallation Certificate Report .
- Schedule of Inspections .
- Schedule of Test Results .

634 – Periodic Inspection & Testing .
634.1. Following the periodic inspection & testing describedin Chapter 62 . an Electrical Installation Certificate Report . together withschedules of inspection & schedules of test results . shall be given by theperson carrying out the inspection . or a person authorized to act on theirbehalf . to the person ordering the inspection . these schedules shall be basedon the models given in Appendix 6 . The schedule of test results shall recordthe results of the appropriate tests required of Chapter 61 .

634.2. Any damage . deterioration . defects . dangerous conditionsand non-compliance with the requirements of the regulations . which may giverise to danger . together with any significant limitations of the inspection& testing . including their reasons . shall be recorded .

621.5. Periodic inspection& testing shall be undertaken by a Competent Person .

Definitions’ - p/25 . FirstAmendedment .
Competent Person : Aperson who possesses sufficient technical knowledge . relevant practical skills& experience for the nature of the Electrcal Work Undertaken & is ableat all times to prevent danger and . where appropriate . injury to him /herself and others .

Inspection& Testing )- are Two different Words “ Meaning “

Definitions’ - p/36 . FirstAmendedment .
Testing ) Implementation of measuresto assess an Electrical Installation by means of which its effectiveness isproved . This includes ascertaining values by means of appropriate measuring instruments. where measured values are not detectable by Inspection .

Definitions’ - p/29 . FirstAmendedment .
Inspection ) Examination of an ElectricalInstallation using all the senses as appropriate .