***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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Useful Junk .

Cable Reference :

CC – Bare copper sheathed .
MI - Cable .
V – PVC covered .
M – Low smoke & fume . ( LSF ) materialcovered .

L – Light duty ( 500V )
H – Heavy duty ( 750V )

Hence– a two-core 2.5mm[SUP]2 [/SUP] light duty ( MI ) cable with PVC oversheath would be ?? ( CCV –2L . 2.5 ) Next time look at your Pyro Cuter Tool ??

MineralInsulated copper sheathed ( MICS ) Cable . “ Fire Alarms“ :66:

 

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UsefulJunk .

RingFinal Circuit : OneSolution . :aureola:

i)To indentify breaks in the Ring FinalCircuit & Interconnections across the Ring .
ii)Test with a Low Reading Ohmmeter between each ( L . N . & E . Leg ) &the corresponding terminal at the nearest socket .
- A Low value indicates the short leg .
- A High vale the Long Leg .

► Reading at Mid-Point = 30m of 2.5mm[SUP]2[/SUP]+ 30m of 1.5mm[SUP]2 [/SUP]--- 2

=30 x 0.00741 + 30 x 0.0121 ÷ 2 = 0.293Ω
[ 30x 0.00741 + 30 x 0.0121 = 0.5853 )- ÷ 2= 0.293Ω ]

ThisValue is ( R1 + R2) Ring Final Circuit .

30m/ half of - 15m

 

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UsefulJunk .

MainIsolation . 100A

TheMain Intake position . Domestic Installation . Usually as part of the ConsumerUnit . 2392-10 (- The means to Isolate the Supply to whole Installation .
Thereis a requirement to Ensure that such Isolation beAccessible :aureola:

Tomany times I,e seen them under Stairs incupboards’ . Etc

 

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UsefulJunk .

MCBs – are designed tooperate at No more than ( 1.45 ) times their rating :aureola:

 

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►Part P – ( BR ) 2006 p/134 – Note/ 3 :19:

“ Garages “
Are considered to be Unsuitable for standard main frequencyfluorescent fittings due to ( ► Stroboscope Effects ◄ ) with rotating equipment .

[ Fluorescentlamp with ( High frequency electronic ballastsubstantially reduce this RISK . ]

 

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Inductive Loads .
Motors: Discharge lighting – Metal halide : Fluorescent or Neon:beatnik:

PartP /Building Regulation – p/15 – look in Chapter 10. 117 :19:

►The ABC,s of the BuildingRegulation . ( BR)

Part ( A ) “ Structure“ Where the positioning of ( Holes in a Joist ) Depths of chases in a masonry wallare affected .
Part( B ) “ Fire Safety “ Considers ( Smoke Alarm Systems ) & what must be done tomaintain any ( Fire Barriers ) That have been ( Breached during Work ) in a Dwelling .
Part( C ) “ Résistance to Passage of Moisture “ Looks at the ( Ingress of Moisture ) through a wall & therequirement to limit moisture build up .
Part( E ) “Résistance to Passage of Sound “ Oftenoverlooked when fitting equipment in ( Ceilings &Walls ) The sound barrier is to be maintained .
Part( F ) “ Ventilation “ Requirements for fitting of Ventilation in certain roomswithin a dwelling & the required amount of ( AirFlow ) -&-s. Big / Time ◄
Part( L ) - ( L1A & L1B ) “ Conservation of Fuel & Power . This covers both ►New& Existing dwellings ◄ for fitting orrecommending a certain amount of ( Low-energy light fixtures )

L1A / ► New Dwellings . L1B / ► Existing Dwellings .

Part( P ) – Electrical Safety ( P1 )
“Access to & use of Buildings “ Heights of Switches . Socket outlets &other equipment .

p/133. Part ( L ) – Fixed Internal Lighting . -&-s .
► One energy efficientlight fitting per four ( Fixed light fittings ) read Note[SUP]2[/SUP][SUP] [/SUP] below . Whichever is the Greater .
►one per 25m[SUP]2[/SUP] of floor area ( excluding garages ) Note[SUP]2 [/SUP]&Note[SUP]3 [/SUP]. Whichever isthe Greater .

Note[SUP]1 [/SUP].Note[SUP]2 [/SUP]. Note[SUP]3[/SUP]. p/134

 

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Rectification . in Wording . :43:

p/15- Building & Structures . with regards to SocketHeight as ( Part M ) sorry not Part P . Small Overpart on mySide .

TwoPart’s - Part / P . ( P1) “ Meaning “ Electrical Safety ( Firstly )

Part/ M . Heights of Switches. p.137 / 450mm . 1200mm

Kitchen Installation (- p/61

Rememberthat . in the ( BR) Kitchen is defined in the Building Regulations . as a room or part of a room ( -&- ) Specialinstallations . Special locations& Kitchens . p/59

( Not in Regulations BS-7671:2008 / Kitchen as Speciallocations )

 

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To Overcome Thermal Insulation Issues . 17[SUP]th[/SUP]Edition 2008 .
:beatnik:
Isi t permissible to design a Ring Final Circuit using 2.5mm[SUP]2[/SUP]cable protected by a ( 20A ) protective device .

( Yes ) if the effective CurrentCarrying Capacityof the cable is at Least ( 12.5 amp –20A x 20/32 ) So as to effectively have the same “ Deemed to comply status “
As regulation(s) give to ( 30A & 32A Ring Final Circuits )

 

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Useful Junk .
:19:

Youare Advised that it is ( Unlawful ) under the Electricity at Work Regulations 1989.

Towork on any Electrical Installation in the UK . unless you are a “ Competent Person “ ◄

TheElectricity at Work Regulations 1989 . requires persons to be Competent to prevent Danger& Injury . ( You will see this in the Regulations )
NoPerson should be Engaged in any work activity Unless . He or She possesses suchTechnical Knowledge or Experience . or is Supervised as appropriate for theWork .

TheMemorandum Qualifies Technical Knowledge or Experience as being .

i)Adequate knowledge or experience .
ii)Adequate experience of Electrical Work .
iii)Adequate Understanding of the system being worked on & practical experienceof that ( Class of System)
iv)Understanding of the Hazards that may arise during the work & thePrecautions . That . should be taken .
v)Ability to recognise at all times . whether it is Safe for Work to continue . Etc .

Useful Junk .
:19:

Copper isUsed for Underground Cabling in the transmission & Distribution Systems or (Where Weight is not an Issue ) right down toDomestic Supply ( Due to it’s LowResistivity )

 

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Firstly am NOT a Tutor . Amber .

I can offer some Guidance Only.

Amonly using this as One Example . Can you be Asked this on 2391-10 . Exams?? ( A /B ) :willy_nilly:

Explainthe Terms : 2391-10

a)Main Earthing Terminal .
b)Main Protective Bonding Conductor .
c)Exposed – Conductive – Part .

a)Main Earthing Terminal . 17[SUP]th[/SUP] Edition . p/26
TheTerminal or Bar providedfor the connection of ( Protective Conductors )including Protective Bonding Conductors . &conductors for ( Functional Earthing ) if any .to the Means of Earthing .

b) Main Protective Bonding Conductor . 17[SUP]th[/SUP]Edition . p/32
► Electrical Connection maintaining various ( Exposed Conductive Parts ) at Substantially the same Potential .

2391-10(- This involves joining together ( Metalwork )that is or may be Earthed so that it is atthe ( Same Potential) to prevent “ Danger “ Electrical Shock“ . frombetween those pieces of Metal as the Earth systemhandles a Fault .

c)Exposed Conductive Part : 17[SUP]th[/SUP] Edition. p/24
AConductive Part of equipment which can be Touched & which is NOT LIVE which can become Live when basicInsulation Fails .

17[SUP]th[/SUP]Edition . Conductive Part : of equipment which can be Touched & which is NOT LIVE which can become Live when basicInsulation Fails .

Refersto Items like :
TheMetallic Covers of electrical equipment which will normally be at Earth Potential . but which may develop a Voltage if the Fault Current goes through Equipment .

 

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The following errors occurredwith your submission :willy_nilly:

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The following errors occurredwith your submission :39:

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Part1 ) “ This is some thing I knocked up Amber . “ Wording comes in different Meaning on Exams . But they all work aroundthe same principle(s)

Firstly)- What is ( Zs) in Definition . Earth Fault LoopImpedance . ( Ω ) 41.3 – Maximum Earth Fault Loop Impedance .

2392-10.

Q)- A Prospective Earth Fault Current Test.
needsto be carried out on a Domestic Installation .Which has a Type “ B “ circuit breaker fitted .

State ( Which instrument(s) can be used . The testvoltage & current supplied by the Meter.
Whatequipment is likely to be fitted to the circuit .
State( the precautions needed to be takenprior to the test .
Describethe Test .

i)State ( Which instrument(s) can be used. The test voltage & current supplied by the Meter.

AProspective Earth Fault Current Test .
( PFC Tester ) – or Loop ImpedanceTester : with function ?
Thevoltage range the meter will work on it from ( 50Vto 500V ) which is taken form the Supply it is Plugged into .

Workon is from ( 50 V ) to ( 500V ) Which istaken from the supply plugged into .
Itmeasures the current between Line & Neutral across an Internal Impedance inside theTester . ( PFC ) = I = V/R = 230 / 0.5 =460A )
Yourmeter . will return a Value . 0A up to ≈ 50kA . ( 2392-10 – Youwill not use this Method in Initial Verification )

Asthe regulations say . ! Values can also be ascertained by (Calculation or Measurement ) “ Meaning “ Determined by other ways . 612.11

Thisis a Live Test . You may be measuring Live Energised Conductors ( Whenusing Clip-on Leads ) when -&-s are looking for . ?? Safety at all Times .

 

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Part2 ) Firstly : as Tester. 2391-10 & 2392-10. :39:

Secondly : Competent Person .



Competent Person . As this notthe first Live Test . ( PFC ) you WILL HAVE Informed persons . “ Meaning “

TheWhy’s . ►Warning Signs – Informing persons whocould be AFFECTED by “ LiveTesting “ ◄◄ This is what -&-s like to Hear .



What other Precautions Required. ?? Are you not the Person conducting the TEST. ◄◄ Yeah



1)Check the condition of the “ Test Instrument “& “ Probes / Leads

2)Check Test Leads & Probes conform to ( GN-38) ↔ full Title / HSE .

3)What –&-s . harp on about ?? Working with Live Terminals / Careful not to TOUCH any LIVE PARTS ( 17[SUP]th[/SUP]Edition 2008 )



MCB32A – BS-EN 60898



So. for the sake of the Regulations .

Youshould check your reading against the Time Current Graphs for relevant devicesto get an Actual Disconnection Time . 2391-10 ( 460A ) ?? 0.1 s / 5s



2392-10- You should check your Disconnection Time Table 41.1 ( TN-0.4 or TT-0.2 )



Example. ( PFC ) = I = V/R = 230 / 0.5 = 460A )

( 230V ÷ Ze / 0.28Ω= 821A )

( Ia ) /Operation of protective device within the time stated – Zs = Uo/Ia . 6A ÷ Current / 30A = 0.2s



TwoTests . Here . 612.11. ( PFC )



Prospective Short Circuit Current . …. Line & Neutral

Prospective Earth Fault Current . ….. Lineto Earth



Measurethe ( PFC ) at the Originof the Supply .

Etc. Check that the test instrument . Leads. Probes & Crocodile Clips . -&-s GN-38



►►►Check the Polarity Indictor ( if Any ) on the instrument for correct connection

Usingthe ( PFC ) Loop Tester set the selector switch to ( PFC ) & the range switch tothe highest setting ( test for PFC Value)



Youcan ( Reduce the Range switch to a Lower Setting ) to obtain a more AccurateValue .



Withthe . Megger 1552 / you have two settings . (PFC → No-Trip ) ( PFC → Loop– Hi )



Ifthe voltage measured at the time of test is 230V & the measured value ofFault Loop Impedance between Line & Neutral at the Originis ( 0.05Ω )

Maximumprospective Short – circuit = 230V / 0.05 = 4600A ( or 4.6 kA )



If( Ze ) is known & the Looptester does not have the facility to measure EarthFault Current .

Itcan also be Calculated by using the formula . ( Ipf ) = Uo / Ze .



p/35– Regulation . ( Ipf ) Prospective Fault Current .

p/36– Regulation . ( Uo ) Nominal Line to Earth voltage .

p/36– Regulation . (Ze ) External Earth Fault LoopImpedance .



3-Phase Installations the ( PFC ) recorded is Twice ( 2 x ) the Maximum SinglePhase Value Measured .

 

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InsulationRésistance . in your own words . Example. :6:

Example- Table 61 (- SELV = 50V/ A.C . to 250V /D.C.. ( V ) to ( MΩ ) ≥ 0.5 . (Mains to D.C. Current ) Remember . MinimumInsulation Résistance “ Wording “ . ≥ 0.5 - MΩ .

 

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RingFinal Circuit . Basics. :6:

Statethe effect on Conductor Résistance when Cables are Connected in Parallel .

Current in a Parallel Circuit.

Ohmslaw states that the Current is ( Inversely Proportionalto the Circuit Résistance ) Thisfact is True in Both ( Series ) & ( Parallel ) Circuits .

Thereis a Single Path for current in a ( Series )circuit .
Theamount of current is determined by the Total résistance of the circuit &the applied voltage . In a ( Parallel ) sourcecurrent divides among the Available Paths .

 

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Apprentices. :39:

Revision– Factors affecting Résistance .

Therelationship between the length of a conductor & its résistance is said tobe ( - Directly Proportional. / to its Length ( L )

Therelationship between the Cross-sectional Area of a conductor & its résistanceis said to be ??? Proportional.

• Thicknessof a Conductor . “ Cable “ Wire “

The Cross – sectional area of a conductor ( Affectsthe Résistance ) Thicker Wire provides ( Low Résistance) because they have more space for Electrons tomove .
Fevercollisions occur .

(Smaller )- Wire of the same substance ( Provides HigherRésistance ) because they Offer Less Space for to move around in .

► If you still get them in-&-s . How to remember . ( Proton is Positive ◄►You can remember that because they both start withthe Letter ( P )◄◄◄ Two / Ps

Proton = Positive . ( Two. P ) -&-s :6:
Neutrons= Neutral
Electrons= Negative .

 

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Extra Low Voltage . p/31

AnyVoltage in a Domestic Installation UP – TO ( 50V ) Thinkabout - SELVor PELV

SELV or PELV

ElectricalProduct may also be Indentified as a ( PELV ) - ProtectiveExtra – Low – Voltage . ( Low-Voltage but connectedto Earth ) watch this -&-s . :6:
SELV . Separated Extra – Low –Voltage. ( Low-Voltage but with Output Isolatedfrom the Input ) watchthis -&-s . :6:

 

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Apprentices)- some Testing matter to think about . Numbers . Yeah . :willy_nilly:

( R1 + R2 ) Testing – method( 1 )
( R2 ) Test - method ( 2 )

Testmethod ( 1 ) Continuity .
Testmethod ( 2 ) Continuity .

Zs = Ze + ( R1+ R2 ) Formula – Calculating – Earth – Loop – Impedance.

 

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Two/ Point HERE . 2391-10 . Do NotUse The Wording(s).

Multi – Function – Tester . ( MFT ) Ambers doing Handstands on this Matter . Give -&-s what they want to HEAR . Professionalism. Not a D.I.Y. er :89:

Thisgoes for you as well 2392-10 . Combined Instrument that can perform all the requiredTests ( Not a “ Part– P or 17[SUP]th[/SUP] Edition – Tester) ◄◄◄

►►Right Chaps . We keep this for On Site Only . “ Megger “ SlangTerm for an Insulation Résistance Tester .

 

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UsefulJunk .

Termedan “ Extraneous-Conductive-Part “
“ Water Pipe “ Not part of an Electrical System /Equipment . Froma Tester point of View .

P/27. Regulations / OverloadCurrent . An Overcurrent occurring in a circuit which is “ ElectricalSound “
Example– To much plugged into a KitchenRing ?? Washing machine / Tumble Dryer . Kettle . Toaster . T.V. :89:

2392-10 . PS. I can only give Guidance . Remember . as a Designer . The Kitchen Ring Final Circuit is always 100% / Maximum Demand . Yeah . Table1B . Colum 9 .
Point to Note : ( kW ) ◄◄◄◄ ► Real / Power . Yeah :89:

 

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Watchyour Wording here . Yeah ( LV) Regulation(s) . p/31 .

Low / Voltage :

AnyVoltage in a Domestic Installation . ABOVE - ( 50V ) → Band 11Circuits .

AnyWiring that carries ( Main Voltage ) → Band 11

 

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Certification& Reporting . 2392-10 . :6:

Minor Electrical InstallationWork Certificate . -&-s (- This is the documentthat must be Issued if an Existing Circuit is Worked On .

 

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ThePart P ( BR ) BuildingRegulations :smilewinkgrin:

Ineffect you have to .

Design ) The installation . soit is safe as it can be . ( P1 ) ElectricalSafety ( BR)
Install : The wiring &accessories to the standard of BS-7671 .
Inspect & Test : Your new work for compliance with BS-7671 .
Certificate : The work you havecompleted in compliance with BS-7671 .

Apprentices(- Ohm- Law . is the cornerstone ofelectrical calculations .

Referringto the Triangle ( Four Values ) V . I .R . & Z . – ( R or Z)

Symbol– ( V ) : Meaning – Electrical “ Pressure “ : Unit / Volt : Unit Abbreviation ( V ) :
Symbol– ( I ) : Meaning – Electrical “ Current “ : Unit / Amp : Unit Abbreviation ( A ) :
Symbol– ( R ) : Meaning – Electrical “ Résistance “ : Unit / Ohm : Unit Abbreviation ( Ω ):

Symbol– ( Z ) : Meaning – Electrical “ Impedance “ : Unit / Ohm : Unit Abbreviation ( Ω ):

Ifwe Compare an Electrical Circuit to a Garden Hosepipe .

•When you turn on the Water to the hose – The system will stabilise to a steadyflow .
•The pressure is constant & a set current is flowing .
•The flow is governed by the ( Bore ) résistanceor impedance of the pipes “ And “ the pressurepushing the water along .

Apprentices(- if you crimp the pipe . The waterwill slow down . This is because the résistance orimpedance of the pipes ( has just increased ) :- Therefore .
Toget the same current flowing again you have “ TwoChoices “

-Turn up the pressure to increase the FLOW
-Decrease the résistance / impedance by removing the “ Obstruction“ of the pipe .

Canyou work this as . More or Less the same with Electrical Circuit (s)

As I can not download Picture YET . am Working on it ?? Electrical -Drawing ◄

Wewill use ( R ) as you know it is the Symbol forelectrical résistance or loading . ( Scenario- Table Lamp at your bedside )

[V = 10V . I = 5A . R = Ω ] -→ > 5A -→ R = ?Ω ← 10V →. R = V/I – R = 10V ÷ 5A = 2Ω
[V = 100V . Z = 1000Ω . I = A ] -→ > I = ?A -→ 1000 = Ω ← 100V → . I =V/Z – I = 100 ÷ 1000 = 0.1A
[I = 100A . R = 1.0Ω . V = ?V ] -→ > 100A -→ 0.1Ω ← V =?V → . V = I x R - V = 100 x 0.1 = 10V

 

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Part( 1 )

Keepit Short for Understanding . :smilewinkgrin:

Firstly (- Themost important thing to remember . inany -&-s . ( ADS ) Automatic Disconnection of Supply . 17[SUP]th[/SUP] Edition 2008 . / Red Book – 415.1.1.
Thisis a primary method of protection from Electrical Shock .
-&-s point of View (- Insulation . Barriers . Earthing. MCBs. These four will stand you fast on (ADS ) RCDs . “ Testing “

Asyou are heading towards 2392-10 .

Earthing . Does a RCD need . “ Earthing “ . Important -&-s . What is the reason for EarthLoop Impedance . ?? Before we test any RCDs . ????? HINT / CPC
wouldan Earth Fault Loop Impedance test . ( Zs ) becomplete without an Earth / Polarity . ( Everything has aknock on effect ) for Testing .Yeah

Barriers . 2392-10 point ofview – 416.2.2. Top of ConsumerUnit ( CU ) IPXXD or IP4X . ( Shallbe possible ONLY by the USEof a key or TOOL “ Screwdriver“ +
Barriers . 2392-10 point ofview – 416.2.4. Side & Bottom of Consumer Unit ( CU ) or IPXXB or IP2X . ( Shallbe possible ONLY by the USEof a key or TOOL “ Screwdriver“ +

2392-10. IP – Rating : Arating given an “ Enclosure “ to describe its “ Résistance “ to ( Solids &Water Intrusion ) it is expressed in Numbers . IPX4 ??

Insulation . Insulation Resistance . ( IR ) They are not Crossed / Polarity . ? ( ifit is not . Initial Verification / Age / Wear& Tear on Cable(s)
Insulation . Where they are no breaks in the Cable(s)Dead-Short . ( Fit for its Extended Use )
Insulation . Can we use the Term ? Fault / Finding . Insulation Resistance .

MCBs . To ensure correctprotection form “ Overloads “ it is Importantthat the “ Protective Device - MCB “ operatingcurrent ( I[SUP]2[/SUP][SUP][/SUP]) is not bigger than ( 1.45 / times ) the current capacity of the Cable ( Iz ) The rating of the MCB - ( In ) MUST not beGreater THAN the CABLE carryingcapacity ( Iz )

Asfrom -&-s point of View - OperatingCurrent of the protective device is always larger THANits RATED VALUE .

2392-10point of view – 514.1.2. Installation of Cables . I canStress this Enough ◄► Identification & Notices . Thiswill bring out the Professional side ofyou . “ Tester “

( T ) As Far as is reasonably practicable . wiring hallbe so arranged or marked that it can be Indentified for – Inspection / Testing/ Repair or Alteration of the Installation .
(Can we say here . “ Maun Bonding Conductor has to be Identifiable “) If One has to Test it . would it safe Time / Money . ???

 

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Part( 2 )

AsDesigner in the Making :smilewinkgrin:

Regulation(- Chapter 521.3. p/97 ) Types of WiringSystem .
TheRegulations are giving you Examples . Yeah .

Table4A2 – gives Examples of installation methods of cables includingreference methods for obtaining Current-Carrying-Capacity whereit is considered that the same current-carrying-capacities can safely be Used .

TheRegulations always gives an Option 99.9% itis Not Implied that such Methods must be Employed or that Other Methods are Prohibited. Etc . Learning Curve


WhereExams are concerned . ( Earthing &Bonding are Two DifferentMeanings ) 2391-10 / 2392-10

Apprentices(- The regulations require the Earth to be HALF the SIZE of the Main CircuitConductor .

The- Whys . The Main Earthing Conductor . 543.1.3. States that where it is Desired Not toCalculate the minimum size of a Protective Conductor.
(Using the Adiabatic Equation ) Table 54.7 . p/130 . Should be Used -

2392-10- As you know The size of Mater Tails in Domestic Installation(s) is 25.0mm[SUP]2[/SUP] - Read this Carefully ◄
Table54.7 . Half the LineConductor size would be ( 12.5mm )

Froma Designers point of View – Manufactures do not produce this SIZE . So the next size UPwould be ( 16.0mm[SUP]2[/SUP] )

2392-10– Table 54.8 . p/134 . Minimum cross-sectional-area of the Main ProtectiveBonding Conductor .

Note : Local Distributors Networkconditions may Require a Larger Conductor . ( DNO )

Apprentices(- Continuity Testing – Test performedon a circuit to make sure the Earth Reachesthe End of it . Yeah .
Circuit-Protective-Conductor . ( CPC ) -&-s
Earthing-Conductor Regulation . p/32 .. This cable is the Last Path out of the Domestic Installation . for Fault / Current . itconnects the system Earth to the Main-Earthing-Terminal . ( MET ).
Main-Protective-Bonding-Conductor .Earth cable that is run to the Main/Incomer of any service to a DomesticInstallation . Usually – Gas . Water .

Fault Protection . ( ADS ) Regulations . 411 .
Thisis a System of putting in place a Protection against ElectricShock . in the Event of a Fault Situation. ( This takes us down many Paths . Yeah. for this matter ADS )

 

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“ Overcurrent ” a current flow in a circuit which is ( Greater ) than the ( Rated )current carrying capacity of the cables . :89:

Thiswould normally be due to a Fault on the Circuitor Incorrect Cable .

Ifa ( 20A ) cable protected by a ( 32A ) MCB was loaded by ( 25A) the cable would Overheat & the Device would continue to allow current to flow – This couldDamage the cable . ( Iz)

A Fault Current is a current which is flowing in acircuit due to a Fault ??

A Nail is driven through a cable causing an Earth Fault or a Short-Circuit Fault .
Thiswould cause a ( Very High Current to Flow ) through the circuit . Which must be( Interrupted ) before the Conductor reach a Temperature that could Damagethe Insulation or even the Conductor(s) .

 

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TTSystems .

FinalCircuits that are rated UP to & ( 32A ) require a maximum disconnection time of ( 0.2sec) 41.1.
Distributioncircuit require a maximum disconnection time of ( 1 second ) 411.3.2.4

Ihave not done any TT Systems yet . Am working onit . Amber . ( Youwill get this on 2392-10 ) thisis a start . Yeah :coolgleamA:

 

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Apprentices. → 411.3.2. 1. Final Circuits that are rated UPto & ( 32A ) Look First is it ?? TN- or TT ◄◄ :6:

Apprentices. Look in 41.1→ The Regulations are telling you . - requirea maximum disconnection time of ( 0.2sec ) TT :6:

 

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ElectricShock : ( Earthing comes into Exams a Lot )

Two– Ways in which we can be a risk .

i)Touching Live parts of equipment or system that are intended to be Live .
ii)Touching ( Conductive-parts) which are not meant to be Live . but havebecome Live due to a Fault . ( Basic Insulation Fails )

( Conductive-parts ) associatedwith the second of these can either be ( Metalwork )of Electrical Equipment & Accessories ( Class 1) & that of electrical wiring systems such as ( MetallicConduit ) & ( Trunking ) etc called (Exposed-Conductive-Parts )

orother ( Metalwork ) such as ( Pipes ) ( Radiators) ( Girders ) called ( Extraneous-Conductive-Parts )

17[SUP]TH[/SUP]Edition - P/24
( Extraneous-Conductive-Parts ) A ( Conductive-part) liable to introduce a potential . generally Earth Potential. & not Forming part of the ElectricalInstallation

( Extraneous-Conductive-Parts ) NOT ( Forming part of the Electrical Installation )

17[SUP]TH[/SUP]Edition – p/21
( Class 1 ) Equipment in which protection againstElectric Shock does NOT rely on Basic Insulation Only .

Butwhich includes means for the ( Connection of Exposed-Conductive-Parts ) to a ( ProtectiveConductor ) in the Fixed Wiring of the Installation . BS-EN 61140) :28:

 

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BS-EN 61140 ) Protection against Electric Shock . :28:
Commonaspects for Installation & Equipment requires That :-

• (Hazardous-Live-Parts ) . Shall not beAccessible .
• (Accessible-Conductive-Parts) Shall not be Hazardous-Live when there is ( No Fault or Under – Single FaultConditions )

BS-EN 61140 ) States that those ( ProtectiveMeasures ) providing protection under normal conditions ( That is . When no Faults Exits) provide Basic Protection & those ( Protective Measures ) giving protection Under Single Fault Conditions provide Fault protection– Sec 410 . refers

Themeasures of protection by ( Automatic Disconnection of Supply)

Regulations/ 410.3.3.
- DoubleInsulation .
- ReinforcedInsulation .
-Electrical Separation to Supply to Supply a Single Item of Equipment .
-Extra-Low-Voltage :- SELV . or . PELV . are generally applicable

2392-10. ( Automatic Disconnectionof Supply ) is the MostCommonly Employed method for Electrical Installation(s) .

 

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TheWhys .
- Double & ReinforcedInsulation are more frequently encountered in ( Items)
- Electrical Separation . SELV/ PELV . are only Applied to ( Specific Parts of an Installation)

- Basic/ Protection . ( Protective Earthing )
- Barriers. ( Main Protective Bonding Conductor )
- Enclosures. ( Automatic Disconnectionof Supply ) in the Eventof a Fault .
- Obstacles. ( Automatic Disconnectionof Supply ) for the PrimaryCircuit & connection of ( Exposed-Conductive-Parts ) ofthe Secondary Circuit connected to the ( Protective Conductor ) of the Primary-Circuit ofthe Source .

Point to NOTE : Fictional Extra Low Voltage ( FELV ) ◄◄◄ Equipment so supplied to ( TheProtective Conductor ) -&-s

WhereFictional Extra Low Voltage ( is Employed ) itis necessary to connect the ( Exposed-Conductive-Parts ) ofthe Equipment so supplied to ( The Protective Conductor ) of the Primary Circuit of the Sourcein addition to these Protective Measures required for ( ADS ) Regulation 411.7.3.

Whena Designer ( 2391-10) is considering the Use of ( Obstacles or Placing Out of Reach ) to provide Basic / Protection. it is strongly recommended that careful consideration be given to the ( Statutory Requirements ) relating to :-

• System. work activities & work equipment ( Regulation / 4. of the Electricity at Work Regulation 1989 )
•Insulation . Protection & Placing of Conductors ( Regulation / 7 . of the Electricity at Work Regulation 1989 )
•Work On or Near Live Conductors. ( Regulation / 14 . of the Electricity at WorkRegulation 1989 )
• Earthing . or other suitable precautions . (Regulation / 8 . of the Electricity at Work Regulation1989 )
•Working Space . Access & Lighting . ( Regulation / 15. of the Electricity at Work Regulation 1989 )
•Person to be “ Competent “ to prevent Danger& Injury . ( Regulation / 16 . of the Electricity at Work Regulation 1989 )

►►► Wording /NOT Act . ◄► But . Law . Exams ( Electricity at Work Regulation 1989 )

( Electricityat Work Regulation 1989 ) is ( law ) in the United Kingdom. ◄◄◄ in Exams / Wording is ( LAW )

ConsumerProtection is an ACT ◄◄◄ :75:

( Electricityat Work Regulation 1989 ) Applies to all ElectricalSystems at ( All Voltages )

 

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2391-10- Inspection & Testing: ( Remember two different Words ) Yeah. 2392-10

Inthe case of most Types Electrical Installation there is ( No Statutory Requirement ) to carry out ( Inspection & TestingPeriodically )

Itis . However . A Commonly adopted practice seen as a Means of Meeting the Maintenance“ Obligations “

The. Electricity at Work Regulations 1998. Regulation ( 4 ) & the Housing Act 1985 –Section 11 . BS-7671 is in the Most Part concerned with the Design .Installation . & Initial Inspection & Testing of New Installations

Chapter62 .
Containsa number of Requirements relating to ( Periodic Inspection & Testing ) . Regulation. 622.2. States that ( PeriodicInspection & Testing ) is not required an Effective Management SystemOperated by ( Skilled Persons ) covering itsMaintenance .

However. & as has been Mentioned Previously .
( The Person Responsibly may be Held Accountable in the Event ofan Incident Occurring )

(2391-10 ) Appropriate Records must be Keep of the Maintenance ActivitiesUndertaken . ( Cover ones But . Yeah ) :75:

 

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UsefulJunk .

Ambersof on One .

ImportTerms . that -&-s . will bring up in Exams .

Statutory& Non- Statutory Regulations .
Electrical Systems .
TheBuilding Regulations ( Part P )
Instruments .

2392-10. Firstly .
Foryour Assessor ?? are you aware of the Statutory& Non- Statutory Regulations that are relevant to InstallationWork

Tester. Example . Insulation Résistance.
i)The Range of Instrumentrequired . ≥ 0.5MΩ / 0.1MΩ .
ii)The Requirements regarding the Use & Performance of Test Equipment .

The more you put in the Easier it Becomes . :icon6:

 

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Asan Inspector . You have to consider the Implicationswhen carrying out an Inspection & Testing . ( Of an Installation ) :13:

Inspection& Testing . Certification Required .

InitialVerification .
PeriodicInspection & Testing .

( 2392-10 ) Initial Verification (- New Work & Alterations & Additions . ( TheCertification ( EIC ) Electrical InstallationCertification .
(2391-10 ) Periodic Inspection & Testing . for ExistingInstallations . ( TheCertification ( PIR ) Using Wording – Condition Report . ( PeriodicInspection Report)

►► Both must be accompanied by a ( Schedule of Test Results & Schedule ofInspections ) (EIC ) / ( PIR )

2392-10 – Exams . STATUTORY & NON- STATUTORY REGULATIONS .

Thestatutory regulations the apply to ( Electrical Work) 2392-10 / Initial Verification / NEW INSTALLATIONS . only

Let’skeep the Assessor . Happy . Yeah

TheHeath & Safety at Work . ( ACT ) ◄
TheElectricity at Work Regulation 1989 . ( Law )

2392-10.
The Building Regulation Part / P . ( Domestic Installation ) Yeah (This will guide you back to BS-7671 ) onMatters

BS-7671:2008/ British Standards . Non- Statutory Regulations. ( By using BS-7671 . You are complying with :- ( 2)
TheHeath & Safety at Work . 1974 ( ACT )
TheElectricity at Work Regulation 1989 . ( Law )

2392-10. ( As an Inspector ) -&-swill use the wording ( Inspector / You ) → → → → Not ( Tester ) Fail :grouphug:

 

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Amberof on One again .

ThisForum is here to HELP& Guide you on Matters .

Froman Exam point of View . 2391-10 . ( NotMeggers here )

( Electricityat Work Regulation 1989 ) Wording / Your Test Instrument / Sourceof Energy . Mains- Power / Battery ???

YourTest Instrument ?? Continuity Tester. is a Test on the System in itself . -&-s want to here . “ Continuity Tester “ Etc

2392-10/ Loop Impedance Tester . ( Live Test )

( Electricityat Work Regulation 1989 ) Which requiresan ( External Supply Source ) ≈ ≈ A.C. – becomes part of the System into whichit is Connected .


Point to Note . Here . Amber . :rockon:

Withoutany Thank You . I don’t know if am in the Right Direction . :43:

Pleasehit the ( Like Button ) it does help me OUT. PS. What’s a click on the Button. ( A Lot To Me )

 

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UsefulJunk .

Apprentices(- Earth Fault Current . ??

AnOvercurrent resulting from a ( Fault ) of ( Negligible Impedance ) between a Line Conductor & an ( Exposed-Conductive-Part ) or a ( ProtectiveConductor )

2392-10(- Protective Conductor Current ) “ Meaning “ ( Earth Leakage Current) Deleted / BS-7671:2008 ◄◄ :33:
Acurrent which flows to Earth . or ( Extraneous-Conductive-Parts ) in a circuit which is ( Electrically Sound )

Thiscurrent may have a ( Capacitive Component )including that resulting from the ( Deliberateuse of Capacitors )

17[SUP]th[/SUP]Edition . p/27 .
( Protective Conductor Current ) Electric current appearingin a ( ProtectiveConductor ) . Such as ( Leakage Current )or Electric current resulting from an ( InsulationFault . ) :19:

 

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UsefulJunk .

Tocomply with the Electricity at Work 1989 . & BS-7671:2008.

It is necessary . in appropriate circumstances . Toprovide means to “ Provide “ means to “ Prevent “ any equipment from being Inadvertently or unintentionallyEnergized .

Safe Isolation . ( Padlocking in the Isolated Position )

BS-7671:2008. No VoltageLimitations are Specified . Yeah :19:
Electricityat Work 1989 / Reinforces this ( Regulations apply to all System )

BS-7671:2008. 2392-10 – These are Designed toEncourage Good Practice . Yeah .

 

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Ihave Knocked something Up . in wording .to help you along the Way . Amber . :thinking2:

Thefollowing Test results . States what tests have been performed & which meter has been used .

( Ω) • Low-résistance ohmmeter / Continuitytester .
(MΩ ) • An Insulation résistance tester .
( Ω) • A Loop impedance tester .
(mA ) • A residual current device ( RCD ) tester …….. -&s / GN-3. ( Test instrument should not beoperated for longer than ( 2 seconds )
(kA ) • A prospective fault current ( PFC ) tester .
( Ω) • An earth electrode résistance tester .

• An approved test Lamp orvoltage indicator ……. GS-38
• A Proving Unit …….. ( Thisis an Optional item of Test equipment )

• Insulation Résistance test isthe correct term for this form of testing .

• Loop Impedance tester .
Thisinstrument functions by creating . in effect . an “ EarthFault “ for a brief moment . & is connected to the circuit via a Plug or by “ Flying Leads“ connected separately to Line . Neutral . & Earth.
( The instrument should only allow an Earth Fault to exist for a maximum of ( 40mS ) &resolution of ( 0.01Ω ) is adequate for circuitsup to ( 50A )

• PFC tester .
Normallyone half of a dual loop Impedance ( PFC ) tester . This instrument measures the prospective ( Line – Neutral FaultCurrent )
atthe point of measurement using the same leads as for ( LoopImpedance )

Shouldbe Banned (- “ NeonScrewdriver “ which encourages the passage of Current . at Low-voltage .Through the body .

Proving Unit :

Thisis an Optional item of Test equipment . in thatTest Lamps should be proved on a known Live Supplywhich could . of course be an “ Socket Outlet/ Lighting Point )

TestLamp on such A Known Live Supply may involve entry into “ Encloses “ with the AssociatedHazards

-&-s. Point to Note . TestLamps must be Proved against a ( Voltage Similar ) to that to be Tested . ( 230V.≈ . Lamp ) ??????

 

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BS-7671:2008. requirements .

AnElectrical InstallationCertificate can be issued only by the Installerresponsible for the Installation Work . BS-7671:2008

 

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UsefulJunk .

Asyou Know . Maximum Touch Voltage ( 50V )

TT/ Electrode of 100Ω & RCD of 300mA. What would the Touch Voltage Be???? 100 x 0.3 = 30V - Touch Voltage .