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Inspection & Testing Methods : City & Guilds 2392-10 fundamental Course
( Before : Test prior to the Installation being Energized )
Test – Sequence of Tests ,
( 1 ) Continuity of Bonding conductors and Protective conductors’ : Low reading ohmmeter
( 2 ) Continuity of Ring Final Circuit Conductors’ : Low reading ohmmeter
( 3 ) Insulation Resistance : 500V dc : 1.0m TN-C-S systems 0.4 s under 32A
• Instrument setting used for conducting insulation resistance Tests ( m ) C/G
( 4 ) ” Dead Test ” Polarity of each circuit : *** Low reading ohmmeter
• Which one of the following ” Dead Tests ” should also be repeated ” Live” ( Polarity ) C/G
“ After ” : Test Following Installation being Energized :
( 1 ) Earth fault loop impedance : ( Ze ) ( Zs )
( 2 ) Live polarity of Supply : ***
( 3 ) Prospective fault current : ( PFC ) ***
• PSCC : the expected current during a short-circuit fault the ( Prospective Short- Circuit Current ( PSCC ) C/G
( 4 ) Functional testing : ( RCD Testing )
• Which one of the following devices is Not designed to protect against Overload Currents C/G
• This is Designed to protect against Earth Leakage Currents Only ( RCD )
“Continuity of Bonding Conductors “
( 1 ) Safely isolate the Supply :
( 2 ) Disconnect one end of the Conductor , preferably the end at the Consumer unit :
( 3 ) ( Null out test Leads ) or ( Record and remember to Subtract from End Result )
( 4 ) Connect one test Lead at the Consumers units Disconnected end :
( 5 ) Connect the other test Lead to Metal work of which the Conductor you are Testing is Connected to
( Ensure any painted Metal work has been Scratched off , to make a Solid connection )
By not Connecting it to the Clamp will prove that the Integrity of that Clamp is Efficient enough / Correct BS-951 :
( 6 ) Test – the Result will give the Total resistance of the Conductor :
( Remembering to Subtract the Test Leads Resistance , if not Previously pulled out )
( 7 ) Re – Connect Bonding Conductor :
Documents :
( a ) Electricity at Work Regulations 1989 :
( b ) Health and Safety Executive Guidance Note GS38 :
( c ) BS7671 – Requirements for Electrical Installations :
Instruments
( Before : Test prior to the Installation energized )
( a ) Continuity of protective conductors – Low reading ohmmeter
( b ) Continuity ring final circuit – Low reading ohmmeter
( c ) Insulation resistance – Insulation resistance tester M
( d ) Live polarity – GS38 compliant voltmeter or test lamp
( e ) multi - probe test instrument : Earth electrode tester
Insulation Resistance 230V Installation : M
500V
250 dc 0.5 M
500 dc 1 M
RCD tests :
( a ) Earth loop impedance determines that an earth fault loop path exists ( Earth loop impedance tester )
( b ) Functional test determines that the RCD will actually operate in the event of a fault – electro-mechanical test using the ‘T’ button
( c ) Max test current for 100mA RCD is 100mA
IP Codes :
Intermediate barriers – IP2X or IPXXB
Horizontal top surfaces
( i ) Continuity and “ R2 “
( ii ) Earth fault loop impedance . ( Zs ) is the Measurement of the whole of the Fault path
Columns ( 6 ) and ( 7 ) of the Schedule of test Results page : 341
Require Measurements of ( R1 + R2 ) or R2 to be noted , may be simply a continuity test To ensure that the Line
and the Protective Conductors’ are Continuous ,
( R1 + R2 ) may also be recorded : ( Checking that the Earth Fault Loop Impedance is Sufficiently Low : and R2
: The requirements of the alternative method are met – see regs : page 243 ?
( Single phase TN-C-S installation has a Ze of 0.015 ohms. Calculate Prospective fault current :
Appendix 3 of BS7671 gives this relationship:
Uo
Zs = ------ where Uo = open circuit voltage at transformer , and is taken as 230 V
Ia
Uo 230
So the calculation is : Ia = ------ = -------- = 15333. kA ( 16 kA
Zs 0.015
( Before : Test prior to the Installation being Energized )
Test – Sequence of Tests ,
( 1 ) Continuity of Bonding conductors and Protective conductors’ : Low reading ohmmeter
( 2 ) Continuity of Ring Final Circuit Conductors’ : Low reading ohmmeter
( 3 ) Insulation Resistance : 500V dc : 1.0m TN-C-S systems 0.4 s under 32A
• Instrument setting used for conducting insulation resistance Tests ( m ) C/G
( 4 ) ” Dead Test ” Polarity of each circuit : *** Low reading ohmmeter
• Which one of the following ” Dead Tests ” should also be repeated ” Live” ( Polarity ) C/G
“ After ” : Test Following Installation being Energized :
( 1 ) Earth fault loop impedance : ( Ze ) ( Zs )
( 2 ) Live polarity of Supply : ***
( 3 ) Prospective fault current : ( PFC ) ***
• PSCC : the expected current during a short-circuit fault the ( Prospective Short- Circuit Current ( PSCC ) C/G
( 4 ) Functional testing : ( RCD Testing )
• Which one of the following devices is Not designed to protect against Overload Currents C/G
• This is Designed to protect against Earth Leakage Currents Only ( RCD )
“Continuity of Bonding Conductors “
( 1 ) Safely isolate the Supply :
( 2 ) Disconnect one end of the Conductor , preferably the end at the Consumer unit :
( 3 ) ( Null out test Leads ) or ( Record and remember to Subtract from End Result )
( 4 ) Connect one test Lead at the Consumers units Disconnected end :
( 5 ) Connect the other test Lead to Metal work of which the Conductor you are Testing is Connected to
( Ensure any painted Metal work has been Scratched off , to make a Solid connection )
By not Connecting it to the Clamp will prove that the Integrity of that Clamp is Efficient enough / Correct BS-951 :
( 6 ) Test – the Result will give the Total resistance of the Conductor :
( Remembering to Subtract the Test Leads Resistance , if not Previously pulled out )
( 7 ) Re – Connect Bonding Conductor :
Documents :
( a ) Electricity at Work Regulations 1989 :
( b ) Health and Safety Executive Guidance Note GS38 :
( c ) BS7671 – Requirements for Electrical Installations :
Instruments
( Before : Test prior to the Installation energized )
( a ) Continuity of protective conductors – Low reading ohmmeter
( b ) Continuity ring final circuit – Low reading ohmmeter
( c ) Insulation resistance – Insulation resistance tester M
( d ) Live polarity – GS38 compliant voltmeter or test lamp
( e ) multi - probe test instrument : Earth electrode tester
Insulation Resistance 230V Installation : M
500V
250 dc 0.5 M
500 dc 1 M
RCD tests :
( a ) Earth loop impedance determines that an earth fault loop path exists ( Earth loop impedance tester )
( b ) Functional test determines that the RCD will actually operate in the event of a fault – electro-mechanical test using the ‘T’ button
( c ) Max test current for 100mA RCD is 100mA
IP Codes :
Intermediate barriers – IP2X or IPXXB
Horizontal top surfaces
( i ) Continuity and “ R2 “
( ii ) Earth fault loop impedance . ( Zs ) is the Measurement of the whole of the Fault path
Columns ( 6 ) and ( 7 ) of the Schedule of test Results page : 341
Require Measurements of ( R1 + R2 ) or R2 to be noted , may be simply a continuity test To ensure that the Line
and the Protective Conductors’ are Continuous ,
( R1 + R2 ) may also be recorded : ( Checking that the Earth Fault Loop Impedance is Sufficiently Low : and R2
: The requirements of the alternative method are met – see regs : page 243 ?
( Single phase TN-C-S installation has a Ze of 0.015 ohms. Calculate Prospective fault current :
Appendix 3 of BS7671 gives this relationship:
Uo
Zs = ------ where Uo = open circuit voltage at transformer , and is taken as 230 V
Ia
Uo 230
So the calculation is : Ia = ------ = -------- = 15333. kA ( 16 kA
Zs 0.015
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