- Reaction score
- 5,940
Sorry that you have had a temporary delay in passing. Do not give up yet.
Continuity of ring final circuit conductors:
Isolate power supply and prove dead, remove the conductors and measure the end to end resistance of each core giving you r1, rn and r2, check that the resistances are consistent i.e within r1 and rn nearly equal and r2 either equal with singles or 1.67 times higher with twin and earth, note down these results and add them to the schedule of test results for that circuit.
Calculate your expected values (r1+rn)/4 and (r1+r2)/4 for the figure eight measurements and note this down.
cross connect L and N and measure the resistance at each point of use in the circuit, make sure they are all the same and match (within 0.05Ω) the calculated value note down the measured value.
repeat the above for the L and cpc cross connection.
write down the measured value obtained in this last set of measurements as the R1+R2 of the circuit on the schedule of test results.
reinstate the circuit removing all cross connections.
move on to insulation resistance testing.
Earth fault loop impedance:
depends on whether it is external or for a circuit.
measurement of external EFLI should be done with the board off , main switch open and the main earth removed; measured and recorded and then the main earth reconnected. All dead tests should have been completed and recorded and recognised as complaint prior to starting live testing.
measurement for a circuit should be done only after all dead tests for all circuits are completed and correct. The main earth must be connected and also all bonding
conductors. The result should be recorded.
Even though I have been very brief, if you have done all that then you should have been OK.
Continuity of ring final circuit conductors:
Isolate power supply and prove dead, remove the conductors and measure the end to end resistance of each core giving you r1, rn and r2, check that the resistances are consistent i.e within r1 and rn nearly equal and r2 either equal with singles or 1.67 times higher with twin and earth, note down these results and add them to the schedule of test results for that circuit.
Calculate your expected values (r1+rn)/4 and (r1+r2)/4 for the figure eight measurements and note this down.
cross connect L and N and measure the resistance at each point of use in the circuit, make sure they are all the same and match (within 0.05Ω) the calculated value note down the measured value.
repeat the above for the L and cpc cross connection.
write down the measured value obtained in this last set of measurements as the R1+R2 of the circuit on the schedule of test results.
reinstate the circuit removing all cross connections.
move on to insulation resistance testing.
Earth fault loop impedance:
depends on whether it is external or for a circuit.
measurement of external EFLI should be done with the board off , main switch open and the main earth removed; measured and recorded and then the main earth reconnected. All dead tests should have been completed and recorded and recognised as complaint prior to starting live testing.
measurement for a circuit should be done only after all dead tests for all circuits are completed and correct. The main earth must be connected and also all bonding
conductors. The result should be recorded.
Even though I have been very brief, if you have done all that then you should have been OK.
