So, as discussed in an earlier thread i've been doing some installation testing before swapping out my MCB's for RCBO's. In general, everything is testing out ok - though i did find one overheating crimp joint in one of my 16A heating radials that was put in by the spark who replaced my consumer unit way back when. Worth doing the testing just to catch that. dropped from 0.57 to 0.11 ohm when i remade that joint.
I have a question regarding my 16A hot water radial wired in singles.
IR testing is >200MOhm @ 250 and >500MOhm @500V on all cables - so all good there.
Continuity test results were:
L-N : 0.11
N-E : 1.7
L-E : 1.7
which would seem to indicate that the CPC has a high resistance. I need to double check the wire size, but from memory line conductors are 1.5mm; so i guess the CPC is 1mm. So far as i've been able to see there are no junctions in the CPC cable (unless there's one behind the MCB's / consumer unit mounting board). Readings were taken between the cables in the consumer unit and the end point of use.
Should i be concerned about the high CPC continuity reading ? it seems high to me. My estimate of the cable run is 5-6m. by way of comparison the end to end continuity of my final ring is 1.65Ohm and that's for ~ 20m
All tests were done using my Fluke 1653B, which is strictly speaking out of calibration, but i did buy a calibration reference block and continuity / IR readings were what they should be.
I have a question regarding my 16A hot water radial wired in singles.
IR testing is >200MOhm @ 250 and >500MOhm @500V on all cables - so all good there.
Continuity test results were:
L-N : 0.11
N-E : 1.7
L-E : 1.7
which would seem to indicate that the CPC has a high resistance. I need to double check the wire size, but from memory line conductors are 1.5mm; so i guess the CPC is 1mm. So far as i've been able to see there are no junctions in the CPC cable (unless there's one behind the MCB's / consumer unit mounting board). Readings were taken between the cables in the consumer unit and the end point of use.
Should i be concerned about the high CPC continuity reading ? it seems high to me. My estimate of the cable run is 5-6m. by way of comparison the end to end continuity of my final ring is 1.65Ohm and that's for ~ 20m
All tests were done using my Fluke 1653B, which is strictly speaking out of calibration, but i did buy a calibration reference block and continuity / IR readings were what they should be.