On initial verification of new installations I have been having a hard time with insulation resistance.
With RCBOs, fixed LED luminaires, intelligent dimmer controls and other sensitive equipment now the norm on almost all installations how do we overcome this and still carry out effective and compliant testing?
I have found it hard to test in the correct sequence. As to verify cpc via R1+R2 everything must be connected, and the removed again before testing IR. In my mind this seems to defeat the point. This is especially true on lighting circuits with intelligent dimmers and fixed LEDs.
I’m not sure of others workarounds/tips, but on these circuits I have taken to not connecting the LEDs/dimmers and wagoing all the connections at the switches and not cutting the bights of cable for downlights, then doing an R2 test at available points to prove cpc(which I don’t record later on paperwork). Then carrying out L-N L-E N-E IR testing. This in my mind then follows the sequence laid out in BS7671
I then install all the sensitive equipment and do my R1-R2 tests as normal (record these values) and then in place of full IR testing just a L+N-E to prove nothing I have just installed has caused any issues. Any one see any problems with this?
Aside from this, on full RCBO boards, I have been testing each circuit individually and calculating the whole board value. On small 6 way boards it works fine, however my tester only reads up to 2000Mohm, so on larger boards the value calculated is below 20Mohm, although in reality much higher. I note this on the paperwork. Anyone do anything different or have any other ideas?
With RCBOs, fixed LED luminaires, intelligent dimmer controls and other sensitive equipment now the norm on almost all installations how do we overcome this and still carry out effective and compliant testing?
I have found it hard to test in the correct sequence. As to verify cpc via R1+R2 everything must be connected, and the removed again before testing IR. In my mind this seems to defeat the point. This is especially true on lighting circuits with intelligent dimmers and fixed LEDs.
I’m not sure of others workarounds/tips, but on these circuits I have taken to not connecting the LEDs/dimmers and wagoing all the connections at the switches and not cutting the bights of cable for downlights, then doing an R2 test at available points to prove cpc(which I don’t record later on paperwork). Then carrying out L-N L-E N-E IR testing. This in my mind then follows the sequence laid out in BS7671
I then install all the sensitive equipment and do my R1-R2 tests as normal (record these values) and then in place of full IR testing just a L+N-E to prove nothing I have just installed has caused any issues. Any one see any problems with this?
Aside from this, on full RCBO boards, I have been testing each circuit individually and calculating the whole board value. On small 6 way boards it works fine, however my tester only reads up to 2000Mohm, so on larger boards the value calculated is below 20Mohm, although in reality much higher. I note this on the paperwork. Anyone do anything different or have any other ideas?
- TL;DR
- How to get round IR testing on modern circuits
