IR testing on power cables

[arashabb]

Good morning,
to carry out IR testing for armoured power cables in man panels ( pls see below image), do you remove the cable from circuit breakers on both ends or we can test them as it is?( by putting the probes on the cable lug or circuit breaker screw, depends the type of connection)

 

[MJPD29]

With all due respect, it is extremely concerning that you are undertaking this work and asking all these questions. If you do not have the knowledge to do the work tell your employer you need help, and if you have undertaken the work yourself I would seek help from a qualified spark immediately.

 

[Pete999]

With all due respect, it is extremely concerning that you are undertaking this work and asking all these questions. If you do not have the knowledge to do the work tell your employer you need help, and if you have undertaken the work yourself I would seek help from a qualified spark immediately.

Matthew the OP says he is a qualified Electrical Engineer

 

[pc1966]

You need to isolate the source (obviously!) and the load (but that is not always practical). If you have MCB/MCCB that are open totally with the trip mechanism "off" then it is simple to measure without disconnecting wires, better in fact as less change of introducing faults.

However, some RCD or RCBO are not isolated from the load when "off" and cannot be safely tested for all modes in such a case (as they still power the electronics). For RCD/RCBO without a "functional earth" wire, you can test them with L+N to E as you would do for loads that cannot be reasonably disconnected, such as LED lighting, etc. But if they have functional earth leads you really must disconnect the cable to safely and accurately test.