HELP PLEASE

[Lurch]

When you go round customers house to quote for board change I have heard people say to do a neutral to earth ir test to ensure the new rcd will hold. Do you have to go round unplugging everything before you do this test? Thanks

As it's not an approved test as such, do whatever you want. If it passes with everything plugged in great, if not maybe unplug things and see if it improves, entirely up to you. If it's going to trip with everything plugged in then are you going to just shrug it off and walk away when the RCD keeps popping? Use a bit of judgement and professionalism to assess what should be done.

Also, personally I'd do both live conductors to earth, leakage is leakage, regardless of what colour the wire is.

 

[batty]

Put RCBO's in lot less chance of having problems. I allow for this in my quotes if people don't want to pay I don't do the job. When you have 20 to 40 year old wiring putting it through one or two RCD's is asking for trouble. Even on new stuff I RCBO it allow for it in pricing jobs a goodun.

 

[initforthemoney]

I only ever test N-E, as thats where most of the hidden faults lie.

Its very unusual to have earth leakage L-E.

 

[Andy™]

When you go round customers house to quote for board change I have heard people say to do a neutral to earth ir test to ensure the new rcd will hold. Do you have to go round unplugging everything before you do this test? Thanks

neutral to earth can be just as bad as live - neutral. if you have a L-E fault, and IR N-E, you can have 500v between live & neutral depending on resistance of fault, and resistance of load. if anything may be connected, keep L&N shorted so no voltage can exist between them

 

[Andy™]

I only ever test N-E, as thats where most of the hidden faults lie.Its very unusual to have earth leakage L-E.

not as unusual as some may think. a fair amount of faults i find are L-E

 

[initforthemoney]

[quote name='Andy

 

[Andy™]

Indeed but not L-E.

sorry, the post should have read L-E.

i think its probably about 30-40% of callouts to RCD tripping are L-E

 

[batty]

[quote name='Andy