Testing problems (RCD) .........

[gazdkw82]

Sorry for the long post but i could do with ssome guodance here.

I had my practical initial verification assessment today. It was at 1pm so I decided to get up early and run some tests on my board at home as practice.

I did,

bonding
Cont cpc all circuits

However, upon continuity of the cpc I noticed that the cpc at light switch in the living room was open circuit.

Upon inspection I noticed one of the cpcs in the living light was not connected, it had been pushed up into the cieling void. I connected it up back and then I got a good reading at all points within the lighting.

I ran out of time at this point and decided to quickly do an RCD test on the RFC, Ze and PFC. All of which I'm pretty confident with.

However, upon checking the RCD I noticed the upstairs sockets we're not tripping the RCD. I had to really go at the point or else I would be late for my assessment. So I left the upstairs sockets turned off until I got back.

When I got back I decided to firstly make a cuppa. I turned the kettle on and I heard the RCD trip but the kettle was still on. I should point out here I have a split load board. The RCD that tripped when I turned the kettle on downstairs was the RCD protecting other circuits (upstairs sockets, upstairs lights etc) it wasn't part of the downstairs sockets. Only good thing was I had my cup of tea. Also i noticed that the downstairs hallway light tripped the RCD when I turned it on.

I just started to investigate and I got a call about my dad. He's had a TIA stroke so I'm currently in the hospital waiting to see him and thought I'd ask for some help here.

There isn't much I can do until probably tomorrow.

The only thing I've changed is connect the cpc's back up together in the living room.

Any ideas?

 

[Marvo]

Sorry to hear about your Dad, hope he recovers.

Start with dead tests.
Check IR of all final circuits. Test for borrowed or crossed neutrals between all final circuits.

 

[telectrix]

disconnect the cpc that you reconnected before. then if the tripping problem has ceased, that's the area to investigate. i'd suspect a N-E short or leakage on the cable that had the dissed cpc.

 

[Marvo]

The CPC was disconnected at the far end if I understand it correctly so I'm not sure why connecting it had such a profound effect on the RCD....

 

[gazdkw82]

Got back last night and had a quick look. Eventually found 2 other cables in the cieling void. So I had

Loop in
Loop out
Switch live (t+e sleeved)
Switch live for wall light (t+e sleeved)
T+e to the wall light

Took me around 40 mins belling out which was which with the switch and wall light.

I don't know what had actually happened but I've reterminated everything and it's all good. In going to check RCD times later today