RCD holding but won't hold any load on any circuit

[Phil G]

Hi guys I've just rewires the power in a cottage due to the plasterer putting a few screws through cables. I have fitted a new wylex rcd 8 way board and I have got a shower,ring,ring,radial and lights on it. The rcd will hold but if you plug in more than a boiler or a radio it trips straight away. I've tested the circuits and there is no damage to any of them. The lights hold on now too. I've not caught a cable in a box or screwed through one. It's not a split load board so crossed neutrals isn't going to be an issue.

I'm really stumped. Any help would be great

 

[Clive P]

Hi,

Had a similar problem a long time ago, check the configuration of the internal link wires in the CU; you may find they are not corrected as they should be,

Regards.

 

[Phil G]

I have checked that and it all seems fine. Neutral out of the bottom of the rcd up to the neutral block.

The earth readings are good too 0.16 on a tn-s system

 

[bigbaddave]

Lighting on seperate RCD'S ?

 

[iamelectric]

have you tested the rcd , half current c if it trips might be faulty

 

[bigbaddave]

Lets start with the basics.. IR test results??

 

[Phil G]

I've only got one lighting circuit and its on the same rcd. I have tested the rcd and it came up ok. I've even swapped for a spare and that didn't help either

 

[DJ Ovengloves]

Have you tested for borrowed neutrals?

 

[bigbaddave]

I've only got one lighting circuit and its on the same rcd. I have tested the rcd and it came up ok. I've even swapped for a spare and that didn't help either

And you IR results are ?

 

[jay sean]

Have you reconnected any cables?, if you connect a neutral and earth the wrong way round with a RCD it will trip the RCD out when you have pluged in a load.

 

[chopper76]

IR results between e & n required as previously stated

 

[chopper76]

Probably a chaffed neutral in the back of a socket box

 

[Outspoken]

Jesus, why ask the question and then ignore the request for information.

• Have you completed IR Tests properly on all circuits and can you posts the results, as BigbadDave has asked a couple of times.
• Have you disconnected all the neutrals from the bar and then reconnected one by one (only one in at a time) until the RCD trips?
• Have you done the same with the earths?
• Was anything plugged into any of the sockets when you turned it on...if so, unplug it FFS.

Come on, you're a qualified spark and yet your struggling to test an RCD...if you tested it and it is not faulty as you have stated then the fault in in the installation and if you are properly qualified then you should know how to test the installation to find a fault...FFS, don't they teach them anything on these 5WWW courses??

 

[Octopus]

Why have you fitted a board with only one RCD?

 

[Badged01]

If its not a split board, theres only one RCD which is wired correctly and there isnt any visible problems at accessories then Id be thinking there is a neutral/earth fault somewhere in the wiring, thats the way your going to be tripping the RCD!

Logical fault finding as stated, IR test the indivdual circuits and if that doesnt show anything then start connecting/disconnecting the individual circuits until something gives. Then start investigating the circuit .....