RCB keeps tripping

[spike47]

Hi

I seem to be having a strange problem with my 9kw shower , the RCB keeps tripping every time I switch the main ceiling double pole switch off , it is fine when using the shower but we have to reset the RCB every time someone finish's using the shower . I could understand if the problem was when we switched the shower on , but I can't understand how it happens when it is switched off .

ps: this seems to have started to do this about 2 months ago , nothing new fitted .

cheers

spike

 

[Pete999]

Water leak within the shower

 

[Octopus]

Is it a MCB or a RCD?

 

[Pete999]

Good point Murdoch, although the OP does say RCD, could be he 's not sure if it's an RCD.

 

[GLENNSPARK]

when the shower is turned off...the water from the head is dribbling onto the case.....getting in and causing the RCD to trip?

there is a leak on the shower tray...this finds its way to a joint box/damaged cable under the floor...the water from the leak takes a little while to find its way....?

 

[spike47]

when the shower is turned off...the water from the head is dribbling onto the case.....getting in and causing the RCD to trip?

there is a leak on the shower tray...this finds its way to a joint box/damaged cable under the floor...the water from the leak takes a little while to find its way....?

Hi

Sorry Guy's I should of stated the RCB trips when I switch the main Double pole ceiling switch off .

 

[Richard Burns]

I would expect that the switch is causing a transient current spike as the contacts arc on denergisation that is enough to cause the RCD to trip.
This may be due to an old RCD or one that is very close to tripping if it is a shared RCD, or that the switch contact has become damaged by the current flow and needs replacing.

 

[Rockingit]

My guess would be that if you've been (incorrectly) using the pull cord ISOLATOR as an everyday switch then the contacts might have started to wear down and there is some arcing under disconnection. My advice would be to leave the isolator ON and just use the functional switch on the shower as designed - if the problem goes away then there's your culprit.

 

[spike47]

I would expect that the switch is causing a transient current spike as the contacts arc on denergisation that is enough to cause the RCD to trip.
This may be due to an old RCD or one that is very close to tripping if it is a shared RCD, or that the switch contact has become damaged by the current flow and needs replacing.

Hi

Thanks for your replies , the RCB is only 2 years old , and I have checked the contacts on the pull switch they look like new , that is because the pull switch contacts are never used as a live switched load , the load comes on with the shower unit switch after the pull switch is activated .

spike

 

[Deservices]

Even thou it's not being used on load, it's still a isolator, it's not designed to be used every time you use a shower. Could be the springs in the switch, so it switches live neutral at different times. Combined with possible other loads on the RCD. Is it a rcbo or a MCB and a main RCD?

 

[Plonker 3]

What tests have you carried out?
what were the test results?
what is the earthing arrangement?

 

[tony mc]

Have you checked the connections at the CU and made sure that they are all good and tight ?

 

[Octopus]

Good point Murdoch, although the OP does say RCD, could be he 's not sure if it's an RCD.

the OP says RCB!

 

[tony mc]

Looking at your CU it looks like the shower is not RCD protected that is if this is the CU still in your house ?

To Build a Double RCB Consumer unit

It looks like cct 5 or 6 is the shower !

I have put my glasses on and have seen the stand alone CU for the shower !!