Entire board keeps tripping

[Deansplit]

Hi

There's probably not a single answer to this but in the hope for a bit of enlightenment, is there anything in particular which causes the entire board to trip rather than just the circuit breaker/fuse itself?

It's been happening for a 2-3 months now. The board is 1 of 3 we have, and they were all rewired 5 or 6 yrs ago after a bit of house restoration. Unfortunately, our garden lights don't have their own isolation box – I immediately thought it was these causing the problem (water getting into junction boxes/outdoor switches) as it appeared to be happening when someone went outside and the lights came on. So I looked at the boxes, and yes, there was damp inside one so I fixed that and wrapped in polythene. It seemed to be Ok for a while. However, the board also tripped when other lights in the house were switched so was this just a coincidence. Sometimes the main board switch won't reset immediately, it takes a few attempts.

There is a main junction box for our electric gate where the garden lights cable spurs off from to another box. I disconnected them at this 2nd box yesterday (1st one was hard to get to) just to try to eliminate that area. Low and behold, they tripped when the kitchen lights were switched on, so it can't be to do with the garden lights.

Could it be a faulty board, or even if the 1st garden box was damp, could this effect switches in say the kitchen when activated?

Any help gratefully appreciated.

 

[bernardgreen]

or even if the 1st garden box was damp, could this effect switches in say the kitchen when activated

Yes, an Neutral to Earth fault on a circuit can trip the RCD ( even if the MCB for that circuit is switched off ) when another circuit has a load on it.

Neutral_Earth_trip

• bernardgreen
• 16 Jan 2011
• 48

 

[Taylortwocities]

What exactly is "tripping"? I guess its an RCD, but please clarify.

It is very unlikely to be a "faulty board". It will be one of the devices or circuits connected to it.

Damp/moisture in electric circuits causes all sorts of problems. There are two ways to resolve this:

1. By isolating devices/circuits one at a time. Remember when isolating, you need to disconnect both the live and the neutral to the circuit. NOTE: Many switches (and the MCBs in your consumer unit) only turns off the live conductor. So you may need to take wires out.

2. By getting an experienced electrician with an Isolation Resistance tester to make a structured examination of your problem.

PS. If you have/had damp in an external circuit then it needs fixing properly. Water will get in anywhere if it can and wrapping in polythene will not mend it.
Properly installed external electrics do not suffer from ingress of water.

 

[Deansplit]

Ah, thanks, Bernard. Just to confirm we're understanding - the MCB's on the rest of the board aren't switched off, they're all on. What I meant was if the fault 'is' with the outside junction box/connection, but outside lights aren't on (but MCB for that circuit is), then when other lights are switched on, eg kitchen, this can still trip the board due to the fault with the outside box?

 

[bernardgreen]

this can still trip the board due to the fault with the outside box?

Yes it can, To check the circuit one has to disconnect both Live and Neutral of the suspect circuit to prevent the Neutral - Earth fault from tripping th RCD.

 

[Taylortwocities]

this can still trip the board due to the fault with the outside box?

Yes it can, To check the circuit one has to disconnect both Live and Neutral of the suspect circuit to prevent the Neutral - Earth fault from tripping th RCD.

Oh, how I wish I had remembered to mention that….

Remember when isolating, you need to disconnect both the live and the neutral to the circuit. NOTE: Many switches (and the MCBs in your consumer unit) only turns off the live conductor. So you may need to take wires out.

 

[bernardgreen]

Yes I missed that bit , sorry TTC

 

[crystal ball]

Properly installed external electrics do not suffer from ingress of water.

They may be properly installed at the time but future mistreatment may well allow ingress of water, as well as age deterioration