RCD Trips when we get heavy rain?

[AshFR]

Hi all. Got a bit of a problem. When we get heavy rain like we did today, the RCD trips. So i push it back on and sometimes it will stay there for months or it sometimes again instantly. Any idea what the problem is? I do have 2 outside lights and a PIR sensor on them. Im thinking the problem lyes there but could do with a bit of advice to testing it. It will come in handy aswell as i need a fault finding job for my college work Thanks all.

 

[i=p/u]

IR test your suspect cable soon as trips

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check for moisture around cables, dont look at it , just do it.

 

[Marvo]

Have you got a mega tester?

 

[AshFR]

IR test your suspect cable soon as trips

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check for moisture around cables, dont look at it , just do it.

Ok cheers.

Have you got a mega tester?

I have indeed

 

[Marvo]

I would isolate the suspect fitting at the point of supply and test the circuit and fitting together. Might be worth just running a 250v test, the passive might not enjoy the higher voltage tests.

 

[Jimmy Boy]

Hi all. Got a bit of a problem. When we get heavy rain like we did today, the RCD trips. So i push it back on and sometimes it will stay there for months or it sometimes again instantly. Any idea what the problem is? I do have 2 outside lights and a PIR sensor on them. Im thinking the problem lyes there but could do with a bit of advice to testing it. It will come in handy aswell as i need a fault finding job for my college work Thanks all.

The devil is in the detail, if your going to fault find start with the bottom and work up.
What are the supply arrangements ? TT TNS or TNCS ? this may then lead us on to where the RCD (s) may be in the installation, is it an up front RCD as a main switch or a split load board ? sounds like you have a spur off a RCD protected radial/ring ?..Not good,get back to us but I suspect if it is fed from another circuit, pulling the L/N out will cure it
J

 

[AshFR]

I would isolate the suspect fitting at the point of supply and test the circuit and fitting together. Might be worth just running a 250v test, the passive might not enjoy the higher voltage tests.

Ok buddy will do that. Thanks very much

 

[Strima]

I'd be tempted to isolate and have a quick look at the outside lights, their drains probably can't keep up with heavy rain.

 

[AshFR]

The devil is in the detail, if your going to fault find start with the bottom and work up.
What are the supply arrangements ? TT TNS or TNCS ? this may then lead us on to where the RCD (s) may be in the installation, is it an up front RCD as a main switch or a split load board ? sounds like you have a spur off a RCD protected radial/ring ?..Not good,get back to us but I suspect if it is fed from another circuit, pulling the L/N out will cure it
J

It is a TNCS system The RCD is a main switch in the C/U.

 

[Jimmy Boy]

It is a TNCS system The RCD is a main switch in the C/U.

Thats a barsteward lol

What circuit is the outside lights dipped in to ? Power ?
J

 

[AshFR]

Thats a barsteward lol

What circuit is the outside lights dipped in to ? Power ?
J

It is lol. They are spur from a downstairs light.

 

[Jimmy Boy]

Can I also remind you to carry out a full isolation procedure with lock off fella, PIR's and Photocells are especially risky, I hope you have your testers, if you have a RCD as a MS it will be DP so your good to go,but breakers are SP so beware of N faults, test test test !
J

 

[Jimmy Boy]

It is lol. They are spur from a downstairs light.

IF the spur is a DP isolator as opposed to a FCU it will clear the fault, if not you will need to whip the N out after the safe isolation is carried out
J

 

[AshFR]

Can I also remind you to carry out a full isolation procedure with lock off fella, PIR's and Photocells are especially risky, I hope you have your testers, if you have a RCD as a MS it will be DP so your good to go,but breakers are SP so beware of N faults, test test test !
J

Yes buddy. Always do :d Why are PIRs risky then? Yeah its definatly as a MS.

IF the spur is a DP isolator as opposed to a FCU it will clear the fault, if not you will need to whip the N out after the safe isolation is carried out
J

Well theres just a cable coming from a perm live to a normal switch then out to the lights/PIR.

 

[Jimmy Boy]

Well some naughty boys..Use a 3 core as a L/N/ E as sw L this is common, especially on PCells,I had it this week on some pyro,naughty very naughty boys, assume nothing you will live longer lol, get a GS 38 tester and use it mate ALWAYS