R.C.D. trip on array

[KEVINDOE]

Greetings all,

I was called to a farm house today just to replace a stand alone P.I.R. detector, i had not been there before, whilst chatting over some awfull coffee,
The guy was saying that he had a P.V. instalation fitted two weeks ago , the instalation firm however have to come back as between 5pm and 7pm the main 100ma R.C.D trips...every day..without fail ..rain or shine..its TT ..and has the old type D.N.O fitted unit..i know these can be sensitive,
but why at that time of day ??

Jemma:75:

 

[seprim]

If it is at exactly the same time of day, this may help. Are there any timers on the circuits on the distribution/main board ? There may be a fault on one of these circuits. It is unlikely to be the PV installation, however one must never assume, and also from my experience it probably wont be a PIR, as they usually switch dawn and dusk, and 5pm to 7pm at this time of year isn't near that.
do a couple of things:
1. Ask customer if they have put any nails, picture hooks or fixings into the walls recently. If they have - check it out.
2. look at the fixings for the pv run - do they run any cables (new) where old cables may be ? Did the pv company do any other works at the same time as the pv install ? check it out.
3. check the lighting circuits to see if they have timers on any of them (in fact check all circuits for timers for that matter). If you find one, operate it manually to see if it takes the RCD out.
4. check the immersion heater/central heating to find what time it switches, operate it manually to see if it takes the RCD out.
Ensure you advise the customer that the power may be going off so vulnerable people, animals and computers or other equipment may be affected - your routine checks should cover these.
Remember neutral - earth faults takeout RCD's and are tricky to find sometimes.
Good luck - come back if you have any more data and the cause of the tripping still has you stumped

Andrew

 

[KEVINDOE]

Thanks Andrew,

Thats a helpfull post..the customer is keen to let the installation firm sort it out, i dont think ther local so it might be the case that they get us to have a look around,
im back ther next week so i will post any info , or if its sorted, what the problem was..thanks again for your reply.

Jemma