I'm a self empoyed electrician, have been for many years, but have come across a problem that's got me stumped. I've fitted a new split load board into a bar and restaurant. Most of the installation is original, a couple of new rings is all I've put in. Trouble is, whenever something with an inductive load is turned on, like a drill, or a flourescent light fitting, it trips the RCD, even if the fitting is on the non RCD side. The insulation test is reasonable, the worst being around 8 ohms. The RCD tests ok, no trip at half fault. I did think about putting a time delayed RCD on the circuit, but that would take the trip time to around 400 ms, too slow for the regs! Any ideas, anyone..............
2006-11-21 08:16:11 · 11 answers · asked by andygos 3 in Home & Garden ➔ Maintenance & Repairs
Ok, I didn't solve the actual problem. It Wasnt a neutral fault, as it didn't trip every time something was plugged in or turned on, just if you turned on a big inductive load, like 4 or 5 flourescents at once, or a powerful motor. I got over it by changing the RCD for a regular incomer, and putting RCBOs (individual earth leakage trips) on each of the circuits that required RCD protection.
2006-11-23 08:28:58 · update #1
I dont believe upgrading the mcb will cure the problem as it is tripping the rcd not the mcb (An rcd senses any "Imbalance " in current between live and neutral (Not overcurrent).I would agree with robert and check neutrals (and lives just incase) are not cross wired somehow to the non rcd side,easy mistake to make but can have you baffled for ages!
Max
Qualified spark
2006-11-21 09:51:09 · answer #1 · answered by maxkd2000 1 · 0⤊ 0⤋
OK
I have had this problem before.
Nothing trips until you plug it in and turn it on ?
You have one or more neutral cables on the wrong Neutral Busbar.
The circuit is fed from a Breaker that is protected by the RCD, but the neutral(s) are on the wrong terminals.
I think this is what you have done.
There are two Neutral bars on a split load board and the second one is served by the RCD.
You have put the Neutrals in the first one.
Had this happen many times with other electricians.
2006-11-21 09:20:25 · answer #2 · answered by robert22061954 3 · 1⤊ 0⤋
Definitely has to be the neutrals mixed. If its not at the DB then have a look at 2 way lights might have picked a neutral up from some other circuit especially on a stairway light.
Might have been a heating engineer for 40 yrs+ but I did serve my time as an electrical fitter
2006-11-21 11:55:38 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Hiya.
Have about using a different breaker? I don't mean a higher rating I mean one which is more tolerant to inductive loads (eg: motor start)
I think the breaker types are B-type (normal domestic) and "C" type - suitable for indcutive loads
If a fluro is tripping though this seems dodgy - unless you mean a whole load of them and they are LPF instead of HPF.
Hope that helps.
**update ** rhschap, RCD = residual current device - "Earth leakage breaker" I think for you guys over the pond
2006-11-21 08:30:15 · answer #4 · answered by Mark T 6 · 0⤊ 0⤋
hi there, i have had this happen to me before.
The problem then was the neutrals, check and make sure that all the neutrals are on the correct side of the RCD. Normally the ring mains can cause this problem if one leg is on either side.
Just a thought, would love to know what you find out
2006-11-21 08:35:44 · answer #5 · answered by hartmarina 2 · 2⤊ 0⤋
It is probably because of the inductive loads which cause spikes or momentary surges on start up. I would uprate the CB by the next available rating and put a slow blow fuse at the original value somewhere else in the same circuit.
2006-11-21 08:52:31 · answer #6 · answered by ask this dummy 4 · 0⤊ 0⤋
Use a breaker that trips on the actual load in current and not on the heat produced from the current. Initial load of motors is also a consern.
2006-11-21 13:06:06 · answer #7 · answered by blue_eagle74 4 · 0⤊ 0⤋
I haven't either, and I've been doing electrical for 60 years. What the devil is an RCD? Also, in what country are you working? (For me, USA.)
2006-11-21 08:27:58 · answer #8 · answered by Anonymous · 0⤊ 0⤋
DAGGUM!
Sounds like one for the books.
Was the building having trouble before the new installation?
An old timer that guided me putting all new electric in my house told me, "90% of electrical problems come from a bad ground."
Bet you'll have to disconnect all the circuits and check them one at a time.
Good luck....
2006-11-21 08:31:41 · answer #9 · answered by FAT CAT 4 · 0⤊ 0⤋
I've been doing this a long time.....and I'm sittin' here scratchin' my head
2006-11-21 08:32:33 · answer #10 · answered by johnnydean86 4 · 0⤊ 0⤋