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No. Get a new electrician to take a look.
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Could be an over-sensitive circuit breaker.
I've experience of one, but it took a knowledgeable sparky to diagnose it.
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i have the lowest sensetivity rcd as it is. i'll wait for a better sparky before i make any expensive purchases.
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We have an excellent circuit breaker, which trips even if a light bulb goes.
However, I have two surge protector extension leads and a surge protector mains outlet for my computer and these have never been tripped or caused the circuit breaker to operate to date; the mains outlet plug is around 12 years old.
Edited by Stuartli on 31/08/2009 at 23:29
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The tests usualy put a massive load on the circuit to check the quality of the insulation and the connections.
What have you got plugged into the surge protector? There could well be a faulty applience connected to that.
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i have the desktop pc, printer, scanner, screen, sound system and wireless router. they were all tested and are good.
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It might help you, if you know how RCD's work. They monitor the equality of the currents in the live and neutral leads -- the left hand and right hand socket pins when looking at a 13 amp socket. When this becomes unbalanced to the extent of about 30 milli-amps (0.03 amps) that trips the breaker.
Thus if you connect something between the live pin (left hand one) and the earth pin, on a 13 amp socket, and it takes more than about 30 milli-amps, it trips because the live wire is passing that 30 milliamps of current whilst the neutral wire (left hand pin) is taking nothing because you are using the earth pin as your other wire. (A circuit needs two wires)
You can do your own test to verify this. Connect a (two wire) lamp-holder between the live pin and earth pin, on a 13 amp plug, and have, say, a 15 watt lamp in it, and then plug it in. The RCD should operate (the one feeding that plug) as you will be taking about 60 milli-amps. Indeed, rather more before the lamp warms up.
From this you can see that your problem is usually caused by a wire having a leakage to earth -- inadequate insulation. That wire could be anywhere in your house that is fed through that the RCD that trips. The fault may be in your surge protector. Who knows. So why not take it out of circuit for a while and see if the problem goes away?
If the fault is elsewhere in your electrical system, you can narrow it down yourself by removing fuses (or opening the breaker) to turn off parts of the house and see if taking one particular fuse out, stop it. The electrician would do it by pulling all fuses and testing each wire using a megga -- a box of tricks that generates its own high voltage and shows if a wire has leakage. Before that he could test all wires together by using the main breaker to turn everything off. As that would leave all previously live wires still interconnected, and all neutral wires ditto.
Edited by buzbee on 02/09/2009 at 00:53
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Good detailed explanation - just to add one point. It is possible under certain circumstances (where the neutral has 'floated ' up by a few volts, for a short of neutral to earth in the consumer premises to cause a trip).
Can you however explain why a incandesent bulb will sometimes trip an rcd when it finally expires?
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pmh3
The short answer is ' no', not easily.
Was the bulb used in a metal lamp-holder, I wonder? Because that would usually be earthed as part of the larger lamp metal structure. Then, if the bulb failure some how managed to cause current to flow to the bulb metal cap, in that bulb socket, that would do it.
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Correction>
The right hand pin is the live, not the left one.
I wrote it and then changed them over when I posted it. Too much midnight oil.
Mods, can you alter please? The 2nd line should read "the right hand and left hand socket pins" .
The first line of 2nd paragraph should read "the live pin (right hand one)
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testing each wire using a megga -- a box of tricks >>
"Megger", at least that is what is used by the sparkies that I know.
And they would advise not to play with 240V mains electricity if you do not know what you are doing!
Edited by jbif on 02/09/2009 at 10:43
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thank's for all the advice. i have only energy saver light bulbs, no fillament type. i'm getting a new less sensative RCD fitted tomorrow, if the sparky turns up.
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Worth finding out what the problem is, IMO - if you've a 30mA RCD, and go to (say) an 80mA one, it could easily still trip. Favourite causes are things with heating elements in them. An incandescent light bulb blowing will not cause your RCD to trip.
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An incandescent light bulb blowing will not cause your RCD to trip.
When a bulb goes in our house, it often trips the corresponding circuit switch in the fuse box in the garage. Is that anything to do with RCD?
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From - www.diydoctor.org.uk/projects/bulbs.htm
When a bulb blows, 99% of the time the fuse for the lighting circuit will blow or trip also. This makes the problem seem rather bigger than it actually is. The reason for a blowing lamp tripping an MCB is that the lamp element gets thinner during its life to the point where it breaks at the thinnest point, this point will melt just before failure. The resistance of the overheating element will momentarily be very low and a current surge is caused, this is picked up by MCB's but generally not fuses.
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>>An incandescent light bulb blowing will not cause your RCD to trip. <<
It can and it does sometimes. Been the subject of much discussion as to why it can happen.
(And I do mean RCD not MCB)!
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An incandescent light bulb blowing will not cause your RCD to trip.
In my house it trips the lighting circuit MCB 75% of the time. Depends on how the bulb fails.
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>> An incandescent light bulb blowing will not cause your RCD >> to trip. In my house it trips the lighting circuit MCB 75% of the time. Depends on how the bulb fails.
Yes, normally due to excessive current tripping the (6A?) MCB, I get this too, but have mainly "energy saving" lamps now, & haven't had a problem with those.
I should be interested in an explanation od (PMH's?) assertation that RCDs can and are tripped by incandescent bulb failure - a very rare event, surely?
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Close to 100% in mine, though not the 12v halogens obviously.
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Failure of an incandescent bulb will trip a trip and will also often blow a conventional capsule fuse or fuse wire. Not always perhaps, but often.
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>>>>I should be interested in an explanation od (PMH's?) assertation that RCDs can and are tripped by incandescent bulb failure - a very rare event, surely? <<<<
FT
Not that rare event - several of us had seen it happen and pondered as to the reason why.
After much discussion, a group of us (who were largely CEng MIET, but not in the 'power environment') came to the conclusion that the tripping was due to the effect of the very high surge current (very short term), and small differences in the 'windings' on the 'Live' and 'Neutral' coils causing the trip to operate. The RCD operates on the differential 'Amp -Turns', and at normal operating currents the difference in windings is of no consequence until there is a current differential.
If you have a different viewpoint would be interested to hear it.
PS be warned - if the thread is made Read Only while you are posting a reply you stand a chance of losing your reply. Only saved because I now always 'copy' before hitting Post
I was editing as you posted - I've moved it into 308 so it makes easier reading
Edited by Pugugly on 03/09/2009 at 15:34
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> Not that rare event - several of us had seen it happen and pondered as to the
> reason why.
>
> After much discussion, a group of us (who were largely CEng MIET, but not in the
> 'power environment') came to the conclusion that the tripping was due to the effect
> of the very high surge current (very short term), and small differences in the
> 'windings' on the 'Live' and 'Neutral' coils causing the trip to operate.
That sounds like a possible mechanism - however, I still think it must be a rare event. Most people of course refer to the "RCD" tripping when they don't *mean* "RCD".
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Took me ages to work out why the RCD to my garage kept tripping - Sorry if that is not the right expression, FT - It was my approach light wot did it. Replaced with a dusk-to-dawn low-energy sensor bulb. No more problems and a big cost saver over the years...........
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Most people of course refer to the "RCD" tripping when they don't *mean* "RCD".<<
The credibility of the group who were discussing it was not in question, several of us had seen it happen and were surprised. However the average man in the street does not understand the issue, (or various 'qualified' electricians!).
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