Electric tripping
- Thread starter Pnd123
- Start date
Looks like an Active RCD
Extra safety - When the power is lost due to an earth fault or power cut, the active or non-latching RCD isolates the circuit that it is protecting and remains off until it is manually reset. A must for protecting circuits supplying rotating machinery or some heating apparatus for example.
Extra safety - When the power is lost due to an earth fault or power cut, the active or non-latching RCD isolates the circuit that it is protecting and remains off until it is manually reset. A must for protecting circuits supplying rotating machinery or some heating apparatus for example.
Yes.
I will guess that you have a single 30mA RCD protecting your whole house.
It is strange that yours appears to be lying on the kitchen worktop rather than installed in the consumer unit or a separate enclosure
Photos of your consumer unit will reveal if it can be updated or if it needs to be replaced.
Not as old as I was expecting, but I agree it would be preferable to replace it with a modern one. You will need a qualified electrician who is a member of a self-certification scheme such as NICEIC. This is also a good time for any improvements such as cooker or shower circuits, garage or loft sockets, or additional points. I expect your cabling will be in PVC and most likely still in good condition.
Instead of the MCB breakers, I recommend an RCBO for each circuit. This costs more, but has the advantage that a fault on one circuit does not cause the entire installation to go off.
I think your main problem is that the total load of the whole house goes through one RCD, so that small leakages on multiple circuits add together. I have used the Wylex breaker you show, it might be 30 or 40 years old, and they were latching, so I don't think that's the trouble, although it might possibly be a special version I did not come across.
Instead of the MCB breakers, I recommend an RCBO for each circuit. This costs more, but has the advantage that a fault on one circuit does not cause the entire installation to go off.
I think your main problem is that the total load of the whole house goes through one RCD, so that small leakages on multiple circuits add together. I have used the Wylex breaker you show, it might be 30 or 40 years old, and they were latching, so I don't think that's the trouble, although it might possibly be a special version I did not come across.
In the meantime, reinstall it in the CU.
Turn off ALL the MCB's, reset RCD
Then turn on the MCB's about a minute apart and you might find 1 circuit that causes the trip
Turn off ALL the MCB's, reset RCD
Then turn on the MCB's about a minute apart and you might find 1 circuit that causes the trip
He said it was a pic (of a similar RCD unit) on Ebay, therefore not his own he had removed
I have done that on a few occasions but the problem seems to be when they are working in the substation and/or whenever the electricity goes off in the whole street.
It's a pain to have to switch it back on.
I came home from work today and it was off, apparently most of the village had gone off for a few minutes.
Both neighbours never had to reset their consumer unit
Thanks
Last edited:
- Joined
- 11 Jan 2004
- Messages
- 43,322
- Reaction score
- 2,758
- Country
It is a latching 80A 2 pole RCD to BS4293.
From memory, that generation of consumer unit clad in plastic were around in the early 1980s, but I have worked on installations with metalclad versions that were installed in the 70s. Either way, it's earned its keep.
As previously mentioned, you would be much better off with a new consumer unit housing a bunch of RCBOs.
From memory, that generation of consumer unit clad in plastic were around in the early 1980s, but I have worked on installations with metalclad versions that were installed in the 70s. Either way, it's earned its keep.
As previously mentioned, you would be much better off with a new consumer unit housing a bunch of RCBOs.
I got two in everyday use still tests OK and have worked on the odd occasion of a fault.
One important thing to do in my humble opinion (with any RCD) is to press the button at no more than three month intervals - for the ordinary person it gives a quick guide as to if it might work or not when needed and more importantly doing that, or indeed tripping it manually, gives it a quick wipe and reduces the chance of "Stiction" , you do not want a sticky switch RCD slowing down an operating RCD in those vital milliseconds of trip.
One important thing to do in my humble opinion (with any RCD) is to press the button at no more than three month intervals - for the ordinary person it gives a quick guide as to if it might work or not when needed and more importantly doing that, or indeed tripping it manually, gives it a quick wipe and reduces the chance of "Stiction" , you do not want a sticky switch RCD slowing down an operating RCD in those vital milliseconds of trip.
- Joined
- 27 Jan 2008
- Messages
- 24,313
- Reaction score
- 2,777
- Location
- Llanfair Caereinion, Nr Welshpool
- Country
It seems circa 1983 for these old units, looking at flameports website. In the main at the consumer unit they were passive units, at the end of a circuit we used active away from the consumer unit, as with a volt drop so of the old units would fail well before hitting 50 volts, But theses old units do not like spikes, and with my old house, if one tripped, on resetting it was common to find it would trip the other in the pair, and would need to turn off all MCB's to be able to reset.
Also, for no found reason, I would get bouts of tripping, maybe 5 times in 2 weeks, then would do 2 years or more before tripping again. Just before moving I lost the contents of the freezers, due to tripping while not home, so in this house we had all RCBO's which have only tripped with good cause.
We should when fitting RCD's ensure the background leakage does not exceed 30% of the rating, however my old meter left
would not measure 9 mA, and it was not until a couple of years ago I upgraded to one on the right, which will measure 9 mA, so often the background leakage (AC will always have some leakage) resulted in the unit tripping well before a 30 mA fault.
Also, for no found reason, I would get bouts of tripping, maybe 5 times in 2 weeks, then would do 2 years or more before tripping again. Just before moving I lost the contents of the freezers, due to tripping while not home, so in this house we had all RCBO's which have only tripped with good cause.
We should when fitting RCD's ensure the background leakage does not exceed 30% of the rating, however my old meter left
would not measure 9 mA, and it was not until a couple of years ago I upgraded to one on the right, which will measure 9 mA, so often the background leakage (AC will always have some leakage) resulted in the unit tripping well before a 30 mA fault.
- Joined
- 11 Jan 2004
- Messages
- 43,322
- Reaction score
- 2,758
- Country
I have a similar setup that we inherited when we bought the house, albeit our board is 10 years younger. But it is a plastic consumer unit with one RCD protecting all the circuits. I have had a few trips over the 25 years we have owned the gaff, but I have been lucky and all have had a known cause that I was able to trace. I use the test button a few times every year and once in a while will test the RCD and do a ramp test.
It will get pensioned off and I will get someone in to swap it out in the next few years.
It will get pensioned off and I will get someone in to swap it out in the next few years.