Trip switch on consumer unit

[Deleted User]

Hi, I have an electric problem which I hope someone can please give me some advise. Whenever I switch an on an appliance (by that I mean switch on the socket at the wall with the appliance already plugged in), the trip switch on the consumer unit switches off. It only happens on 3 wall sockets and it doesn't happen on every occasion. The wiring has all been done by a fully qualified electrician, so I don't think there is problem with the wiring itself. I know I may end up getting an electrician in, but does anyone have any idea what may be causing this.

fwor

Not quite enough info to be certain, but if it's the same appliance every time, it implies a fault in the appliance's cabling or internal to the appliance.

If it happens with ~any~ appliance it implies that the socket wiring is faulty, though from an initial think of the possibilities, it's not easy to imagine specifically what that fault could be.

[Deleted User]

fwor wrote: »

Not quite enough info to be certain, but if it's the same appliance every time, it implies a fault in the appliance's cabling or internal to the appliance.

If it happens with ~any~ appliance it implies that the socket wiring is faulty, though from an initial think of the possibilities, it's not easy to imagine specifically what that fault could be.

Thanks fwor for your reply. Yes it's the same appliances, although I doubt if there is anything wrong with the appliances themselves - it's my laptop on 1 socket and a TV on the other socket. I don't know if the fact that I have adaptors and socket extension cable plugged into these sockets may be causing the problem - I thought it could be an overloading issue but I don't know enough to be able to say for certain. The funny thing about it is that if I leave the socket itself switched on and simply push in the appliance plug into the socket, the trip switch doesn't cut out. Again, I can't be absolutely sure about this, as the problem is not consistent. Would it take an electrician a long time to resolve the problem?

Rabbir1

When you say "trip switch" do you mean a MCB or a RCD? A RCD will have a test button on it. If its a MCB tripping, what is the rating writen on it? It will be something like 32A or 20A etc. .

fwor

Rabbir1 wrote: »

When you say "trip switch" do you mean a MCB or a RCD? A RCD will have a test button on it. If its a MCB tripping, what is the rating writen on it? It will be something like 32A or 20A etc. .

That's a very good point - I was assuming that it was the RCD (the main cutout) which will normally cut all power to the house.

If it's just one circuit breaker, leaving the rest of the circuits working, then it implies that too much current is being taken for the rating of that circuit breaker.

There are several possible causes that might not need an electrician - for example if it's a large old CRT TV, these can take very large surge currents if turned on after being off for a while, and this can trip an MCB. It should not trip the main house breaker though.

[Note that the above can be more complex if your consumer unit is fairly recent, as it may be what is termed "split load"]

[Deleted User]

fwor wrote: »

That's a very good point - I was assuming that it was the RCD (the main cutout) which will normally cut all power to the house.

If it's just one circuit breaker, leaving the rest of the circuits working, then it implies that too much current is being taken for the rating of that circuit breaker.

There are several possible causes that might not need an electrician - for example if it's a large old CRT TV, these can take very large surge currents if turned on after being off for a while, and this can trip an MCB. It should not trip the main house breaker though.

[Note that the above can be more complex if your consumer unit is fairly recent, as it may be what is termed "split load"]

I just checked the consumer unit and next to the switch that turns off it says RCD 63 2 30T. Not sure if this means anything. You're right about the house breaker - that stays on, it's only the ring main that turns off, and all I have to do is switch the circuit breaker back on. You could be right about drawing too much current - if this is the case, what can I do about it.

[Deleted User]

You guys are so clever - I just checked my TV ( Phillips LCD), attached to it's plug, there is what I think is some sort of transformer. It seems to take in 240V and output 12V - could this be the cause of the RCD tripping. I also have a similar adaptor (65W ac adaptor) on my dell laptop. If it's these, what can I do about it to stop the RCD from tripping.

Rabbir1

Not clear from your reply if its a RCD or MCB tripping. If it is the one that says "RCD 63 2 30T" then its the main RCD and that would take out all the circuits after it and not just the 1 ring circuit (unless that is the only circuit).

If it is that though, then you have a fault on any one of the items plugged into the circuits that are being controlled by the RCD.
The best way to find the fault is to unplug everything and then plug back in one at a time. However, if it is a intermittent fault, this could take a while. You need to unplug everything including adapters and leads. Also dont just switch the sockets off as they may not have double pole switches.

fwor

[quote=[Deleted User];49762017]I just checked the consumer unit and next to the switch that turns off it says RCD 63 2 30T. Not sure if this means anything.[/QUOTE]

Markings suggest that it's a 30mA RCD, fitted (for some unknown reason - maybe an electric shower elsewhere on it?) just on that spur. 30mA is quite sensitive - IIRC, whole-house RCDs are rated at 100mA, so much less likely to trip.

As you say it's the RCD tripping, there seems no doubt that one or other of the appliances is not as it should be.

One specific question: Does the room where this happen get damp (as in condensation-causing damp)? I've seen a situation - in a garage/workshop - where levels of condensation were so high that the RCD would trip occasionally.

[Deleted User]

Rabbir1 wrote: »

Not clear from your reply if its a RCD or MCB tripping. If it is the one that says "RCD 63 2 30T" then its the main RCD and that would take out all the circuits after it and not just the 1 ring circuit (unless that is the only circuit).

If it is that though, then you have a fault on any one of the items plugged into the circuits that are being controlled by the RCD.
The best way to find the fault is to unplug everything and then plug back in one at a time. However, if it is a intermittent fault, this could take a while. You need to unplug everything including adapters and leads. Also dont just switch the sockets off as they may not have double pole switches.

The trip switching off is the one labelled RCD 63 2 30T. There is also a test switch just above it, but don't know what this does. From what you're saying, if it's the main RCD, I think I may have a serious problem as only the ring main goes off ( there is only 1 ring main as it's a bungalow), but also the oven goes off - I thought this would be on a separate circuit. However, the lighting is not affected - all lights stay on. Should the lights also go off when the main RCD trips?

fwor

[quote=[Deleted User];49763723]The trip switching off is the one labelled RCD 63 2 30T. There is also a test switch just above it, but don't know what this does.
[/QUOTE]

The Test button simply simulates a fault on that circuit, and should cause it to trip. But you know it's working anyway.

[quote=[Deleted User];49763723]From what you're saying, if it's the main RCD, I think I may have a serious problem as only the ring main goes off ( there is only 1 ring main as it's a bungalow), but also the oven goes off - I thought this would be on a separate circuit. However, the lighting is not affected - all lights stay on. Should the lights also go off when the main RCD trips?[/QUOTE]

The one that's tripping out should not be the main house one. That should be marked something like RCD 80 2 100T.

Otherwise it would appear to be a very non-standard installation which would not meet current regulations, and should be examined by a qualified electrician.