Fuse box tripping

[SPF]

I wonder if anyone can help me please?

One circuit on our fuse box keeps tripping. Its the one with central heating pump, fridge and a few other downstairs power points etc on, nothing too heavy. The odd thing is that it did this once before and then resolved. When I go to reset the tripswitch, it immediately trips again. But the longer I leave it between attempts the longer it will last before tripping. Its only a matter of seconds but it seems rather strange.

Last time, we left it three days, and when we reset it, it was fine.... This time though no joy and no hot water!

Any thoughts? Or is it straight to the electrician?

 

[andy]

try and narrow the fault down. does it still trip with everytihg unplugged? yes - faulty circuit. no - faulty appliance

 

[SPF]

It does trip with everything unplugged. I was thinking it might be the fusebox itself- but the circuit is more likely?

Thanks for responding so fast by the way!

 

[Hacman]

Is it the RCD thats tripping or the MCB

If the MCB stays up and the RCD trips then,

1. You have excessive earth leakage, caused by either a faulty appliance
or cumalative appliances leakage totalling +30mA

2. You have a neutral/earth fault on your circuit.

If the MCB is tripping then you have a short circuit L/N or an overloading problem.

 

[Hacman]

Have you put any pictures up etc, done any diy recently?

As 99 percent of all this kind of fault in council houses are caused by people putting up pictures etc and nailing straight into the cable run.

 

[plugwash]

what rating is the breaker what is the cable size and is it a ring or a radial.

as i see it there are 3 possibilities

1: a fault with one of the fixed appliances you can't unplug
2: a cable fault (possiblly caused by past overloading of the cable)
3: a dodgy breaker (they don't last forever).

 

[SPF]

No nothing changed recently- that I can think of anyway.

We have a box with two rccb switches- each having three c60HB switches next to them. It is the c60hb that is tripping and taking one of the rccbs with it. The rccb is fine if you switch it back so long as you dont reset the C60 as well...
The label under the c60 states "FIrst floor ring circuit" though it seems to cover the kitchen and then half of upstairs...

 

[baldelectrician]

have you any outside lights wired to that circuit?

sounds as if it may be water

 

[SPF]

I don't think so. Certainly nothing we've used of late. I wonder, however, whether the septic tank pump is on that circuit (potentially unpleasant if it is!!!)

This morning, I went to see if I could remove the breaker with a view to getting a replacement just in case thats the problem. On the off chance, I flicked the switch first, and it turned on without tripping... Very odd.

 

[mapj1]

if you have identical breakers in the box you could swap the circuits or the breakers over and see if the fault transfers or stays. However, I'd suggest confirming the spetic tank theory, and making sure you know exactly what goes off with that switch (and label it for next time). You mention no hot water - is there an immersion heater on that loop ?- a classic fault when they start to rot off is water in the element causeing problems that are dependant on the water temperature or thermostat setting until it finally goes pop- and as others have mentioned, just switching off single pole is not enough, as a neutral to earth fault can cause tripping of an RCD.
If in doubt isolate L and N of any suspect loads for any 'does it trip now' test.

 

[securespark]

I get this kind of call very often, and 99/100 it's a faulty appliance that is forgotten. Maybe it is connected by a FCU or it is out of sight, but when it is disconn'd, the fault disappears. All portable or fixed equipment must either be on a plug/socket arrangement, or connected via a DP switch.

Make sure the plug is out, or the switch off.

This list is neither exhaustive nor may all of it apply to your case, but don't forget boilers, showers, pond or other pumps, outside supplies, security lighting, portable appliances (inc kettles, irons and toasters, washers, dryers, dishwashers). Basically any circuit that has equipment attached to it that uses water can be a culprit. Think hard!

 

[plugwash]

Make sure the plug is out, or the switch off.

and if its a switch make sure it really is double pole