Nuisance trippage of main incomer

[Psssst]

Hi all,

My situation is is this. I live in a house thats about 40 years old. The consumer unit is the original one . Its the grey metal wylex(?) which has a main switch over to the right and a yellow test button? I think its 100ma ?

The fuses have been replaced with mcbs at some stage. For many years, the main switch has suffered from nuisance trippage. It can happen as little as once or twice a year. Its been looked at a couple of times by electrician but the problem cannot be traced or replicated. Obviously this is very inconvenient because if it cuts whilst we are away then there are issues with security and the fridge/freezer etc.

Non of the MCBs have ever tripped. Its always the main switch.

Our incoming power cable enters the house and then loops out again to feed next door.

The elec meter, main inlet fuse and CU are all housed internally within a bog standard white meterbox. The sort of thing you;d seen outside, but this is inside. Obviously space for a CU swapout is a bit tight.

The general advice seems to be get the CU swapped and see what happens. Of course it could actually make it worse if there is a tiny fault somewhere,,,or ,,it could cure it if the main switch is a bit unreliable. All thoughts welcome.. Thanks (manchester)

 

[timhoward]

That would only be entirely true as long as D/P rcbos are being used of course.

A fair point, yes, I did make that assumption.

 

[Electro-tech]

Only a possibility, but I have experienced nuisance tripping several times & it has usually been a Fridge freezer plugged into the ring final Circuit. If you change the CU you may end up with a similar event, unless you put the F/F on a dedicated Rcbo circuit. If you go with all RCbo's & can separate each circuit will help to find future faults. It is probably earth leakage from the whole installation & the F/freezer then adds enough leakage to trip the RCD. Sorry Pc1966 , I have just noticed your post , just a senior moment & then I keep repeating things !

 

[pc1966]

Only a possibility, but I have experienced nuisance tripping several times & it has usually been a Fridge freezer plugged into the ring final Circuit. If you change the CU you may end up with a similar event, unless you put the F/F on a dedicated Rcbo circuit. If you go with all RCbo's & can separate each circuit will help to find future faults. It is probably earth leakage from the whole installation & the F/freezer then adds enough leakage to trip the RCD. Sorry Pc1966 , I have just noticed your post , just a senior moment & then I keep repeating things !

No worries!

Generally I would keep things like the fridge-freezer on the main RFC as if it trips you know pretty swiftly, where as if a dedicated one goes then it is only later when you find a defrosted fridge / rotting food that the situation mite be discovered. I guess some sort of alarm would be better, but simple option is simplest!

 

[mainline]

No worries!

Generally I would keep things like the fridge-freezer on the main RFC as if it trips you know pretty swiftly, where as if a dedicated one goes then it is only later when you find a defrosted fridge / rotting food that the situation mite be discovered. I guess some sort of alarm would be better, but simple option is simplest!

A basic socket power off alarm is quite cheap around £13 the more expensive ones send sms etc.
Personally, I have no need for one as the price of food is such that i can no longer afford to put anything in it