Consumer units tripping out

[DerekBlakey]

Hi Everyone

I have just joined this forum as I am having problems with my consumer unit tripping out. I dont have any formal electrical qualifications so please excuse my ignorance.

It is a modern 8 fuse consumer unit where the circuit can be reset.

Occasionally the whole consumer unit will trip out with the mail switch being in the off position.


Switching this back on trips out circuit 3.


Circuit 3 has a 16 amp fuse.


Circuit 2 and 1 have 32 amp fuses, the reason for telling you this will become apparent shortly.


Circuit 3 has the largest number of rooms/equipment on it out of all of the circuits. Currently there is

• outside security light
  
• a light in the loft
  
• power sockets in the loft
  
• my sons bedroom with 2 PCs, TFT TV, computer screen, sound mixer and 100watt guitar amp. There are also, I guess and assortment of smaller phone chargers etc
  
• My Wifes office with 1 PC and 2 TFT screens, inkjet printer and numerous phone chargers
  
• My office with 5 PCs ( which run 24/7) , 3 TFT PC screens, HP laserjet printer, 24 port network switch, broadband router and a 6 port gigabit switch.
  
• Whirlpool bath ( although currently the fuse has been removed to assit in finding fault)

Circuit 2 simply has a two oven cooker attached.


Circuit 1 has the kitchen, TFT TV and assortment of small kitchen type gadgets.


I have tried to isolate the issue with circuit 3 by removing equipment on at a time, but because for most of the time the fault is intermittent this has not really sorted the problem.


My feeling as a none electrician is that the circuit simply does not have a big enough fuse in it. I realise without being here it may be difficult to say but what would the consensus be on my theory.


If that is the case is it possible to swap around the fuses from circuits 2 and 3.


Is it even possible to change these fuses now or am I stuck with a 16 amp fuse on circuit 3.


Any assistance on this would be appreciated.


Many thanks


Derek

 

[Darkwood]

Welcome to the forum Derek

I have approved your post for the general forum although when admin is next online you may be given DIY status and the thread relocated, this won't effect any postings already made.

In answer to your query it sounds like you RCD is tripping and this is probably due to the high number of device that have natural earth leakage, usually electronic devices, computers etc... when you reset the rcd the combined inrush of all these devices trying to start up is probably why you see the circuit breaker trip, if you switch off the loads first before resetting then turn them on one at a time this should resolve that part of the issue. As for the leakage (if this is what is causing the issue) you may need to have your circuit layout looked at and possible alterations so not to have 1 rcd looking at several circuits if there is a large number of devices with designed leakage on them.

 

[telectrix]

beaten by the darkhorse. almost certainly leakage from all the IT and electronic gizmos.

 

[DerekBlakey]

Hi

Thanks for accepting me into the forum and for the information.

I agree that the circuit layout is not the best

Many thanks

Derek

 

[HandySparks]

How long ago was the consumer unit installed?

 

[Darkwood]

A 30mA rcd will usually trip between 20mA to 30mA, just 1 computer can see a few mA sent down the earth wire (this is normal), it may also be the case that you have an intermittent fault, this is just educated guesswork over the internet with the info you have supplied and would of course need an Electrician out to confirm with meters if what we say is in fact what is causing the issue.

 

[Barry White]

Do not try and swap "fuses" as you call them it wont cure the problem and will in fact cause more. I would advise getting in an electrician in to look at the circuits.

 

[telectrix]

as a DIY approach, you could try unplugging half of the IT stuff and, using a 4/6 way extension lead, plug them into a socket on a different circuit.

 

[DerekBlakey]

Hi

I guess 20 - 25 years

Thanks

Derek

 

[Midwest]

That's not really modern Derek. Perhaps if you could take a few pics of your consumer unit and post here, the chaps might be able to advise you further.

 

[Octopus]

I suspect the mcb for circuit 3 is the problem. It's probably been running close to, or over its limit for years.

 

[DPG]

I'm with Darkwood and Tel - cummulative leakage from all the IT stuff tripping the main RCD. Daz

 

[DerekBlakey]

Hi Guys

Thanks for your advice.

I think what I am going to do in the first instance is us an extension cable from my office to plug it in to a socket on another circuit and see what happens.

If that does not work I gues its unplug everything and then put back one at a time.

I will let you know how I get on. I will probably attempt this tomorrow since I cant get on with a whole load of work if the power is constantly on and off.

Although , one thing I did forget to mention was the 750 UPS on my PCs.

Many thanks for youre time

Derek

 

[sean_ork]

I'll bet its the UPS

APC ?

 

[Octopus]

Hi Guys

Thanks for your advice.

I think what I am going to do in the first instance is us an extension cable from my office to plug it in to a socket on another circuit and see what happens.

If that does not work I gues its unplug everything and then put back one at a time.

I will let you know how I get on. I will probably attempt this tomorrow since I cant get on with a whole load of work if the power is constantly on and off.

Although , one thing I did forget to mention was the 750 UPS on my PCs.

Many thanks for youre time

Derek

That is a good step to take.

Please let us know how you get on.

 

[telectrix]

just thought. if it's an upfront RCD, that won't work.

 

[Octopus]

just thought. if it's an upfront RCD, that won't work.

I thought the MCB was tripping as well as the RCD?

 

[telectrix]

think he said the RCD tripped when he reset 1 of the MCBs.

 

[Octopus]

think he said the RCD tripped when he reset 1 of the MCBs.

Yup, but a knackered MCB could trip the RCD.

 

[telectrix]

true, ot he could be switching MCB on with all that IT etc. starting up at once.