Fuse Board and Appliances Buzzing

[themelon]

Hi,

I have recently encountered a problem a certain times of the day where appliances such as TV, Kettle and PCs have been buzzing, I have also noticed that the Consumer Unit is buzzing at the same time. This mainly happens in the morning when very little has been on.

I have unplugged all items in case it was a faulty item and the consumer unit still buzzes.

At random times it will go off for long periods even days. I have had an electician round, sods law it was not buzzing. He did some checks and said everything seemed ok.

The buzzing seems to come from the main on/off switch on the consumer unit and it only does it when either of our 2 ring mains are on.

Any ideas, and any ideas why the buzzing is also heard by applicances on two seperate circuits?

Thanks

 

[JohnD]

show us a photo of the CU with the door open (but the cover still fixed) it will save a lot of questions.
//www.diynot.com/forums/viewtopic.php?t=129539

If you show the various cables around it, and the meter, and also a sample socket (the one for the kettle) that will give more clues.

I presume your electrician checked for anything loose.

Next time it happens, give the CU a knock with your knuckles.

 

[themelon]

He checked for anything loose. Says it was all ok. He didnt check all sockets though but ran some tests on a gadget which they all passed. Is it worth me check each socket for any loose connections.

Do you want to see the wires inside the consumer unit, it has a little brown cover on the front screwed in with thumb screws and a larger cover which is screwed on which exposeds the internal connections. Also do you need a photo with the socket front uncrewed to see the wiring for the kettle or just whats plugged in?

Cheers

 

[mattylad]

Perhaps the wife has misplaced her rabbit?

 

[JohnD]

no need to expose any internals yet (but you can if you like and can do it it total safety)

the thumb screw fuse cover is OK to remove

it will give us an idea of age, condition and quality.

 

[securespark]

Does it still buzz with all electricity off (CU main switch)?

I know you say the guy checked for loose connections, but what you say about it buzzing when there's a few things on means it could be a loose connection arcing under a heavy load.

 

[themelon]

It doesnt buzz when the main switch is off.

It also doesnt buzz when the heating, downstairs lighting, upstairs lighting and cooker circuit are on. Only when either ring main is on, even with nothing plugged into the ring main at all. It hasnt done this before sunday, nothing has been changed.

Only thing I can think of is a loose connection somewhere, that for whatever reason only occurs at certain times, When the check was done no buzzing, so appears as no fault. Bizareley its seems to go off alway when the house is warm!

I may up some of the floorboards and check some of the junction boxes, maybe see if any walls are damp or something.

 

[JohnD]

how about the photos?

the place that the noise is coming from is most likely where the fault is.

when the house is warm heating appliances will be off.

 

[themelon]

Will try and upload the photos later, when the damn weather is light enough to get a decent pic!

Sounds like it is coming from the main switch where the wires from the meter connect in. Would this buzz feed down to other applicances like the kettle, TV, Microwave, PC that are plugged in as they buzz too.

Would it be possible a fault on the network is causing this? As it doesnt appear to be related to load, just the fact that either ring main is on.

Cheers.

 

[themelon]

Below are the pics of the Consumer Unit and the Socket where the kettle is plugged in.

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• themelon
• 10 Jul 2008
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• themelon
• 10 Jul 2008
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• themelon
• 10 Jul 2008
• 1

 

[JohnD]

It might be the RCD at the RHS. that type with the partially-rotating lever is obsolete now, I remember hearing from someone who got a conversion kit from MEM to fit a modern RCD in its place.

If, when it is buzzing, you put your finger on the plastic casing of the RCD and press hard, see if it stops, or if you can feel it vibrating.

Also, see if the RCD is still working - it will have a "T" or "Test" button on it, when it trips, the lever will rotate about a quarter of a circle and you have to turn it back to reset it to "on".

I suggest you do it fairly early in the day so that, if it trips and will not reset due to age, you have time to do something about it.

Do you test it at least quarterly, or better, monthly? If not, it might stick "on" and fail to trip in an emergency.

Also, get yourself a hard, non-conductive prodder such as a large plastic knitting needle, and press it against things that you suspect of buzzing. You may be able to feel what is vibrating. It is even more effective if you grip the prodder in your teeth, as you will hear it.

If it is the RCD vibrating, it might be trying to trip when you have an appliance switched on with an earth fault. this is likely to be a watery appliance such as kettle, immersion heater, washing machine or boiler. Or sometimes a heating element such as an oven.

 

[themelon]

Thanks very much for the info, I will wait until it starts buzzing again and give those ideas a try.

The Test Button does still work and the unit trips off and the buzzing stops. I did generally test it every couple of months and it also trips when bulbs blow.

 

[kai]

That RCD looks like an old Voltage Operated type to me - it is worth getting it replaced with a current operated RCD if thats the case.

 

[securespark]

Also, get yourself a hard, non-conductive prodder such as a large plastic knitting needle, and press it against things that you suspect of buzzing. You may be able to feel what is vibrating. It is even more effective if you grip the prodder in your teeth, as you will hear it.

John, I'm not knocking your idea, I think it's brill, but I can just picture the OP rushing round the gaff with a long piece of plastic in his north, prodding things with it...

 

[JohnD]

Doubly brill.