Low Voltage problem...or so I thought!!

[Limbo]

Hi everyone. I'll try not to bore you too much but I'll give all the information that's relevant which hopefully will lead to a solution!!!

Lights in the whole house started to flicker a couple of days ago and didn't think much about it. My wife was cooking a cake (electric oven) and she said it seemed to be taking forever. I then investigated a few other appliances and the usual suspects the kettle, iron etc would cause the whole house to nearly stop working!! This isn't just a slight dimming of lights. It's now impossible to have the microwave on at the same time as say the oven because neither gets enough power to work. Add the toaster in at the same time and everything nearly stops.

Southern Electric came round to check the supply and it's as close to 240 as it could be. In the four years we've been here we've never had a problem with low electric and I haven't had any electric works carried out for some time. The CU is a Crabtree Starbreaker and is linked to a separate RCD which is on the wall (power supply comes in from overhead cables)

Any help would be greatly appreciated. I like my wifes cakes!!!!

Thanks

 

[luminaire]

It could be something outside of your premises.
Have your neighbours had a similar experience?
Has any work been carried out out on the cables or transformers near-by?

 

[Limbo]

We live in a semi-detached house and also have a detached neighbour on the other side. I've spoken to them both and neither of them seem to have any problems.

Interesting you should ask about any work being done though. Just remembered that about five days ago Southern Electric did put a new post up and cable which may link to our supply post. This was on Wednesday or Thursday though and this has only happened since Saturday!! Surely other people would be having the same problems though? Also, wouldn't it have shown up when SE checked the supply voltage to my house?? Don't know the answers to this unfortunately!!

 

[electronicsuk]

Did you turn on any of the trouble causing appliances when they checked the voltage? If there was no significant load on your supply then a problem could have gone unnoticed, although I'd like to think the DNO guys would check pretty thoroughly.

Could also be a problem with the tails at your CU or the meter, are there any signs of excess heat at either of these locations?

 

[Limbo]

Just felt all the cables around the CU and Meter and no heat at all.

As for switching any appliances on whilst he was checking I'm not sure. I don't think he did. I was with him when he was reading the voltage and that's when he said that it was a very good supply (just under 240) and he explained that it would have to be much lower before SE took any further action.

I did turn the toaster on and off just to show him what i meant with the lights and he acknowledeged that things weren't right. I don't think at this point he was actually testing it though (different rooms so don't know for sure) he didn't actualy ask me to turn any appliances on but i just did it to prove that there is a problem. The next thing he suggested was to leave it afew days and if it hadn't sorted itself out then they can attach a voltage recorder for a days and see if it's an external or internal problem. Worth doing?? Does this sound like a supplier problem rather than an internal problem. I don't want to get a sparky if it's out of their hands!!

 

[sparkydude]

It is possible to be a problem with your fuse box but unlikeley . Are you confident dealing with electrics? if you are not then i suggest you get an electrician to have a look for you to see if there is any loose connections on the mains switch terminals, meaning that under load ther volatage drops as it is not making a good contact . Or as you say it could be on southern electrics side. Did they have the front off the fuse box or did they test from their equipment?

Nick

 

[Limbo]

I'm pretty handy and I've done a fair share of electrical jobs so more than happy to check connections. Turn off the mains (RCD on supply board) and take the cover off the fusebox. Check all connections and fuses??

The engineer connected all his kit to the main board and he didn't touch the fusebox at all.

 

[sparkydude]

Yes thats what you need to do really, just remember even with the mains rcd off (if its in the board ) there will be live parts exposed by removing the cover. If its as bad as you say then it might be easy to spot as the connections may well have overheated quite dramatically.

Nick

 

[Limbo]

The engineer attached all of his kit to the main board. He didn't touch the fusebox.

I'm happy to check the connections. Do you mean fusebox? The engineer checked the main board so that should be fine!

 

[Limbo]

The engineer attached all of his kit to the main board and didn't touch the fusebox.

I'm happy to check connections. Do you mean on the fusebox? I'm assuming the engineer would've checked the main board!!

Just to show you how bad it is at the moment I've had to stop the dishwasher, turn all but one light off and now my connection to the internet and computer are running properly!!

 

[sparkydude]

sorry yes i mean at your fusebox, if your connections are tight and theres no sign of anything untoward then it must be on there side and could be something simple like the meter is faulty and has a high resistance on it so the power cannot get through under load.

Nick

 

[bongos]

If you end up taking the front off the CU/fuse board then take a couple of pics.

Might be worth posting a picture of your service head/incoming supply too.

 

[Limbo]

Right then...the saga continues!!

I've taken the cover off the CU and checked all the connections. There was one slightly loose screw but once tightened hasn't changed anything in relation to this problem. First time I've had this cover off and everything looks in good condition and all nice and tight.

Fusebox

• Limbo
• 7 Oct 2008
• 1

Here is the supply board...

Supply Board

• Limbo
• 7 Oct 2008
• 1

I spoke to Southern Electric again and they are still talking about putting in a Voltage Recorder to see if that can find the problem. Could take a few days though and here i am trying to look after my 2 year old with hardly any power to cook, clean etc....

Thanks for eveyones replies so far!![/img]

 

[electronicsuk]

Potentially dangerous advice removed
Moderator 9

 

[BS3036]

I have been itching to suggest using a multimeter to check the voltage at various sockets, but concerned that using a multimeter to measure mains is not risk free. However it occurs to me that this Plug-in Mains Power and Energy Monitor may be just what you need, at least to establish the problem.

I have one, and love it, and at its current special offer price of £10, it seems too good to miss. So you could monitor the mains voltage at any socket in your house (risk free) to see what sort of problem you have.