Experiencing volt-drop within household

[bridav]

Hi All,

I am not a qualified electrician - please be gentle!

I had renovation done to my house last October which included a complete refitted kitchen. The new kitchen included a new Neff double oven in which has been working like a charm since last it was installed (including both ovens being on at the same time!).

Suddenly, yesterday the double oven has decided to stop working, checked the distribution board and nothing has tripped. I have tried getting in touch with the electricians that did the installation, but has failed to get back in touch. Therefore, decided to investigate the matter further. I put my multi-meter over the live and neutral terminals on the oven and it read 150V AC, I have checked the outgoing voltage at the MCB which read 240V AC. I thought I may either have:

1. a bad switch
2. a bad MCB
3. a bad connection
4. may be an earth leak

I have tried changing the switch and the MCB, no change to the volt reading [whilst disconnected from the oven]. I have tried tightening the terminals within the distribution board in case of loose connections, no such joy!

Other observations, I noticed that the cable exiting the oven is BLUE and BROWN whereas the cable leaving the distribution board is RED and BLACK. I cannot find the join for this cable as I fear it may be tucked behind the newly plastered walls and ceilings!

Any assistance or information on how to rectify the above volt drop without punching holes about the house would be much appreciated.

Many thanks,
Brian

 

[Darkwood]

Welcome to the forum

 

[Pete999]

Did the "Electrician" leave you with any certification, did the company belong to any of the Schemes NICEIC,NAPIT STROMA? it could be that the "Electrician" was in fact Kev the Kitchen fitter, ergo not an Electrician. I could be that he connected your oven / cooker to a cable that is far to small for the intended use you require at present, I'm not saying this is the case, as I'm only going on the information you have given.

If the company doing the renovations were allied to any of the schemes, your first port of call would be to whichever scheme they belonged to, if not, then call a local registered Electrical Contractor and ask them for an assessment of your problem. Good luck with your investigations I hope it turns out to be a minor problem easily rectified.

 

[gazdkw82]

Is it on a fused switch which should be in the wall somewhere? If so check all terminations are good and check fuse.

The oven itself may have a fuse.

sounds like power to the cooker is good

always make sure you cut the supply at the cu via the mcb or better switch the main power switch off if you don't have the correct tools to make sure supply is in isolated.

 

[Octopus]

You need to locate a local competent spark.

Where are you based?

 

[gazdkw82]

How on, you've changed an mcb?

if your not competently experienced I wouldn't suggest taking on work like that. It can kill you

 

[David M]

Its best you get a qualified sparky in to check it out for you. The oven worked fine for a short period, then just suddenly stopped working properly and you are certain its not the oven?

If its definitely not the oven then there must be a fault that's appeared on the circuit supplying it. If all else is ok, to get such a dramatic voltage drop can only indicate a fault of some kind.

No offense, but a decent spark will be able to verify your voltage drop, do other fault finding tests and then proceed to try and find the culprit of the problem. But be prepared as it may indeed require some disruption. Unfortunately this may mean searching for and "digging" out any hidden joints.

 

[7029 dave]

Is it on a fused switch which should be in the wall somewhere? If so check all terminations are good and check fuse.

The oven itself may have a fuse.

sounds like power to the cooker is good

always make sure you cut the supply at the cu via the mcb or better switch the main power switch off if you don't have the correct tools to make sure supply is in isolated.

Not at 150v it's not.

 

[gazdkw82]

True.

how did he measure the voltage? Line to earth? Neutral to earth? Just the neutral? Just the line?

 

[7029 dave]

True.

how did he measure the voltage? Line to earth? Neutral to earth? Just the neutral? Just the line?

Looking at his post he measured across L N of cooker.