Fault find on ring circuit

[Jabbajaws]

Hi, ive had a phone from a disabled gentleman today, who explained to me that he had plugged his microwave into his kitchen socket and BANG! the lot went off.

He says that the only place that there seems to be a problem is the kitchen area. The lounge is still on and no power circuits are working at all in the kitchen area. Everywhere else, he says, the circuits are working as normal.

He has had a friend have a look and has 'exchanged' the breaker for one of the same type, from another circuit on the same CU.

Now this info has been given to me over the phone by a customer, so l cannot verify that everything he says is correct, until l get there and check it on Saturday.

What confuses me slightly is that he says that the kitchen is a ring circuit and that no other sockets are working and that he has had to run extensions from the other room.

Now surely if the microwave has damaged the socket which he has plugged it into, and if his info is correct, then that would have split the ring possibly into 2 radials and the rest should have power supplied to them.

Calling all veterans, is there anything that l should be aware of, that a DIY-er could possibly have done that would cause this to happen?

Im worried that with him being disabled that he has had friends' performing work or doing things for him in his house.

I cant think of a reason personally for the other kitchen sockets to be off (unless he has got his explanation totally wrong).

 

[Des 56]

I am a little confused with your queerie

He may just have a separate kitchen ring

 

[trev]

I don't see how plugging in a faulty appliance or a damaged socket could have split a ring into 2 radials mate and the simple fact that he's disabled doesn't make it any more likely that DIY Dave has been round although the bit about swapping an MCB does seem to suggest that's likely.
The socket could be damaged and that's what has caused the circuit to bang. No real way of knowing till you get there really.

 

[telectrix]

never believe what a customer says. he is usually 1. misguided, or 2. lying. go to the job with an open mind. first check for signs of his friend bodging, then trace the problem logically.

 

[Jabbajaws]

I am a little confused with your queerie

He may just have a separate kitchen ring

Well Des im totally confused with what he said over the phone. It sounds like the kitchen is on its own ring from what he was saying but l cant really expect him to know that. It sounds like the socket has exploded, though again l cant verify that until l get there.

 

[Jabbajaws]

never believe what a customer says. he is usually 1. misguided, or 2. lying. go to the job with an open mind. first check for signs of his friend bodging, then trace the problem logically.

Thanks Teletrix, the voice of experience as usual. I still consider myself a novice at this as l only work part time at moment and appreciate any advice l can get...

 

[Des 56]

Straightforward problems and causes can become very complicated when described over the phone by non electrically minded folk

Take what is said with a pinch of salt and please let us know what was the outcome

 

[Jabbajaws]

Thanks Des will do and also Trev (wasnt being ignorant)...

 

[trev]

Thanks Des will do and also Trev (wasnt being ignorant)...

Didn't think you were mate, it's often difficult to reply to every post. Don't worry about it, we cool

 

[Tiny Spark]

Having the kitchen on a ring is not unheard of.
After all most large appliances are found in the kitchen!
Why has someone changed the breaker?
From my experiences of these sort of things regarding kitchens they have usually either overloaded the circuit or got water on a socket and blown it.
Has he tried unplugging all appliances and resetting the breaker?
If so then you know the problem is with the circuit and not his appliances.

 

[7029 dave]

ditto post 10 good advice

 

[Octopus]

The only way to establish whats going on is to go to the clients house, and then do your job, which is listen to the client and then see for yourself.

Speculating on here won't help.

 

[sbelec]

I would suggest great care and look for junction boxes, recently had a similar experience but the "kitchen fitters electrician" had run a figure 8 circuit. The ring was broken and a junction box fitted with the 2 ends of a "second" ring (so 4 x 2.5mm cables) and in my case a set of burn't cables (lost all the nuetrals) and ended up with 2 radials working and a ring not working having lost nuetrals but the sockets were still live.
It could well be a radial circuit off a ring with multiple sockets - again not uncommon from DIY'ers - then you have a 32 amp mcb fitted protecting a number of circuits leaving overloaded cables and the weak point is the junction box.

I feel a good start point would be to investigate if any other working sockets are on the kitchen MCB then do a full test of the circuit as if you were doing a condition report.

Again extreme caution and test every cable as you go along because you could have lost the nuetral circuit and not the live, best of luck but hope you didn't give him a price because if its a "connector block" issue it could take a long time to find and resolve.

 

[robsparky1975]

On this type of a call,there is no need to overcomplicate things,it may well be something really simple,make sure you have a replacement socket with you and test equiptment,you could be there 5 mins or 2 hours if someone has been fiddling with the wiring but unless proven otherwise the installation may have remained untouched in decades when the original sparks wired it(no cereal packet sparks in those days).Let your eyes and other spidey senses tell you if something is untoward.

 

[Jabbajaws]

It turned out the lounge and kitchen were all part of one whole ring circuit, with multiple faults on several locations.

The gentleman described having work done 15-20 years ago, by a guy who was not a sparky, and he paid him £15 per hour for this piece of mess that ive had to sort out. They defo saw the disabled guy coming.

Over 5 socket outlets had loose conductors, with another 2 incorrectly wired.

The ground floor ring circuit (the one in question) had been diverted all the way upstairs to feed the hall way socket, which spured off into a little bedroom and then back downstairs again.

There were two bedrooms, both of them were on separate radials protected by 16A MCBs (strange as one would have done it).

Once id screwed all outlets tight l performed end to end tests:

L-L open circuit
N-N 0.42ohms
E-E 1.04ohms

Ive looked everywhere l possibly can for the break in this circuit on the L-L side and cannot find any more sockets, so l was thinking possibly junction box under floor?

It was only after l asked the disabled guy this that he explained that the COWboy had sawed through a cable at the time and that he had repaired it and put it under the floor, but didn't have a clue where.

IR tests were fine 183Mohms on L-E, 182Mohms on L-N and 183Mohms on N-E

Time was getting on and l couldn't leave this guy with no power so l de-rated the fuse from 32A to 16A and turned back on.

Zs readings all ok, with highest on ring being 0.63ohms. No RCD fitted as BS 3036 board with MCB adaptable breakers.

Not the worst ive ever seen but l couldnt believe how these guys had creamed him for all this money and then done a job like that. Its disgraceful.

Anyway moan over. Thanks for everyone's input. :30:

 

[Tiny Spark]

Just goes to show you never know what you are going to find!
So whats he doing with it long term?

 

[SPARTYKUS]

Just goes to show you never know what you are going to find!
So whats he doing with it long term?

Keep resetting the MCB !

 

[Tiny Spark]

Did you do a full ring main test btw?
May help to identify the location of the line break.