Intermittent incoming supply.

[mktdeeping]

I was called to look at a job for an elderly couple where the oven supposedly tripped the supply and then after a few minutes the supply came on again. An engineer was called to check the oven and it checked out ok. A few days later when the oven was on the power went off again. No power to lights and sockets. I checked the RCD and mcb’s etc. and none had tripped. I put my Megger on the incoming tails and found that there was no incoming supply. A few minutes later it came back on again. There were no loose connections in the consumer unit or at the main cut out or smart meter.
Has any one got any suggestions what could be causing this?

 

[Fleeting]

Could be an issue within the service head or external to the property. You need to contact the service provider.

 

[binky]

I was called to look at a job for an elderly couple where the oven supposedly tripped the supply and then after a few minutes the supply came on again. An engineer was called to check the oven and it checked out ok. A few days later when the oven was on the power went off again. No power to lights and sockets. I checked the RCD and mcb’s etc. and none had tripped. I put my Megger on the incoming tails and found that there was no incoming supply. A few minutes later it came back on again. There were no loose connections in the consumer unit or at the main cut out or smart meter.
Has any one got any suggestions what could be causing this?

phone DNO to report a 'dangerous situation' they should be with you in about 2 hours.

 

[NozSpark]

It's probably a failing joint in the supply cable.... you need to call the DNO

 

[UNG]

With faults like this I find it useful to speak to some of the neighbours to see if they are having similar problems with the electricity supply
Also doing some loop tests L - N and L - E and if your meter will do it an N - E loop test is also worthwhile as it can give a good indication of whether you have a fault within the premises or external DNO fault
With the recent adverse weather conditions it is possible that a pavement link box or buried joint is on it's way out the usual giveaway is if you notice a small patch of non frozen pavement in an otherwise frozen pavement

 

[Murdoch]

can you hear anything coming from the service head?

 

[mktdeeping]

I was called to look at a job for an elderly couple where the oven supposedly tripped the supply and then after a few minutes the supply came on again. An engineer was called to check the oven and it checked out ok. A few days later when the oven was on the power went off again. No power to lights and sockets. I checked the RCD and mcb’s etc. and none had tripped. I put my Megger on the incoming tails and found that there was no incoming supply. A few minutes later it came back on again. There were no loose connections in the consumer unit or at the main cut out or smart meter.
Has any one got any suggestions what could be causing this?

A quick update on this....DNO came out and after a quick wobble of main cutout and jiggle to tails they said they couldn't see a problem and to contact the service provider. The service provider are arranging to come and check the smart meter. £90 if no fault found.... watch this space.

 

[mktdeeping]

With faults like this I find it useful to speak to some of the neighbours to see if they are having similar problems with the electricity supply
Also doing some loop tests L - N and L - E and if your meter will do it an N - E loop test is also worthwhile as it can give a good indication of whether you have a fault within the premises or external DNO fault
With the recent adverse weather conditions it is possible that a pavement link box or buried joint is on it's way out the usual giveaway is if you notice a small patch of non frozen pavement in an otherwise frozen pavement

Ze, Zs and loop tests all ok.

 

[Sharpend]

Is this going to be the first trial test of supplier isolating supply from afar with aid of Smart meter? A Sign of things to come?????

With caution I watch this space.

 

[mort2376]

Put a voltage logger on the system and record for a week. This will give you positive data to go back and say "Oi DNO, NO !"

Unless the fault happens when they are there the dno can't identify it. That's why it can take months of power cuts before a faulty cable blows itself apart enough for them to locate the break.

 

[UNG]

Put a voltage logger on the system and record for a week. This will give you positive data to go back and say "Oi DNO, NO !"

Unless the fault happens when they are there the dno can't identify it. That's why it can take months of power cuts before a faulty cable blows itself apart enough for them to locate the break.

Easy to suggest and easy to do if you happen to have one but I doubt many electricians have a voltage logger as part of their test kit

 

[mort2376]

True, but they can be hired if its the only way to prove a point and get something done. There is a firm near me who I've used a few times £90 plus vat for 7 days.

Come with the software for the results to.

 

[Kot]

Is this going to be the first trial test of supplier isolating supply from afar with aid of Smart meter? A Sign of things to come?????

With caution I watch this space.

Or a Hacker lol

 

[UNG]

True, but they can be hired if its the only way to prove a point and get something done. There is a firm near me who I've used a few times £90 plus vat for 7 days.

Come with the software for the results to.

I would agree but the customer in the OP's post states an elderly couple who may not have much money to throw at the fault / problem

Where voltage issues are a concern my local DNO's will put there own logger in at no cost if made aware of potential network problems

 

[mort2376]

I would agree but the customer in the OP's post states an elderly couple who may not have much money to throw at the fault / problem

Where voltage issues are a concern my local DNO's will put there own logger in at no cost if made aware of potential network problems

So does mine but it does appear to be hit and miss. I had them out to a rewire last weekend where I was measuring incoming supply to be 254v and it had blown the board on the boiler.

Our regs say 253 maximum. Speaking to the guy who came out he said they work to 251 maximum.

Think it's all down to where you are in the country and if your DNO can be bothered !

 

[UNG]

So does mine but it does appear to be hit and miss. I had them out to a rewire last weekend where I was measuring incoming supply to be 254v and it had blown the board on the boiler.

Our regs say 253 maximum. Speaking to the guy who came out he said they work to 251 maximum.

Think it's all down to where you are in the country and if your DNO can be bothered !

Never had a problem when dealing with ENWL and not just local to me but across most of their patch and similarly with SP Energy Networks
I find a lot of the time it is how you communicate with them and how knowledgeable you appear to be as to what you get from them

When I last reported an excessive voltage issue to ENWL they put a voltage logger for 10 days and while it recorded supply voltages close to the maximum it never peaked above 253v while the logger was installed. The big problem these days is the solar feed in which can cause higher network voltages which are difficult to control

If a boiler board failed that would suggest that a spike well in excess of the 254v had occurred, had a job many years ago where there was a network fault that caused a spike of 1100v for about 10ms every week to 10 days that some power analysers were not sensitive enough to pick up, that was causing allsorts of appliaces to fail

 

[mort2376]

1100v yep that would blow a few things up. It may have been a fluke with the boiler but the fault code is excessive voltage and it won't reset.

Highest I've ever found was 259 constant. ENWL came out measured it and said. Yeah I'll go and turn the transformer down lol.

It's true if your honest and decent with them they usually are with you.

I got a jobs worth once who wanted all my details as I had cut the seal on the main fuse to pull it to change a cu and they had wired up next door through the same fuse ! Apparently I had changed the wiring as they would never do it like that ! Lol.