Earth Loop Impedance Test and problem with power supply

[Maverick777]

I can see the yellow and green cable from the power supply that enters the house. But none near the consumer unit in the house or the garage or gas supply, which is a worry as the cable from the consumer unit runs through the gas meter box to the garage.

 

[telectrix]

well, if the supply is PME, then your Ze should be lower than 0.35, nothing like the 300 odd you mentioned. something fishy here .

 

[Maverick777]

What do you mean that we have 2 power company supplies?

 

[Des 56]

Not sure I can see the earth, but it is PME certified with a sticker.

My eyesights not up to much these days but that sure as damn it looks like a green/yellow in that pic

It is very possible that if there are services requiring bonding they will be present,the terminal should only be used when the requirements are met


edit Just seen the other picture with the second supply?
It gets interesting

 

[Engineer54]

I can see the yellow and green cable from the power supply that enters the house. But none near the consumer unit in the house or the garage or gas supply, which is a worry as the cable from the consumer unit runs through the gas meter box to the garage.

Are you out in the country as opposed to being in a village or town?? I would almost certainly be getting back in touch with your power company and asking if PME earth connection is available at your location. If not, then you will need to install your own TT system by means of driving a rod or rods into the ground in your back garden preferably. You will NEED to bond your incoming water/gas services too as close to there entry point as possible (within 600mm) It certainly looks to me as if you have no means of earthing or bonding to your property. Your electrician should have been far more conserned about this than renewing your CU, that could have been done at a later date!!!

 

[Engineer54]

Not sure I can see the earth, but it is PME certified with a sticker.

My eyesights not up to much these days but that sure as damn it looks like a green/yellow in that pic

It is very possible that if there are services requiring bonding they will be present,the terminal should only be used when the requirements are met


edit Just seen the other picture with the second supply?
It gets interesting

Can't see anything coming out of either of the 2 cut-outs myself either...lol!!

 

[Engineer54]

oops just seen post 20!!


Seems you have 3 power company cut-out positions, not going to even ask how. But the cut-out where the meter is definitly has a PME connection to it. Now where that earth conductor goes, i haven't a clue, can't see any sign of an earth or bonding conductor in any of the other photo's

 

[Des 56]

I wrote the reply below but didn't post in case I made an idiot of myself,but I am less convinced (being the idiot that is)

This must be a real off day for me

I just looked through the 2 posts showing the pics and can now count 3 cut outs,I gather there must be 2 supplies and 2 cut outs and one home made jobbie

Perhaps

 

[Engineer54]

What do you mean that we have 2 power company supplies?

You seem to have a power company fuse cut-out in an external box, in your house by the fuse board and another in the garage by another CU.... 3 power company cut outs, ...So how come?? Most premises will have only one!!! lol!!

 

[Maverick777]

I believe the cut out is correct by the external box, the one by the fuse board and in the garage where installed by Bob the Builder many moons ago. I've looked at the one in the garage and it was bridged by some 15 amp fuse wire. So I assume it was not a bona fide electrician. Could this be the cause of the problem?

 

[Maverick777]

I think the two extra cut outs are the supply to the garage and not correct for the job.

 

[Engineer54]

Has your electrician looked at these cut-outs, ...come to that, what did the DNO have to say about them. That one by the main fuse board is certainly DNO concentric cable. Not many general domestic electricians would be touching such cable...

As for being the cause of your problem, i doubt it, but who knows where and how these supply cables have been connected to the incoming supply!! lol!!

EDIT... Can you isolate the garage CU from the main fuse board??

 

[Paul.M]

I've got a few things to say about this thread:-

First I would like to thank Maverick777 for actually posting up photos to give us all an in-depth picture of what your talking about. I/we wish that more people like yourself asking for help/advice put in as much effort as you. Well done.

A little praise to E54 that he didn't have a pop at me for suggesting that "we" (not him btw, all in this together) were crossing a line. Me and E54 have crossed swords in the past (and not like that) and its great to see us lot coming together to help out a home owner good enough to give us the info that we need.

Again to Maverick777, thanks for a new saying that I will use "cowboy cu to garage" love it and I will be using it in the future.

Btw get a proper sparky in to look at this mess. A cu change won't help your problems looking at the photos.

 

[Maverick777]

Hi,

It would be great if any of you were in the Blackwood area of Gwent. Why are some of you thinking that our house is supplied by two power companies as one meter in post 20 is of the gas and one the electric. Is this what you meant?

Thanks

 

[Maverick777]

This is what Western Power engineer said after a visit:-

Hi both,
When I visited again on Saturday morning the cause of the crossed polarity was obvious.When the RCD was installed the tails in the grey twin cable were connected red-black in the top of the consumer unit.This particular type of unit needs to be black-red.It is probable that we removed the external fuse to enable the RCD to be installed and on completion the fuse was replaced.However polarity checks showed reverse polarity.To correct this the tails were reversed on top of the external cutout and this cured the problem.At this stage there was no electrical danger and it stayed that way until the shower developed a fault last week and the crossed tails were spotted by Lloyd.
We have now reconnected the tails the correct way round.We also carried out trip testing on the RCD and found it faulty at required sensitivity,also it trips when the consumer unit DP switch is operated.This unit needs to be replaced.
The consumer unit is also old school and could be upgraded with a combined segregated unit but Beesleys will advise what options you have.
We will pay for the visits on Thursday and Saturday ,the remaining work is your responsibilty to settle directly with your Contractor.
regards

 

[GLENNSPARK]

Apart from the reverse polarity has the electrician said why you need a board change?

another example maybe of "electrician" condemning a C/U without any valid reason maybe?...lol.....reminds me of this PIR we got for this rented a bit back from this "sparky"..lol.......sparky that gave gas and water bonding using a single continuous 10mm conductor as a (1)....lolffs....

 

[GLENNSPARK]

This is what Western Power engineer said after a visit:-

Hi both,
When I visited again on Saturday morning the cause of the crossed polarity was obvious.When the RCD was installed the tails in the grey twin cable were connected red-black in the top of the consumer unit.This particular type of unit needs to be black-red.It is probable that we removed the external fuse to enable the RCD to be installed and on completion the fuse was replaced.However polarity checks showed reverse polarity.To correct this the tails were reversed on top of the external cutout and this cured the problem.At this stage there was no electrical danger and it stayed that way until the shower developed a fault last week and the crossed tails were spotted by Lloyd.
We have now reconnected the tails the correct way round.We also carried out trip testing on the RCD and found it faulty at required sensitivity,also it trips when the consumer unit DP switch is operated.This unit needs to be replaced.
The consumer unit is also old school and could be upgraded with a combined segregated unit but Beesleys will advise what options you have.
We will pay for the visits on Thursday and Saturday ,the remaining work is your responsibilty to settle directly with your Contractor.
regards

surely the option here would be to replace the RCD....if the C/Us good for continued service...then just being "old school" is not acceptable reason to replace it is it?....as long as its in good order (IP)...and disconnection times are being met......

 

[Engineer54]

Hi,

It would be great if any of you were in the Blackwood area of Gwent. Why are some of you thinking that our house is supplied by two power companies as one meter in post 20 is of the gas and one the electric. Is this what you meant?

Thanks

No, you just have a very weird set-up there with the amount of cut-outs you have in your installation. I'm guessing that the cable shown supplying the main fuse board was once where the meter was, and has now been moved to an external position, but have used the old existing cable to continue supplying the fuse board. Haven't a clue how the one in the garage got there, but suspect that is now being used as a sub-main from the main fuse box. As i say, very wired that the cut-outs have been left in place by the power supply company, they normally remove them when any changes have been made to there installation...

Sorry, but i'm rather a long way from your neck of the woods... lol!!

 

[Paul.M]

another example maybe of "electrician" condemning a C/U without any valid reason maybe?...lol.....reminds me of this PIR we got for this rented a bit back from this "sparky"..lol.......sparky that gave gas and water bonding using a single continuous 10mm conductor as a (1)....lolffs....

You posted at the same time as the op, post 35.

He's got it in writing from the electricity board! You need a new cu lol.

Again thanks for the pics but honestly get a proper electrician to investigate your electrics. I'm not in your area but I wish I was. Looks like an interesting case.

 

[GLENNSPARK]

that mem C/U may be hard to get an RCD for as they use an RCD incomer in those.....