I'm totally baffled !!??

[Torturedsole]

Hi All

New here !

So this has me stumped .

I'm currently renting my house privately and i asked permission to have smart meters installed as i currently have really old analogue ones . When the chap , who was from a subby of Scottish power , Turned up he plugged his socket tester ( cant remember the brand ) and he got the weird reading as i have gotten in the attached pictures ( the fluke one is my own , i have also tried 2 other ones ).
As you can see the red LED lights up even when the switch is off on the socket , but it isn't always present , some times its dimmer , sometimes its not there at all. For instance when i was taking these photos , at first it didn't light up , then after like 30 seconds or so it came on .
The installation has passed its inspection , i have the cert , and i asked the landlord to send someone to take a look to be sure and they said they hadn't see it before . Ive searched the net and i cant find any reason for this ??

Trouble is the subbie wont come out to fit the smart meters as they seem to think its massively dangerous ??

Any ideas ???

TIA !

 

[timhoward]

Is it like that in ALL sockets?
If the cooker switch has a socket on it pls try that one too (it will be a different circuit)
A picture of consumer unit, meter area and cutout (where supplier fuse is) might help too.

 

[snowhead]

So the Scottish Power subby thinks it's massively dangerous, pressumably did not carry out any other tests and walked away leaving the installation Live without a known explanation for the apparent fault??

It may not be dangerous but untill proven otherwise it should not have been left live.

And did the Landlord's Electrician arrive pretty quick and come to the same conclusion or have they not arrived yet?

 

[Torturedsole]

So the Scottish Power subby thinks it's massively dangerous, pressumably did not carry out any other tests and walked away leaving the installation Live without a known explanation for the apparent fault??

It may not be dangerous but until proven otherwise it should not have been left live.

And did the Landlord's Electrician arrive pretty quick and come to the same conclusion or have they not arrived yet?

He has been , chucked his meters on and said he cant find out why .
Also to add i think the guys the subby sends aren't spark's they just plug in the socket tester to check , i doubt they know how to use any other meters .

Ive got this off the recent test report for the house " Circuits are satisfactory . Problem with earth fault test reading too high on TT system . Exposed conductors on RCD enclosure . Cooker MCB 40a too high for a 6mm cable , RCD doesn't trip a 5 x fault current " And as a whole it received a satisfactory

 

[Torturedsole]

Is it like that in ALL sockets?
If the cooker switch has a socket on it pls try that one too (it will be a different circuit)
A picture of consumer unit, meter area and cutout (where supplier fuse is) might help too.

Yes all sockets , up and downstairs. (diff circuits)
No cooker socket

 

[littlespark]

He has been , chucked his meters on and said he cant find out why .
Also to add i think the guys the subby sends aren't spark's they just plug in the socket tester to check , i doubt they know how to use any other meters .

Ive got this off the recent test report for the house " Circuits are satisfactory . Problem with earth fault test reading too high on TT system . Exposed conductors on RCD enclosure . Cooker MCB 40a too high for a 6mm cable , RCD doesn't trip a 5 x fault current " And as a whole it received a satisfactory

Sorry… “exposed conductors….” And he gave it a satisfactory?

I take it he means there’s excess copper showing at the terminals, but can’t be touched because it’s inside an enclosure… so not actually “exposed”

40A is fine for a 6mm cable, generally.

And RCD not tripping is a C2. Potentially dangerous.


Now, the plug in tester…
I can’t quite see what the pattern of lights means, but green lights normally means good… Red light bad.

If the red light indicates a neutral/ earth fault, then that will still be there with the switch off at the socket, as the switch only breaks the live, not neutral conductor. (Some are double pole, but obviously not this one)

 

[pc1966]

He has been , chucked his meters on and said he cant find out why .

Looking at the tester photo (other site, sharper picture) I think the red LED shows N-E voltage. Normally that is quite low as N is linked to E somewhere (just where defines the TN-S / TN-C-S / TT systems). But in your case it clearly is not so either N is at an elevated voltage w.r.t. true Earth, or your E is somehow "livelier" than it should be.

Also to add i think the guys the subby sends aren't spark's they just plug in the socket tester to check , i doubt they know how to use any other meters .

Probably...

Ive got this off the recent test report for the house " Circuits are satisfactory . Problem with earth fault test reading too high on TT system . Exposed conductors on RCD enclosure . Cooker MCB 40a too high for a 6mm cable , RCD doesn't trip a 5 x fault current " And as a whole it received a satisfactory

Well it should only get satisfactory if those issues have now been fixed!

The very first point sound suspicious to me as a VERY poor / missing earth rod could result in the system CPC ("earth" conductor) being at enough of a voltage w.r.t. neutral to light an LED.

The RCD failing to trip is also worrying if it has not been replaced or another reason found and fixed. Personally you need to get back to landlord and get someone out who does find the reason for the high N-E voltage. At the very least measure the earth rod Ra value to confirm it is adequately low, and measure the N-E voltage to see if it is sane (handful of volts typically, probably no more than 10-15V if voltage drop is being met I guess).

 

[timhoward]

I had a hunch this was TT.
A non working RCD is a very big deal on TT systems and even more so in your case if the impedance is too high even for TT.
There is no guarantee a fault will disconnect the supply at the moment and this is a fire risk.
In short the installation needs looking at again prettty urgently by someone competent.
What area in Wales btw?

 

[Torturedsole]

Sorry… “exposed conductors….” And he gave it a satisfactory?

I take it he means there’s excess copper showing at the terminals, but can’t be touched because it’s inside an enclosure… so not actually “exposed”

40A is fine for a 6mm cable, generally.

And RCD not tripping is a C2. Potentially dangerous.


Now, the plug in tester…
I can’t quite see what the pattern of lights means, but green lights normally means good… Red light bad.

If the red light indicates a neutral/ earth fault, then that will still be there with the switch off at the socket, as the switch only breaks the live, not neutral conductor. (Some are double pole, but obviously not this one)

Yea , on my socket tester , there isnt actually a pic that show all 3 leds lit up , generally the 2 green is all good , then its either of the greens with a red indication reversed live/neutral . Which is whats throwing me , no idea what all 3 means

 

[Torturedsole]

I had a hunch this was TT.
A non working RCD is a very big deal on TT systems and even more so in your case if the impedance is too high even for TT.
There is no guarantee a fault will disconnect the supply at the moment and this is a fire risk.
In short the installation needs looking at again prettty urgently by someone competent.
What area in Wales btw?

I'm in Abergavenny .

Problem is hes signed it off as satisfactory , so the landlord is likely to laugh me off . Only way round it is to actually catch fire then i can say something

 

[timhoward]

Yea , on my socket tester , there isnt actually a pic that show all 3 leds lit up , generally the 2 green is all good , then its either of the greens with a red indication reversed live/neutral . Which is whats throwing me , no idea what all 3 means

My long range complete guess - a Neutral Earth fault in fixed wiring or a connected load (which would normally trip your RCD), and loose connection on earth rod.
That would lead to a basic tester thinking earth has too much voltage to be earth and cause the LED to glow.

 

[Torturedsole]

The test certs if that helps ?

 

[snowhead]

Did the "Smart Meter" person leave any paperwork saying it's "massively dangerous" or anything saying why they wouldn't fit the meter?
I'd be amazed if someone left paperwork saying the installation is too dangerous, but also left it live.

He has been , chucked his meters on and said he cant find out why .

And what does he propose doing about it?
Any paperwork?

 

[Torturedsole]

Did the "Smart Meter" person leave any paperwork saying it's "massively dangerous" or anything saying why they wouldn't fit the meter?
I'd be amazed if someone left paperwork saying the installation is too dangerous, but also left it live.


And what does he propose doing about it?
Any paperwork?

No to both.

the smart meter guy just rang his supervisor and told him , who in turn told him to walk away
And the landlords sparky came like 2 days later and he tightened a few terminations up and the led went out , so he thinks he fixed it , but like i said on the origional post , the leds dont stay one , they are random

 

[littlespark]

Normally, there is no voltage neutral to earth… so it’s possibly not an option on these testers.

Looks like VIR tails between cutout and meter which could do with being replaced, but that should be done if the meter is changed.

The test certificate doesn’t have a number for “points served”
How difficult is it to count light bulbs?

 

[OnlQQker]

You wouldn't happen to have an outside light tapped into that circuit by any chance?

 

[timhoward]

It looks as though this is a report completed after some of the concerns were addressed.
According to the report and pictures the cooker is now on a B32, there is no longer an RCD enclosure, and the (presumably) two RCD's are both operating within required times, assuming the 333 was a typo and should be 33 like it's neighbours.

The main thing that jumps out now, as the OP already mentioned is the earth electrode impedance is well above what I'd be happy with, mitigated by the fact that fault protection is being provided by the RCDs.

 

[Torturedsole]

You wouldn't happen to have an outside light tapped into that circuit by any chance?

There is an outside light , which may be tapped into it

 

[goasis]

The test certificate doesn’t have a number for “points served”
How difficult is it to count light bulbs

The tester apparently didn't even know what voltage he/she was doing the IR testing at, or any mention of how they've managed to get RCD test results when there's no RCD mentioned, and presumably don't know where to find max zs values in bs7671 as they are N/A as well.

 

[Dave OCD]

And all the circuit Zs readings are waaay below Ze value ?! Were these measured with all the bonding connected ?