Large Volt Drop in ring circuit

[Andy]

Hi Folks
This is my first post, but I've been reading many posts over the last few months and have found this forum very informative and some times very humorous, Thank you all.

I have recently come across a problem whilst doing some PAT testing for a customer that has left me confused. Although this is nothing to do with PAT testing it was my PAT testing meter that highlighted the problem when I plugged it into a socket.

The property is a 4 year old Timber barn and the loft has a small ring circuit with a spur off it feeding a socket below for a small telly.

My problem is that all of the sockets are only giving voltage readings of 60v but the reading for the circuit at the CU is the standard 240v
The only thing that I can think of is that when building the property someone has banged a nail through a cable somewhere.
I have been round all of the sockets and checked connections etc and found nothing obviously wrong.
When I mentioned it to the customer he said don't worry its probably been like it for ever and the sockets only supply low voltage stuff anyway.

Well I am concerned that its wrong and there is possibly a nightmare waiting to happen.
Im thinking of contacting the customer and trying to get him to let me rectify the problem
Is there anything else it could be?

I await your reply's with baited breath

 

[7029 dave]

All I will say is at 60v, nothing will work. Impossible.

 

[davesparks]

All I will say is at 60v, nothing will work. Impossible.

Nothing is impossible, but could be highly unlikely. Depending on the input range of switch mode power supplies it could be possible for electronics to function, but that does of course assume that this measured voltage is the open circuit voltage and not the result of a load in series with a high resistance connection.

 

[static zap]

@ buzzlightyear
Does the "Lightening" Icon (that appears to LH-side of main a-b display )
on a Fluke 1653b indicate its within it operationg range
of 100 V – 265 V ac, 50/60 Hz ?

 

[Specialist]

wjat fault are you expecting to find in the CU connections? Or is it a random guess?

Did you measure the 60V open circuit or with any load connected?
Did you carry out an earth fault loop impedance test of the circuit?
Did you observe any appliances working correctly whilst plugged in to an affected socket or do you only have the customers word for it?

Too many questions Dave, he wants answers but not the questions that lead to the answers.

 

[davesparks]

Too many questions Dave, he wants answers but not the questions that lead to the answers.

If there are no questions, then how can there be answers?

 

[Octopus]

Hi Folks
This is my first post, but I've been reading many posts over the last few months and have found this forum very informative and some times very humorous, Thank you all.

I have recently come across a problem whilst doing some PAT testing for a customer that has left me confused. Although this is nothing to do with PAT testing it was my PAT testing meter that highlighted the problem when I plugged it into a socket.

The property is a 4 year old Timber barn and the loft has a small ring circuit with a spur off it feeding a socket below for a small telly.

My problem is that all of the sockets are only giving voltage readings of 60v but the reading for the circuit at the CU is the standard 240v
The only thing that I can think of is that when building the property someone has banged a nail through a cable somewhere.
I have been round all of the sockets and checked connections etc and found nothing obviously wrong.
When I mentioned it to the customer he said don't worry its probably been like it for ever and the sockets only supply low voltage stuff anyway.

Well I am concerned that its wrong and there is possibly a nightmare waiting to happen.
Im thinking of contacting the customer and trying to get him to let me rectify the problem
Is there anything else it could be?

I await your reply's with baited breath

I have read this 3 times, plus all the subsequent thread replies.... And I am still very confused.

What were you doing at the property? why did you spend time time trying to diagnose a fault? And why did you do this before trying to contact the customer?

Puzzled!

 

[PEG]

I would like to thank this thread,after a lifetime of refraining from both drink and drugs,to suddenly make Spice,worth trying...

 

[westward10]

What "Old Spice"

 

[buzzlightyear]

@ buzzlightyear
Does the "Lightening" Icon (that appears to LH-side of main a-b display )
on a Fluke 1653b indicate its within it operationg range
of 100 V – 265 V ac, 50/60 Hz ?

 

[Andy]

I have read this 3 times, plus all the subsequent thread replies.... And I am still very confused.

What were you doing at the property? why did you spend time time trying to diagnose a fault? And why did you do this before trying to contact the customer?

Puzzled!

Hi
I have known the owner / customer for many years.
My son also lives on site
I was there to do a few jobs for him,
PAT Test 3 Rental holiday cabins / rectify 3 lighting timers that had never worked properly (there working fine now) / install a lighting circuit in a utility shed that had never been done (no need for head torches any more) / repair outside lighting that had been hit by cars (job done)/ install immersion heater circuits as they were just running off a plug on a std ring main (all nice and tidy now no more trailing leads), etc etc the list goes on.
Until recently he had been using another electrician but they had fallen out for some reason and he asked me to go and sort all the problems out.
Having done all the work I'm not surprised they fell out!!
I would never just investigate without contacting the customer but he lives on site and I told him, as I said earlier I had to vacate the cabin as people were due in so I didn't have a chance to check out the CU.
Don't really see what this all has to do with my initial post but there you go I hope I've satisfied your curiosity

 

[buzzlightyear]

but was their any volt drop, or did you read the fluke wrong.

 

[Pete999]

A belated birthday greeting , Pete999

Cheers static

Thanks for the info much appreciated.
You've confirmed my thoughts, so I'll be checking/testing everything on the circuit
The one place I couldn't get to for long was CU as we had to vacate the cabin as it had been booked out
As I keep saying the instrument I used for my testing wasn't the pat tester.
It was/is a Fluke Multimeter 1653b (does pretty much everything)
As I said to begin with its a sm Ring final circuit with 1 spur off.
I think that people have assumed I'm not qualified

Your profile doesn't list any qualifications, are you a full scope DI whatever that means?

 

[Pete999]

View attachment 37351for pete ,sent you a funky chicken card !

View attachment 37350

Ta

 

[Andy]

Too many questions Dave, he wants answers but not the questions that lead to the answers.

wjat fault are you expecting to find in the CU connections? Or is it a random guess?

Did you measure the 60V open circuit or with any load connected?
Did you carry out an earth fault loop impedance test of the circuit?
Did you observe any appliances working correctly whilst plugged in to an affected socket or do you only have the customers word for it?

I'm expecting to find a connection fault in the CU
I measured an open circuit no loading involved
Didn't have time for a earth fault loop impedance test
Yes I observed a sm Tv & Wifi hub working

Apparently its been working ok since the cabin was built, but when i looked at the installation certificate the circuit wasn't on it and it was defiantly installed when the cabin was built and not an add on after.

 

[Andy]

but was their any volt drop, or did you read the fluke wrong.

Volt drop