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

 

[Andy]

Cheers static

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

I'm a Domestic Installer, at 57 I have no yearning to work on commercial/3 phase

 

[Andy]

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.

Yep open circuit

 

[Andy]

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.

Yep open circuit

 

[Andy]

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

Not really after answers, just the thoughts of those who understand better for me to bear in mind when i go back

 

[DPG]

Do a plan of the wiring - make sure you know where every cable goes.
Zs tests
R1/R2 tests

The results of the above will point you in the right direction.

 

[Andy]

Do a plan of the wiring - make sure you know where every cable goes.
Zs tests
R1/R2 tests

The results of the above will point you in the right direction.

will do
thanks

 

[westward10]

I would say this is a simple fault if appliances are operating, I am going for earth continuity.

 

[Des 56]

How many threads I have read where voltage readings(regrettably sometimes with the wrong instrument)have been noted on an installation and all sorts of sometimes wild claims are made by the operator
Concentrating the mind on voltage readings and assessing the safety of an installation on those readings is a sure fire way of coming to wrong conclusions

There are better and tried and tested means of making the assessment of the safety of an installation
Those who are unsure of how or what to test,they are the usual culprits for not being aware that wrong assumptions can be made
I suggest refraining from condemning work based solely on voltage readings,that is until the proper safety tests confirm there actually is a problem

 

[static zap]

Already have ,(origin of operating volts limits)
No worries , this piece of string has too many unknowns !

 

[taylorosso]

take end to end readings at the db for that circuit. That will atleast highlight if the ring is open somewhere...