Its been a shocking experience!

[westie101]

What could give that effect where the volts are there with the cutout fuse removed is incorrect polarity.

Does the problem still exist if
1/ the circuits are switched off via the individual MCB's in the consumer unit

2/ If the consumer unit main switch is off

 

[oldhousescot]

1 - Yes

and

2 - Yes

 

[bernardgreen]

Hi

The plumber described the shock as not always being there he would maybe be able to grip the pipeowork for up to 20 sec before he would feel the shock.

That is not static electricity. He is gripping the pipe that shocks with one hand, where is the other hand or any part of his body near touching other metal work or damp surface or damp wall.


It might be that the local network neutral is floating ( a network fault ) and if the CPC ( earth wire ) to the house is derived from that ( as in PME ) then anything earthed ( or equipotentially bonded ) in the house is not at true ground potential. The voltage on the floating neutral would vary as other houses switched things on and off.

Its a grant vortex oil boiler. Oil supply line in copper.

Is it your individual tank or a shared tank ? Could there be a metallic connection to another house via the oil pipe work. Any trace heating on the oil pipe work. ? Though I would think that the metal oil pipe would be
connected to other pipes inside the boiler via the metal work of the boiler framework.

 

[oldhousescot]

not touching other metalwork in general just differing parts of the boiler.

oil tank is not shared. had been thinking of local fault, is there anyway to test for this to confirm?

 

[westie101]

I would strongly suggest that you contact your DNO emergency line

 

[oldhousescot]

Hi all,
Many thanks for all your help in aiding with the solution.

To give you all a update I contacted the local supplier and explained that people were getting shocks, they claimed that they needed various readings from my spark.

Spark materialised did tests and again found no issues, however out of curiousity he put his Megger from actual ground to pipework and recorded 50 volts.

Again contacted Scottish Hydro, explained issues and explained electrocution of plumbers, etc and within 2 hrs they had supply isolated to 13 meters in total. Eventually diagnosed fault with joint box underground, supply rejointed and problem disappeared!!

thanks again to everyone it is truly appreciated!!

 

[Taylortwocities]

within 2 hrs they had supply isolated to 13 meters in total.

Not sure I understand what you mean by that.

But pleased that all is resolved

 

[bernardgreen]

however out of curiousity he put his Megger from actual ground to pipework and recorded 50 volts.

Isn't it amazing how that sort of result will trigger a rapid response from the DNO emergency crews.

Yet (as in another thread) the non urgent person sent by the DNO to investigate voltage variations doesn't check the neutral to true ground voltage when a broken neutral is often the cause of voltage fluctuations.