Volt Stick Strangeness

compaq · Aug 12, 2008

We got called to a house today for a minor works job.
TNC-S system, all electric night storage heating and immersion heaters.
While we were there we noticed our Volt Stick was lighting up on the pipework and cylinder in the airing cupboard.
The pipework was not live as we had been lent against it while working next to it.
The main bonding was in place to the water main, we tested continuity between the water main and the cylinder and pipework, it was fine.
The pipework was cross bonded fine.
We tested continuity between the main earthing terminal and the pipework, it was fine.
We then got interested and found that the Volt Stick only lit up on pipework in the immediate vicinity of the airing cupboard.
We then tripped off the mcb to each circuit in turn and found that the Volt Stick did not light up on the pipework when the lighting circuit was switched off.
We then pulled the lighting circuit out of the consumer unit and carried out insulation test on it, it was fine.
Carried out Ze, Zs tests, all fine.

Has anyone else experienced anything like this before?

sparkyork · Aug 12, 2008

mmm strange one! them volt sticks can be tempremental at the best of times but only getting the glow when the lighting circuit is energized! i was always lead to beleive the volt stick works on emf's and static when you rub it on ya trouser leg? could the pipework somehow be running in close proximity to a lighting cable and picking up some sort of emf this way??

rich

compaq · Aug 13, 2008

Thanks for your reply.
After talking about it today, we reckon that one of the pipes is resting heavily on one of of the lighting cables up in the roof.
Another sparky said that he had a similar volt stick light up on the fibreglass insulation in the roof, this was found to be caused by some flooring board squashing a lighting cable against a joist, when he removed the board, the volt stick stopped lighting up on the fibreglass.
Stange business isnt it.