gas meters showing live on a voltstick

[Deleted User]

My workmate has to replace the batteries in gas meters and for this reason he has been given a Voltstick to detect any gas meters with electric current running through them.Before he replaces the battery he tests the meter and has found 4 live meters out of about a thousands meters over the last couple of years.
Could anyone tell me how a gas meter could end up with live current passing through it, and would there be enough current to kill anyone touching it. His Voltstick can detect from 50 volts ac to 600volts ac.
Are householders in danger from this sort of thing as 4 out of a 1000 seems very dangerous.
Its certainly got me a bit worried reading them all day but then I dont have to touch the meters

Terrylw1

Well, I'm definately not an engineer but I'm assuming it can't be a residual current left over by the time he gets there!

The regs were updated to keep a certain distance between gas & elec meters. Is it possible the elec meter was closer and the current was passed to the gas meter somehow? I'm just wondering if its a pre reg update set up...given all the scenarios with elec meters that are no longer compliant to current regs (my favourite always being the meter under the since, doh!...:rotfl:)

jalexa

sacsquacco wrote: »

Could anyone tell me how a gas meter could end up with live current passing through it, and would there be enough current to kill anyone touching it.

Almost certainly as a result of defective or missing main equipotential bonding. Induced voltage rather than current flowing.

It's a safe procedure not a voltstick which is required. And a warning letter to the householder about the bonding.

C_Mababejive

Voltsticks are held up by Employers as some kind of life saving tool and a panacea for all electrical defects. Ask any electrical engineer and they will tell you they are more or less Lucky Bag toys.

They do not actually detect electrical current.

They detect electromagnetic fields.

I also have one.

To date i have found that my big Toe is live,a plant on my bedroom window sill is live,the carpet is live,the ceiling is live ...oh and when i touched an incoming mains cable just before the distribution fuse..err...it wasnt live.

Piece of old crap.

The trouble is of course that some misguided employers will discipline you and maybe even sack you if you dont have it/use it.

[Deleted User]

Thanks, have just gone and bought one of these toys, will have to try my big toe with it, thats why I asked the question as I doubted that my work mate was finding all these lethal live gas meters, as I am sure I would have been to a couple of meter readers funerals by now

C_Mababejive

sacsquacco wrote: »

Thanks, have just gone and bought one of these toys, will have to try my big toe with it, thats why I asked the question as I doubted that my work mate was finding all these lethal live gas meters, as I am sure I would have been to a couple of meter readers funerals by now

Most of the false lives are caused by induction i.e a live mains cable or apparatus is sufficiently close to a pipe for example to induce an electromagnetic field of sufficient strength so as to light the toy.

Oh i forgot to mention...the pull up antenna of my portable radio is also live.

lemontart

C_Mababejive wrote: »

Most of the false lives are caused by induction i.e a live mains cable or apparatus is sufficiently close to a pipe for example to induce an electromagnetic field of sufficient strength so as to light the toy.

Oh i forgot to mention...the pull up antenna of my portable radio is also live.

oh dear that is simply shocking

chanz4

put one on an apple macbook pro case, same result

hjk

Whist the volt stick may indeed be a red herring and may be giving spurious readings, there is a potential problem with certain types of electrical supplies, gas meters, and a “broken return fault”. This is not a particularly common fault.

Many electrical supplies have live neutral and earth cables both inside and outside your house. (TN-S)

Some supplies, (called “PME” or TNC-S) have a combined “neutral/earth conductor outside, and live, neutral and earth cables inside.

In both cases normal practice is to bond your gas installation’s metal to the electrical earth wire.

If the combined neutral/earth conductor on a PME/TNC-S supply goes open circuit outside, all the return current flows out though water pipes, gas pipes etc, and you don’t know about it.

Mains current then does flow through the gas meter.
Those removing a meter would find 230V between the external and internal gas piping - potentially fatal, but only once the meter is removed.

In these circumstances, putting a clamp current meter on gas or water pipes before removing anything would show significant current flow and warn of the problem.

Finally it's worth reiterating that volts sticks do not show that current is flowing, just that voltage is present, and they can give spurious indication due to "pick up".

ollski

I always use it, if it lights up I check it with the meter. It's very rare but I have personally been to a couple of jobs over the years where everything has been mains live....both from faulty washing machines actually!

C_Mababejive

hjk wrote: »

In these circumstances, putting a clamp current meter on gas or water pipes before removing anything would show significant current flow and warn of the problem.

Finally it's worth reiterating that volts sticks do not show that current is flowing, just that voltage is present, and they can give spurious indication due to "pick up".

Exactly..we are in agreement. The only true way of detecting current flow in such circs is,as you say,to use a clamp meter. Employers like cheap solutions so they buy toys,tell people that this is the definitive test for safety and then discipline/sack them if they are found not using the toy.