13 volts on gas pipe

[techniphase]

a customer e mailed me the other day about finding the problem with his energized gas line.as soon as he told me his gas line had 13 volts on it, i imediately thought of the thermostat. besides gas appliances, a bonding mistake or thermostat in contact with the gas pipe, does anybody have any ideas? i would like to resolve this problem efficiently as possible.

 

[mcclary's electrical]

a customer e mailed me the other day about finding the problem with his energized gas line.as soon as he told me his gas line had 13 volts on it, i imediately thought of the thermostat. besides gas appliances, a bonding mistake or thermostat in contact with the gas pipe, does anybody have any ideas? i would like to resolve this problem efficiently as possible.

I would take the measurements myself before I did anything.

 

[kwired]

you need to know if this is AC or DC voltage, if the gas pipe is bonded to the electrical system, if the furnace control voltage is grounded (many newer ones are but most older ones were not), at what reference point was the voltage measured to, and if high or low impedance meter was used to measure.

 

[techniphase]

havnt physicaly been out at the job yet. It is a residence. Since the gas guy informed him, I would assume it is close to a valve somewhere or the meter ? I am going out at 10 am (pac time) this morning. The problem is, this customer is deaf so i really need to kinda find my own way here along with you guys posting killer ideas. I am always good with paying it forward.

 

[techniphase]

I use a standard digital combo meter from greenlee. Is that sufficient for this type of troubleshooting?

 

[augie47]

He may be seeing a "ghost" voltage depending on the meter he is using.
To me the biggest question is reading 13 volts to __ (what)..
If the gas line is properly bonded the voltage may on the other end of his meter. Step one, I would think, is to check the entire electrical system for proper bonding.

 

[templdl]

You are probably using a digital voltmeter with will measure a voltage across just about anything.

While measuring the voltage take a small 12v automotive light bulb and place it is parallel with the meter and with almost all certainty the light bulb will not light and the voltage will drop to zero.

 

[paul]

This is where wiggy's come in handy. I, too, am wondering what they were measuring to. Find that out and bond the gas line accordingly.