Pex Tubing Providing a Path to Ground?

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mike n

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Any thoughts?
Today at a customer's home I was checking a 120v duplex for voltage.In doing so I noticed the hydronic baseboard carried the 120 volts from the outlet to ground,when I had my testers between the two points. The odd thing is that this baseboard is fed with pex tubing. My first thought was the heating system is fully charged,and the water in the tube is the conductor.I have the same system at home (so I tested ).one zone in my house is 47 volts and another zone is 70 volts. When I turn my circ on Both zones rise 20 or so volts.
So my question is my system the norm? Or perhaps the customer's loop is fully charged providing low resistance path (mine air bound).Or lastly maybe a screw through the baseboard housing and into a romex ? Has anyone ever seen this or am I the only nut!
Thanks
 
Are you using a digital meter? If so, their huge input impedance only requires microamps of current flow to measure voltage. I'd bet if you did it again with an old school analog meter, you would read much less voltage and perhaps none.

Alternatively, did someone decide that the baseboard could likely become energized (somehow) and ran a bonding wire to it?
 
Thanks for the reply.I used a fluke "wiggy".It is digital. I'll check for the bond.I was thinking of backing out the eight or so screws to isolate the metal housing,then I could check the element.Maybe someone out there has seen this. Analog will be a tough one to find.
Thanks
 
Pex-al-pex ( which is what you oughta have if you have a cast iron boiler ) has an aluminum oxygen barrier.

http://www.aqua-therm.com/pages/index.php?pID=23

I don't really see the electrical path, but I guess something might be possible. Having aluminum present makes a little more sense than plastic alone.

You sure it's not the high impedance meter?
 
I used a digital voltage tester fluke T5-600. Looks like I should find an old analog multi.
This tube btw is all plastic (orange)
Thanks.
 
Metal studs = ground. Boxes mounted to them, duct systems water piping appliances attached.

Otherwise I would go with the phantom voltage that has been covered numerous times in this forum.
 
mike n said:
I used a digital voltage tester fluke T5-600. Looks like I should find an old analog multi.
This tube btw is all plastic (orange)
Thanks.
Click to expand...

A solenoid type tester is the thing to have. Home Depot has Ideal solenoid voltage testers for 20 bucks for the basic and 35 for the Vol-Con which also has a continuity tester built in.

yhst-38616620066226_2051_253444112


Either one is worth it's weight in gold plastic.
 
mike n said:
Thanks for the reply.I used a fluke "wiggy".It is digital. I'll check for the bond.I was thinking of backing out the eight or so screws to isolate the metal housing,then I could check the element.Maybe someone out there has seen this. Analog will be a tough one to find.
Thanks
Click to expand...

load down your DMM with a small 120V light bulb across the input...the meter you have is too good for the application.
 
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