building remaining energized with power cut off

[JeffD]

I was watching Mike Holt's dvd on bonding and grounding. I was watching the portion with the firemen addressing open neutrals. They were saying that even with all of the power cut to the building, the meter removed, parts of the building were still energized. I couldn't follow exactly why this was happening. I'm not sure if it wasn't addressed or if I was interupted when they addressed it. How exactly does this happen?

 

[petersonra]

UPS?

emergency generator?

backup power feed?

 

[bphgravity]

Probably stray currents coming in through the grounding electrode system.

 

[JeffD]

That might be it the voltages were small and the showed the water meter being disconnected and sparks arcing between the nut and pipe when it was being removed.

 

[bill@nkapc]

Power capactors feeding back to utility co.

 

[wireman3736]

customer stealing power off the top of the meter lugs.

 

[monkey]

Jeff if that's the same video I saw it was a duplex residence and one side (unit 2) had an open neutral at the main. As a result all of the neutral current from unit 2 was finding it's way back through the plumbing to unit 1. The shower in unit 1 was built with metal lath which was touching the pipes, this lath was energized and glowing along with the nails that were touching it. So even with the meter pulled at unit 1, things remained energized with neutral current until the meter was pulled at unit 2.