ECN Forum Forums General Topics of the Trade General Discussion Area Bad Grounding

Electric Eagle
Member posted 03-12-2005 07:07 PM
--------------------------------------------------------------------------------
I think you should claim that it is defective siding and have the manufacturer do an inspection and a claim. They may rside the house at no cost to you. Is the side of the house affected the south or west side? If so, the sun and the foil may be causing this, not the electricity. I wouldn't even mention the electricity theory to the siding maker.

Bad ground? Well, stranger things have happened. If there were evidence for it, like say voltage, I might think it possible. As I have "heard" of something simular happening to AL siding once. (Removed paint from siding in a wierd pattern from the service to the water pipe, one of those things for Myth-busters.) And on this forum once, there was that neon transformer that had HV arcs jumping along the metalic threads of some wallpaper. (Something not possible with a 120/240 service)

I'm gonna side with Hal on the installer nailing too tight. (Allowing for thermal expansion and movement.) Who knows.... It might correct itself by say, next July.

Thanks for all the input, all the evidance is pointing to a manufactures defect. The contractor does not want to pay to replace the siding and an easy way out is to blame it on an electrical problem, so he is not responsibal. I am in Western Mass and the sun hits that side of the house around 2pm to sun set. This would be the southeast side of the house. The sun does not hit that side of the house directly it hits it at an angle for half of the day. I will post what the final out come of this problem is, I think I am in for a fight with the contractor and might have to take things to court. Thanks to all that resonded.

SnakeBite,
Are there any other houses nearby that would possibly have a mirror or some shiny object inside their house that would be reflecting the suns rays back thru a window that would cause a magnifying glass effect? Or perhaps some water in a pool or bird bath reflecting the sun? Because the shutter is also warping, but not the siding behind the shutter, it would appear to me that an external heat like magnified sun rays are causing the vinyl to warp.

How about this:

A nail hits a hot wire at some point.
The head of the nail is in contact with the foil on the insulation board causing it to become energized.
The foil, (or even another nail) is in contact with ground somewhere diagonally from the first nail, causing a high resistance fault path which generates enough heat to warp the siding, but not enough current to trip the CB.
Try removing the siding at either end of where the warping begins check for voltage, or try unplugging all the loads and seeing if a current is still flowing somewhere.

There is nothing I can see that could cause a reflectig effect or any thing near by that could amplify the sun. The warping or meltig effect is effecting the shutter but not under it. The siding guys used standard roffing nails 1 inch, the sutters are held in with 3 inch self tapping screws. I do not think the nails could go throw the wood and the old asfalt siding, to hit a line. The screws that hold the sutters up could, but upon examing the house I could not find any lines behind the shutters. What if the shutter screws did hit a line(all lines are in armor cabel)wouldnt the vinal siding under the shutter melt to. This house has the old screw in fuses nob and tude wouldnt they blow? They are very sensitive. All opinions will help. Thank you.

Guys,
Is this Vinyl metallic at all?
As in a vinyl coating on steel?.
If it is non-metallic, I would tell the AHJ to go jump, because it sounds to me like the length of the sheets have been mis-judged.
The variations are because of temperature, not because of some idiot idea about "Ground Currents".

This is 100% vinal siding no metal, there is a foil type insulation, like tin foil but much thiner. The insulation is white on one side foil the other, foil side out.

Foil is metal. If it's conducting electricity, it's resisting some of it and converting it to heat. Being as this is heat insulating material, it wouldn't take much to produce a heat rise (one of the reasons not to stuff insulation around K&T).

I'd think if a nail clipped a wire and energized the foil, this would at least be detectable.

The thing I haven't seen mentioned is inductive heating. If any wiring in the affected wall is not returning current along the same path, it can induce current in the foil lining. Then depending on different parts of the foil are attached to each other, there might be a circular path in this foil.

If there is a ground fault going to a point of ground somewhere other than the EGC, that would form a wide path that can cause inductive heating. If the ground bond is bad, it could be sufficient impedance to prevent overcurrent protection.

If I were checking this, I'd clamp around the ground wire and each of the circuit cables to check for a low current ground fault loop (possibly coming back in through that bad ground bond to return to the source). If that shows nothing, I'd shut off the circuits to all the wiring in the affected walls and see if the melting progresses further.

Anyone have IR scope to look at this with, especially at night?

Just had another thought regarding this thread. Any chance this house has active K&T in it?