I am on a service call for a brand new mobile home with a panel inside a sub outside the serves the inside panel and the ac unit fed from a main service with 5 other meters. Inside the house the flooring is that linoleum fake wood stuff and anytime you walk on it and touch anything metal it shocks you appears to be static electricity but when it’s something that is bonded, it really shocks you. I checked the main it has a main bonding jumper through what appears to be a ufer. The neutral and the ground are separate from the main like they should be but we are getting .25 to .1 v intermittent between neutral and ground in different places throughout the mobile home. Any ideas?
Static electricity
- Thread starter Jnewell
- Start date
- Status
Beaches EE
Senior Member
- Location
- NE Florida
- Occupation
- Electrical Engineer / Facilities Manager
The 0.25 to 1 volt does not seem to be anything of concern. Perhaps the static discharge to a solidly-grounded metal object is also normal. In a darkened room is there a static-discharge spark? What's the humidity level in the home?
Yes the discharge spark is clear. When I test from myself to ground I’m getting between 2-3 v. I just ran a jumper straight to the panel because my tester is reading a intermittent connection between on the neutral side. Which dropped the voltage between neutral and ground to 0 and the voltage between me and the ground to 1.5-2v. I am in Las Vegas where it’s fairly dry but this is an air conditioned house set to 73.
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
Very simply put: if you have a static charge built it will spark as it tries to equalize between you and the surface you touch. A grounded object by definition is connected to earth which is a much bigger surface than a door knob, so the discharge occurs 'faster and stronger'.
ptonsparky
Tom
- Occupation
- EC - retired
You generate the charge by walking on the floor, or the nylons rubbing on the cashmere.
At an electrostatic work station (electronics bench) there is a 1meg resistor in the ground strap between your wrist and the ground bar on the bench. That high of a resistance is low enough to dissipate static electricity. Well grounded things probably just get you bit harder since it can discharge quicker. There are antistatic floor waxes that could be tried. Try throwing a grounded metal screen on the floor to verify that's the problem (that should suck the charge out of your feet and shoes instead of letting it build up). They could add decorative copper or aluminum strips on the floor in some pattern to suck out static, but I don't think they will be durable. Clothes and humidity also have an effect, but it sounds like its hitting everyone so clothes isn't it. Humidity can be increased (I think 40% to 50% is ideal).
Try either lightly spraying on or damp mopping the floor with a diluted mixture of fabric softener and water.
Tell the home owner she/he may have to experiment with the ratio of fabric softener to water to find what mix works the best. For starters try one part softener to 5 parts water.
Tell the home owner she/he may have to experiment with the ratio of fabric softener to water to find what mix works the best. For starters try one part softener to 5 parts water.
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