retcec
Member
- Location
- Washington, D.C.
A recent issue came up with a double insulated tool during a safety inspection. An inspector tested an energized double insulated screw gun and found voltage to ground. The inspector placed a voltmeter from the tools metal surface to a nearby receptacle ground opening and got the reading of ~5V.
Seems like a few issues with this test that could have caused the voltage. First, the double insulated tool naturally has no connection to ground, and any system ground will be a different potentials, resulting in the voltage that could have been on the ground from any other circuits connected. I don't know if a test of the tools plug (prongs) to this same metal surface was done, which could have indicated a real problem.
Has anyone seen anything like this before? What could have caused the voltage?
Seems like a few issues with this test that could have caused the voltage. First, the double insulated tool naturally has no connection to ground, and any system ground will be a different potentials, resulting in the voltage that could have been on the ground from any other circuits connected. I don't know if a test of the tools plug (prongs) to this same metal surface was done, which could have indicated a real problem.
Has anyone seen anything like this before? What could have caused the voltage?