[GreenKeys] Model 15 chassis voltage?

[Trammell Hudson]

Is there supposed to be a voltage on the Model 15 chassis?  All three 
of the ones that I have tested trip GFCI outlets instantly if I ground 
the chassis to the green wire on the power cord.  Measurement with a 
multimeter shows 20-40 volts AC between the chassis and the neutral line 
on the input when the ground is left floating.  This occurs even with 
the switch in the off position.

-- 
Trammell