ECN Forum Forums General Topics of the Trade General Discussion Area 50 Volts

Why is it when you have a switched outlet (the top is switched and the bottom is always hot), you turn off the switch that there is still 50 volts reading on the switch leg? When you ground the switch leg the voltage goes away? Electrical phenomenon?

That is just a problem with these new high impedance meters. Withno load on the line you will see antenna effect.

NEMA calls this 'phantom voltage' and it is real voltage with almost no current.

The wire that you are getting 50 volts on is picking this up simple by running next to other live wires.

You meter draws so little current it can measure this phantom voltage.

Try the same thing with an older analog meter.

Or use a set of Wiggys and a digital at the same time and you will see 0 volts on the digital.

A (near) full description of this can be found here .

M.