SMALL (150VA or less) isolation transformer

[g-and-h_electric]

So here it is Sunday, and I am working on some antique hot chassis radios. Dig out a transformer marked ans an isolation transformer for safety reasons.

For some reason I decided to make sure it was as marked. I found the following: 1) no continuity between the windings ( a good start). 2) When plugged in I went and checked from the load side to ground, her is where I am now lost...... One side of load receptacle was about 65 V to ground and the other about 16.

I am confused ...... What gives, I was expecting nothing to ground fro either leg.

Any ideas? ( no i didnt get out the megger to test the insulation, just a fluke 83 for continuity)


howard

 

[LarryFine]

You're reading "phantom" voltages because your meter has a high input impedance.

Parallel a small 120v incandescent bulb with the meter and you'll read 0v to ground.

 

[jim dungar]

Coupling capacitance exists on all ungrounded systems. You should not expect valid voltages if you do not have a valid reference point.

 

[LarryFine]

You're reading "phantom" voltages because your meter has a high input impedance.

Parallel a small 120v incandescent bulb with the meter and you'll read 0v to ground.

To add, I use a solenoid tester (Knopp K60) for 99% of troubleshooting.