Need help regarding ISOLATION TRANSFORMER.

[jaikumar]

I wired up a isolation transformer like this

1) I have 2 primary 220, 50HZ. Secondary 0-12 volts

I connected the secondary's togother and one primary goes to the mains.

on the other primary I read the voltage with respect to ground i get 55 Volts, should i get zero, because the ground point should be isolated?

Thanks and Regards,
Jai

[DTiziano]

Hi

But do you read the voltage between one leg and ground ?
If yes then what you get depends of the parassitic capacity between the coils.
To get zero volt you need a transformer with a (grounded) shield between coils.

Regards

[pickit2]

Bet your Neutral of your mains is at or near ground at sub station. and this is what your reading.