Is this an Isolation Transformer

[Aperna1985]

I'm really happy I finally have an isolation Transformer. Everybody has been saying to get one since I started messing with this stuff. Now here's my question when you're doing testing do you plug what you're working on into the isolation Transformer or do you plug your test equipment into the isolation Transformer?

[Electronic M]

Originally Posted by Aperna1985

I'm really happy I finally have an isolation Transformer. Everybody has been saying to get one since I started messing with this stuff. Now here's my question when you're doing testing do you plug what you're working on into the isolation Transformer or do you plug your test equipment into the isolation Transformer?

The short answer is YES.

More accurately you can plug EITHER your test equipment OR your radio/TV project in, BUT NOT BOTH at the same time.
I favor the radio/TV being isolated as test equipment makers (atleast in the SS era) usually didn't make their gear in a way it could prevent a shock Hazzard.
But really it's up to you.

I do recommend checking the isolation with ohm's mode on a DMM...On a normal 50s vintage isolation transformer I used to have it one day developed a spontaneous primary to secondary short....I got shocked a few times off of it before I rechecked it and discovered that it failed....

A GFCI wall outlet is also a good back up to have to catch failures like that.

[ppppenguin]

Usual to plug the radio etc under test into the isolating transformer.

The output of the transformer should float. Neither end grounded.

A GFCI (RCD on this side of The Pond) is of no use on the output side of an isolating transformer. Apart from the rare and special case of a failure of the transfomer itself it doesn't give any extra protection on the input side either.

If working on a hot chassis (live chassis in UK/Europe) set an isolating transformer is essential if you want to connect testgear to the set. Otherwise you can make sure the chassis is conencted to neutral and use a GFCI/RCD.

[dieseljeep]

Originally Posted by ppppenguin

Usual to plug the radio etc under test into the isolating transformer.

The output of the transformer should float. Neither end grounded.

A GFCI (RCD on this side of The Pond) is of no use on the output side of an isolating transformer. Apart from the rare and special case of a failure of the transfomer itself it doesn't give any extra protection on the input side either.

If working on a hot chassis (live chassis in UK/Europe) set an isolating transformer is essential if you want to connect testgear to the set. Otherwise you can make sure the chassis is conencted to neutral and use a GFCI/RCD.

I just worked on an Emerson portable radio that has a hot chassis yesterday!
I have several sizes of isolation transformers, but I seldom use them. Old habits die hard. Our low voltage, 120 volts is a lot less hazardless.
As an electrician, I believe in GFCI's and all the receptacles that I use when repairing are GFCI equipped, either receptacle or breaker.

[Electronic M]

Originally Posted by ppppenguin

Usual to plug the radio etc under test into the isolating transformer.

The output of the transformer should float. Neither end grounded.

A GFCI (RCD on this side of The Pond) is of no use on the output side of an isolating transformer. Apart from the rare and special case of a failure of the transfomer itself it doesn't give any extra protection on the input side either.

If working on a hot chassis (live chassis in UK/Europe) set an isolating transformer is essential if you want to connect testgear to the set. Otherwise you can make sure the chassis is conencted to neutral and use a GFCI/RCD.

Note I said a GFCI wall outlet to imply it's used on the input side of the isolation transformer. If the isolation transformer shorts primary to secondary and the chassis leaks current to ground, and if the transformer is plugged in to a GFCI wall outlet that is built in to the house the GFCI will trip and act as a fail safe if the transformer fails.