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TonyDuell · 27th Jan 2023, 6:35 pm

I feel that the 'There is no one right answer' that has been previously suggested in this thread certainly applies.

If you are using an isolating transformer on audio equipment and you don't inspect/check the wiring of the equipment before plugging it in, as I believe the BBC were doing, then it makes sense not to have the earth pin connected. There is a slim chance of an undetected fault that could have fatal results

If on the other hand you are using the isolating transformer on an electronics workbench for testing/repairing mains-connected electronic circuitry (AC/DC radios and TVs, switch mode power supplies, etc) then there are times when having that earth pin solidly earthed is a good idea. I feel that anyone who knows to use an isolating transformer in such cases also knows how to inspect and test the mains wiring and will do so before plugging anything in.

27th Jan 2023, 6:35 pm	#48
TonyDuell Dekatron Join Date: Jun 2015 Location: Biggin Hill, London, UK. Posts: 5,215	Re: Isolator Transformer Query I feel that the 'There is no one right answer' that has been previously suggested in this thread certainly applies. If you are using an isolating transformer on audio equipment and you don't inspect/check the wiring of the equipment before plugging it in, as I believe the BBC were doing, then it makes sense not to have the earth pin connected. There is a slim chance of an undetected fault that could have fatal results If on the other hand you are using the isolating transformer on an electronics workbench for testing/repairing mains-connected electronic circuitry (AC/DC radios and TVs, switch mode power supplies, etc) then there are times when having that earth pin solidly earthed is a good idea. I feel that anyone who knows to use an isolating transformer in such cases also knows how to inspect and test the mains wiring and will do so before plugging anything in.