On Thursday, 3 January 2019 11:22:40 UTC, Roger Hayter wrote:
Brian Gaff wrote:

Hi, In the past in a shed I used to work on equipment with a live chassis by
having it on the other side of an isolating transformer and earthing the non
live side, if you get my drift. After all this is just what replacing an
auto transformer would do to mains gear of that age.
However I used to fly by the seat of my pants in those days, and so what
I'd want to do with my new shed when its built is also to protect that
circuit with more than a 5 amp fuse.

Now I'm probably well outside of the law here on this one but two problems
come to mind. First what sort of breaker and also of course you would need
any gear connected to have a plug on it that could not, accidentally be put
into a standard socket as that would be disaster on many levels. are there
special plugs or sockets for this kind of use?

Brian

I used to do the same, but I haven't seen any live chassis equipment I
wanted to repair for about fifty years. And getting the series heater
replacement valves might prove expensive.

under an hour's pay each

Having said that, I can't think of any way an isolated supply with one
side connected to local earth could be protected in any way that doesn't
make it more hazardous to the operator rather than less.

RCD after the iso transformer.


NT