Isolation transformers, use of.

[Mark Hennessy]

An isolating transformer only feeds one piece of apparatus which must not be connected to any earth.

From an earlier post of mine:
That transformer is internally configured for 120v. - 0v. - 120v. bi-phase output with the 'E' / 0v. centre point connected to supply earth inside the commercially-built isolation transformer unit which has full Government electrical safety  approval.

Note: That 'earth through' arrangement has now been disconnected my me.

Al.

Which had full Government electrical safety approval until you modified it.

What "raylec" is referring to is the same as me - the use of an isolation transformer to allow safe connection of test equipment to a device under test.

Which is quite different to your use - which is creating a centre-taped supply that ensures that the supply could only be 120V w.r.t. mains earth (well, that was the case before you modified it).

Whether it's worth the effort of making a balanced supply is debatable, but if you have the transformer, and don't mind the space and magnetising current it consumes, then why not? You still need a separate isolation transformer for the use raylec and I refer to, so if you have one, and are aware of that, then no problem