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Isolation transformer - getting full, rated kva

I am having my electrician install a Topaz 5kva isolation transformer (TP-91905-68) that will power 4 dedicated circuits in a seperate, dedicated sub panel. The electrician has 220v coming in off the main panel into the Topaz and then 120v going out of the Topaz to the sub panel. I thought I had read in one of the posts here that in this type of installation, if not done correctly, you cold actually only be getting 1/2 of the rated output of the isolation transformer (so, 2.5kva versus 5kva).

If anyone has knowledge of this particilar isolation transformer in this type of configuration and can shed some light on the situation (if in fac there is an issue) I would be very grateful.
dangelod

Showing 2 responses by ngjockey

ngjockey
1,042 posts
 
It's 220/440-120/240. That means that it will have 4 output conductors (not including ground) and they would be wired in parallel for 120V and series for 240V. It's possible to use only half but it's hard to imagine an electrician doing that.

Don't remember if Topaz uses the H1-H4/X1-X4 convention. If it's new, there should be some sort of schematic inside the "end" enclosures.
ngjockey
1,042 posts
 
Assumed this was for Europe or somewhere international.

Might be some confusion with derating for balanced AC, which isn't the question here and not trying to confuse the OP.
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