208V to 208/120 transformer

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You get 208 volts coming in via an L6-XXP plug. Output is an isolated
120/208 volt split phase. So how would this be done?

http://www.apcc.com/products/resource/include/techspec_index.cfm?base_sku=SURT003

One possible idea is:

|<------- 208V input ------->|
| |
* *
\/\/\/\/\/\/\/\/\/\/\/\/\/\/
===================================
/\ /\/\/\/\/\/\/\ /\/\/\/\/\/\/\ /\
* * * * *
| | | | |
A B C D E

A-C = 120V
C-E = 120V
B-D = 208V
A-E = 240V

C might even be bonded to ground.

Another possibility is that it is not really 120/208, but some compromise
voltage like 112/224 output (so they don't have so many transformer taps).

How would I be able to determine exactly what they are doing? They do not
seem to provide schematics for anything.

 

[krw]

I downloaded the manual, but you're right, it doesn't tell me great deal.
It does say that there's an input selector switch for 208 or 240 V, so there
must be an extra primary tap, but that's not really relevant to your
question.

Actually, it may well be relevant. 208V output may only be available
with 208V input. IOW, only a center tap on the secondary (no
connections B&D).

<snip>