Steve,

DOES THE CRITICAL PANEL USE SINGLE PHASE LOADS?

If not, no problem.

If it does, is it a Wye or a center tapped delta?

If it is a Wye, then you need a delta-wye transformer for the maintenance switch.

If it is a center tapped delta, then you need a delta-wye transformer for the maintenance switch.

How does the output of the UPS’s output transformer get reference the earth? Since there are transformers on the input and output of the UPS’s, is there an issue with phase shifts? How does the maintenance switch get used? Is it thrown and the UPS’s are brute force paralleled with switchboard B?

Questions, questions, questions. [Linked Image]

LarryC

Edit for content.


[This message has been edited by LarryC (edited 08-10-2006).]