UPS NEUTRAL

[Abdelrazek]

In a three phase UPS, how to get a neutral for the single phase loads.
also why the DC source is divided by two DC/2 in the battery bank and what is its function.
Thanks

 

[tom baker]

Is it a wye output? What does the manual say for wiring?
Can't answer on the DC source question.

 

[Abdelrazek]

Dear Mr. Tom.
Thank you for your reply.
I'm talking about 3 phase UPS, the inverter output is 3 phase directly connected to the inverter.
there is no output transformer.

Is it a wye output? What does the manual say for wiring?
Can't answer on the DC source question.

 

[ron]

In the larger UPS's, there is often 3Ph 3wire output only. You need a transformer to get a neutral.

The DC source arrangement is manuf specific, and Schneider for example, just arranges their DC bus that way to work with their rectifiers and inverters internally.

 

[JoeStillman]

I've seen UPS battery banks with a mid-string disconnect to limit voltages when disconnected.