UPS question.......

[Fulthrotl]

ok, here's what it is:

100 amp 120/208 three phase 4 wire Y panel,
pulling about 50 amps per leg max.

needs to go on a UPS. building is 3 phase 208 4 wire Y.
now, a backup generator comes into play on this, if the
power goes down. herein lies the rub. generator is a
30 kw 120-240 3 wire single phase diesel genset.

manual transfer switch to be used to switch from poco
to genset.

this is typical of what is available.....

http://www.apc.com/products/resourc...x.cfm?base_sku=SUVTP30KF4B4S&total_watts=4000

now, the rub... does anyone know of a 3 phase UPS
that can charge off a single phase source?

i've hooked one like that up in the past, but i'm unable
to find anyone who currently makes one.... does anyone
know of such a beast?

 

[Pullnwire]

Hmmm. In theory, it should not matter in a true AC-DC-AC system. Would just have higher amamperage per phase. I have seen this before, but in smaller rack mount units. It was 208 1phase in and 120/208 3phase out to a couple rack mount PDU. I believe it was an Emerson unit?

 

[ceb58]

Try Eaton Power Ware.

 

[brian john]

In some installations where the UPS is a smaller unit (10-20 KW) and the customer wants a much larger battery than is standard for this UPS, typically the internal UPS rectifier cannot charge the battery is a reasonable amount of time, so a larger single phase external battery charger is utilized. I am sure you could do the same here. But to keep the battery at a level where it could sustain the load for long periods of time I would think you would need a fairly large charger maybe 100-150 amps. Finding a single phase 150 amp charger at the higher battery voltage of 200+ VDC, would be a problem.

 

[Fulthrotl]

In some installations where the UPS is a smaller unit (10-20 KW) and the customer wants a much larger battery than is standard for this UPS, typically the internal UPS rectifier cannot charge the battery is a reasonable amount of time, so a larger single phase external battery charger is utilized. I am sure you could do the same here. But to keep the battery at a level where it could sustain the load for long periods of time I would think you would need a fairly large charger maybe 100-150 amps. Finding a single phase 150 amp charger at the higher battery voltage of 200+ VDC, would be a problem.

yep... it would seem that such a solution would have to be made out of
unobtanium, and there is a shortage of that.

thanks for taking the time to post on this one everyone....

 

[brian john]

I was guessing and not sure what your intent was.

 

[Fulthrotl]

I was guessing and not sure what your intent was.

my intent was to be able to use a manual transfer switch to feed this off a trailer
mounted single phase 30kw diesel genset, while providing 3 phase power to feed
a little panel... it's a 3 phase building, but the constraint is the genset.

new plan is to mount a single phase panel off a 16KW refurbished APC single
phase UPS, and switch the loads over to the new panel, leaving the original
panel unused, as a spare.

finally got a load check on the panel in question today, and peak load is 6KW,
average for all 3 phases is 4.5 KW. the UPS they are planning on using can
support that load for about 4 hours.

thanks again for your input.