Input load when charging from flat

[Anonymous user]

Hi,

We have just purchased 2 Smart-UPS RT 6000VA units and the devices that will be connected to each unit only draw around 10A maximum. I know that the manual specifys a 32A supply but that is for full load and we are nowhere near using the full load.

We already have 2 x 16A receptacles available in the data center and I want to know whether it will be OK to hardwire the UPS's into these? Running 2 new 32A supplies will mean a whole new sub distribution as we are at capacity and is going to cost a packet!

We won't ever exceed the 16A on the outputs but my concern is that we might overload the supply when first connecting the new UPS's as they will be charging the batteries from flat and powering the devices which draw 10A.

Could anyone tell me the what the Amps drawn on the input would be in this situation?

Thanks,

Graham

[BillP]

i'll double check for you Monday when I have access to the specs but I am 95% sure on this model that the max charging amperage is not over 2 Amps. i can also get the charging wattage for you.

so yeah, the biggest issue with this set up is keeping an eye on your actual capacity so you dont trip the upstream breaker at your panel since the UPS wont trip because it can handle more than 16 amps.

i was wondering, is this a 20 amp circuit but you are calling it 16 amps because of National Electrical Code 80% rule, that a circuit cannot exceed 80% of the breaker rating?

[TheNotoriousKMP_apc]

I would imagine it would have to be more than 2A given the double online topology of the UPS.

The input power specifications should probably not affect the output side all too much, given that the output breakers would trip before the input side does.

But the fact that the input power, while in normal mode, directly charges the batteries which are directly outputting to the load, should require more than a 2A maximum input current.

[BillP · Accepted solution]

i double checked the specs.

SURT6000XLT (208/240v) OR the SURT6000XLI (230v) both have a charging current of ~2 amps and the charger size is 400 watts.

[Anonymous user]

Thanks, that's exactly what I was looking for.