UPS charging current

[Anonymous user]

Can anyone help me with the charger wattage rating and/or charging current for the following models please?

SUA3000RMXLI and SURT8000XLI

I'm trying to calculate what size power supply is needed to support both these devices.

Thanks.

[BillP]

SUA3000RMXLI3U is likely the SKU you have which shows a charger wattage of 287W. SURT8000XLI's charger is 782W.

This UPS efficiency calculator (http://www.apc.com/tool/?tt=5) may help you as well if you drag the counters down to 0% load and it will show you the losses from the UPS itself in order to operate.

The user's guide also usually tells you what size (Amps) circuit the UPS needs to be on if that is what you were referring to.

[Anonymous user]

Great thanks for that.

Could you let me know how to calculate how much current would be drawn by both devices to charge the batteries with no load connected, assuming the batteries were at 0%?

You're right, I'm trying to figure out what size of circuit the UPS needs to be on, for the larger UPS the manual says 50A but that is at maximum load and we won't be running it anywhere near capacity.  I know how much current will be drawn by the equipment I wish to connect, I'm just trying to figure out the maximum current both UPS's will draw themselves, worst case scenario (completely dead batteries).

[BillP · Accepted solution]

OK, I understand. You'll just want to verify that local electrical code will allow that in your region, if you haven't already.

Those are the max values I've shared with you for the charger which would apply when the batteries are completely discharged. You'd probably want to add that to the "UPS total losses" at 0% load you can find from the UPS Efficiency Calculator I shared. 

The other thing to consider would be to allow for potential overloads, just in case.