UPS Charging current

[m sleem]

Do we need to size the ups upstream breaker so that it's rated to the UPS FLC + Batteries charging current?

 

[qcroanoke]

Do we need to size the ups upstream breaker so that it's rated to the UPS FLC + Batteries charging current?

We do exactly what the installation manual says. From overcurrent/short circuit protection to wire size to input and output being in separate raceways.

 

[m sleem]

We do exactly what the installation manual says. From overcurrent/short circuit protection to wire size to input and output being in separate raceways.

I am preparing the tender documents, so it is pre installation.

 

[zbang]

It can't be that hard to call the mfg and ask, or even to check for representative units, then add a disclaimer that there are things you can't account for until you have specifics.

(I just looked up a 50kva/45kw MGE, the web page clearly says "Maximum Input Current 59.0A"; there are a lot more specs in the install manual- https://download.schneider-electric...Ref=SPD_MPOD-AFCEK2_EN&p_enDocType=User+guide).

 

[don_resqcapt19]

If the UPS always supplies power to the load, even with normal power on, then the power supply to the UPS will have to support both the actual load and the battery charging load. That way when normal power is restored, the supply circuit can supply both the actual load and the battery charging load.