How to calculate the ratings of UPS against different power units with respect to battery back ups?
Not sure what you are asking. I think you are confused between KVA and KVA-hours. KVA and KW are units of power. This is the rate at which the unit delivers energy. Multiply by time to get energy. KVA-hr and KW-hr are units of energy. divide this by the time to get power. So a 1000KVA unit will deliver 1000KVA as long as the battery lasts. Changing the battery size doesn’t change the 1000KVA. A unit that can deliver 1000KVA for one hour can supply a total of 1000KVA-hr of energy. If it can supply it for 2 hours, it can deliver 2000KVA-hr of energy. Watts and VA (or KWatts and KVA) are both units of power, one is for real resistive load and the other is for reactive load. To calculate the UPS size, add up all of the loads in watts*. Convert to kwatts by dividing by 1000. Add some margin. That number in kW is the amount of power the unit should be able to deliver. I’d ignore the KVA rating, it doesn’t mean much. Now look at the time. How long do you expect it to deliver that amount of po
