We often see ups rated power: 3KVA or 5KVA and so on. What is their actual output power?

On the efficiency: all electrical equipment rated capacity or power or current refers to the rated output capacity, efficiency is a reaction to the loss of the equipment itself, because the UPS is a power conversion device, not a load, theoretically, I hope that his own electricity are not consumed. Rated capacity of the same two manufacturers of UPS, although the efficiency may be different, but with the load capacity is the same, just efficient UPS from the input side of the smaller energy, if the very rich, do not care about this point of the electricity bill, can be ignored.

Capacity: UPS manufacturers calibrated capacity parameters are rated capacity and power factor. For example, a rated capacity of 5kVA UPS, power factor of 0.8, then its rated active output capacity of 4kW, rated reactive output capacity of 3kvar. UPS can be interpreted as a power supply equipment that can output active power and reactive power, the active and reactive power of the load with the load must be in the rated range, if there is a load rated power of 4kW, power factor is 0.7, then regarded as in the rated range. Is 0.7, the apparent power is 5.7kVA, reactive power is 4.08,kvar, then the above example of 5kVA UPS is not up, for the power factor is 0.7 of the load must be used to verify the reactive power, UPS rated reactive output is 3kvar, according to the 0.7 power factor converted to active power of 2.94kW, apparent power of 4.2kVA. In summary a power factor of 0.8 5kVA UPS, if the load power factor is 0.7, can only take 2.94kW or 4.2kVA.

UPS is a power supply equipment, not the load, the power factor of the power supply discussion is meaningless, because the power factor of the power supply and the load is the same, for example, transformer rated parameters do not have a power factor, 5kVA UPS is a power electronic device equipment, 5kVA UPS can not be like a transformer to provide full capacity of active or reactive power, UPS can not provide full capacity of active or reactive power, UPS can not be like a transformer to provide full capacity of active or reactive power, UPS can not be like a transformer to provide full capacity of active or reactive power, UPS can not be like a transformer to provide full capacity of active or reactive power, UPS can not be like a transformer to provide full capacity of active or reactive power. UPS active or reactive power, UPS active load capacity and reactive load capacity is separate, active and reactive power distribution is to use the power factor of this parameter to specify. The actual work of the UPS power factor is also consistent with the load, and not always maintain its rated power factor operation. So the power factor of the UPS power supply and load power factor is not the same concept. UPS manufacturers in the design and manufacture of arbitrary power factor: 0.7, 0.8, 0.9, etc., the design principle is to try to match the load, so that active and reactive power output can be maximized at the same time, there will be no waste of capacity. The power factor of the load to ensure that the normal operation of the case, is generally hoped that the higher the better, the power factor of the UPS is not the higher the better, all manufacturers have the ability to design the UPS power factor of 0.9, and the actual application of why there will be a power factor of 0.7, 0.8 of the UPS? This is to match different loads.