> So wire size depends on A, and since the V are known (115V), it makes > sense that > the VA _of the load_ be used in calculating the conductor size . > > <><><><><><> > > Not if you know the PF. For example, I have a 20 KVA UPS that has an > aribitrary PF rating of roughly 0.8; so, in reality, it is a roughly a > 15 kW UPS.
You're right Terry: the power factor is defined as the ratio of power to Irms*Vrms > Now, the electrical dudes design the load cables for 20 KVA > or 167 A when it is absolutely impossible for the device to supply more > than 125 A (at 120 V). Insane. I don't understand why it is absolutely impossible, is the load's power factor unity i.e. is it purely resistive? If the load's power factor is equal to 0.8 which is typical of computer power supplies, the dudes are right I am afraid. Michel
