We have a three-phase online data center UPS.
Someone said recently that if the input amperage across the phases were 70-10-10 we'd pay for the kWh represented by 70 amps, but if the same load were spread out to 30-30-30, we'd pay for kWh corresponding to only 30 amps.
Really?? I can believe that balancing the load across phases puts less stress on the UPS. But does it also reduce the power bill so dramatically?
I'm not sure how your power is metered, but this is possible (it would be a question for your power company as to how your usage is metered - peak phase, averaged across all 3 legs, or total consumption (each phase metered & summed)).
Regardless of utility costs though, you should speak with an electrician and balance your load across all three phases for the other reason you mentioned - It's kinder to your UPS equipment.
Datacenter grade UPS systems are EXPENSIVE to service/repair, and the maintenance windows almost always require putting the UPS into bypass mode (which means no power protection). Re-balancing your load will reduce heat and other stresses on the UPS system and improve your overall operating efficiency.
Additionally I've found it's easier to plan new build-outs and added capacity if your power load is evenly distributed (design each build-out to balance the new load), or at least arranged according to a design plan that splits it up more than what you seem to have.
It's possible, since it's less efficient. I know you're run time goes down when you have a unbalanced setup, so it's just as likely IMO that it could draw a bit more power. With that being said, I'm not a power guru.
