dual power supplies - on different phases?

[russell thomson]

We have a number of DL380, DL560, ML370 and Netserver lp2000r servers, each with dual power supplies.
We have been told by one vendor that some of these servers cannot have their dual power supplies connected to 2 different phases. Is this correct? If so, which models?

Thanks,
Russell Thomson
Austin Health

[Dusko Milosevic]

Power supplies are AC/DC converters. When the AC current is converted to DC the phases are lost because DC does not have the phase. It is not crucial for the different PWS to use the same phase as they work independently from each other.

Dusko

[Terry Hutchings]

HP's policy is going to say that this is not supported (on any Proliant or Netserver product). It may work for most servers, but not all. Some servers do not handle the conversion in the power supply, but in the power converter module/backplane.

[russell thomson]

Thanks Terry. Is there any way of finding out which models may not be able to use different supplies?

[Jason Beatty]

We have similar servers, and are curious about splitting half of the power supplies to UPS power and the other half to surge-protected non-UPS power. The reason is for fault tolerance in case our UPS fails while normal power is still available. Two UPS units are not feasible at this time.

We were curious if, in systems that have dual power supplies, if the amperage pull is equal between the two, or if one is a primary and pulls the majority of the load, and the other just pulls a minimal amperage as a keep-alive until a possible failover.