Max current through a 30A PDU

[Anonymous user]

Hi all,

We've got a 30A drop into our cabinet and need to make the most of the available power. After speaking with the APC techs, it seems there is no good answer to just how much we can pull through our AP7932. The "Regulatory Derated Input Current" is 24A, I understand that's the NEMA derating to 80% of nominal. Still, leaving 20% of the available power on the table is just not going to cut it. Pretend that we can control spikes in current draw. Does anyone know how much we can reliably pull through this 80% solution before the breakers go POP and send us back to the stone age?

Are there any PDUs out there that will let us pull the full 30A?

Thanks,
Peter

[K-Dog_apc]

Someone from APC will probably have to answer your question on the rack PDU but I would suggest the first bottleneck is the circuit breaker feeding the RPDU. If it is a typical installtion of a whip coming from a 20, 40 or 80kw Symmetra XPDU frame you are feeding it with a SquareD circuit breaker that is rated for 80% continuous duty. You might want to explore replacing this with a 100% rated cb assuming the RPDU is 100% continuous also. Having said that I have seen people run these breakers an amp or 2 over 100% rating for a long time but I would not recommend this under any circumstances. The safest solution from an uptime stand point would be to add a second RPDU for redundancy.

Message was edited by: K-Dog

[Anonymous user · Accepted solution]

Not only that, it's a code. Anything that will operate for 3 hours or more is considered "continuous duty" and only allowed to use 80% of the capacity. Something like a hair dryer is considered "temporary". IT equipment are "continuous load".