Trying to understanding 3 phase PDUs for a rack

[Anonymous user]

I'm trying to get a layman's understanding to how 3 phase works for PDUs in a rack.

We are installing multiple blade server chassis in a rack and are trying to provide the necessary power/redundancy.

My general question is if I put in a 3 phase 208 30, 50, or 60AMP circuit/PDU into a rack (A and B side) how many Amps are available per phase (L1-L2 plugs, L2-L3 plugs, etc.).

I have read that it's 50amps per phase (really 80% of 50Amps per phase)
I've also read that it's 1/3 of 50Amps per phase (16.6 amps per phase)

If I look at APC's PDU data sheets it varies. A 3 phase 208 50 Amp 7.5Kw PDU says max of 20Amps per phase and the 12.5 KW PDU says 35Amps per phase.

I'm really confused.

[BillP · Accepted solution]

usually their is a breaker on each bank. each bank references two of the phases. did you have any specific model in mind? we can check the breakers on it.

i am not that good with three phase power myself but i do handle the PDUs in general