I'm moving into a new building and need to order some new PDUs. The new setup is a 208v 3-phase wye setup. I don't know much about 3-phase, everything I have read online essentially says it's counter-intuitive for lay-people and generally confusing.
I have 110 machines that pull a maximum of 1050W each. For my purposes I need to assume that they are running at full power 24/7. The power supplies are pretty standard and will run up to 240 (but I'm assuming because the 3-phase is 208v that is also the voltage that comes out of the PDUs?).
I'm looking at these PDUs: APC AP7998
http://www.apc.com/resource/include/techspec_index.cfm?base_sku=AP7998
Supposedly these are 12.5 kW broken down into three branches, each of which has a 20amp breaker. Would these sustain a constant load of just under 20amps? How many PDUs would I need to run 110 of these machines?
Here's my calculations but I don't know if they are correct (and since I don't understand 3P very well they probably are) so if anyone can help out I'd appreciate it.
1050W / 208v = 5.048 a
now if I run four that would be 20.192 amps which is just over and presumably enough to trip the breaker. so if I run three machines per branch:
3 * 5.048W = 15.144 a
that looks like it will be ok. With 3 machines per branch and 3 branches per PDU that is 9 machines per PDU. 110 / 9 = 12.222.
So I'd need 13 of those PDUs to power 110 machines at 1050W each?
The PDU does say 35a per line though so for 3phase would that really translate to 105amps or 21.8kW?
I have 110 machines that pull a maximum of 1050W each. For my purposes I need to assume that they are running at full power 24/7. The power supplies are pretty standard and will run up to 240 (but I'm assuming because the 3-phase is 208v that is also the voltage that comes out of the PDUs?).
I'm looking at these PDUs: APC AP7998
http://www.apc.com/resource/include/techspec_index.cfm?base_sku=AP7998
Supposedly these are 12.5 kW broken down into three branches, each of which has a 20amp breaker. Would these sustain a constant load of just under 20amps? How many PDUs would I need to run 110 of these machines?
Here's my calculations but I don't know if they are correct (and since I don't understand 3P very well they probably are) so if anyone can help out I'd appreciate it.
1050W / 208v = 5.048 a
now if I run four that would be 20.192 amps which is just over and presumably enough to trip the breaker. so if I run three machines per branch:
3 * 5.048W = 15.144 a
that looks like it will be ok. With 3 machines per branch and 3 branches per PDU that is 9 machines per PDU. 110 / 9 = 12.222.
So I'd need 13 of those PDUs to power 110 machines at 1050W each?
The PDU does say 35a per line though so for 3phase would that really translate to 105amps or 21.8kW?
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