Assuming motor loads -calculations-

[smilieface]

I am working on a project on short circuit study. I am using SKM. I do have two MCC's (two buses) but I do not have motor loads information. I would like to include assumed motor loads at each bus supplying motors to account for motor contributions to the short circuit current. What would be a conservative assumption to each MCC?

1hp=1 KVA
xfmr=norminal 1500KVA, full load=2000KVA
breaker supplying the MCC=600A

If I take 80% of the ampere rating of the breaker supplying the MCC, what would be the motor load in hp? :-?

I'd appreciate it if someone could show me calculations. Thank you for your help in advance.

 

[skeshesh]

In my opinion, this is sort of like saying you don't have the question and you want to assume some numbers and calculate the answer. The system charactersitics would be effected by not just total load but number of motors, size of each motor, etc. I understand that at times information is simply unavailable, but there are times that you have to stand firm and tell the boss or the client that you need the information or the study won't be very useful.