[labnetwork] electrical advice

[Iulian Codreanu]

Dear Colleagues,

I hope you can provide some sanity checks on the 208 V power panel 
calculations I am doing.

- I get the voltage, number of phases, and what I call full load amps 
from the equipment nameplates, utility specs, installation manuals, etc.
- I calculate the required kVAs (taking into account the number of phases).
- I add up the kVAs for all the tools on my list.
- I assume that, on average, only 50% of the estimated kVA is actually 
used during the tool operation.
- I add 25% of extra capacity.

The above approach yields 660 kVA.

I hope you can weight on:
- Is the "50% current draw" assumption a reasonable one?
- How does 660 kVA compare to your installed capacity?
- Should I allow for a diversity factor (not all the tools will be used 
at the same time) or do you think that the 50% already covers it (the 
cleanroom tools will be on all the time whether or nor they are used)?  
If you think that a diversity factor is OK what percentage would you 
recommend?

Thank you very much for your valuable input!

Iulian

-- 
iulian Codreanu, Ph.D.
Director of Operations, UD Nanofab
149 Evans Hall
Newark, DE 19716
302-831-2784