Sizing UPS and distribution

[johndreher]

For an Information Technology Equipment room, can a UPS system be sized based on actual load rather than nameplate?

Also, NEC article 645.5(A) refers to "connected load" for the branch-circuit conductors, is this refering to actual load or nameplate?

Thanks, John

 

[ron]

Re: Sizing UPS and distribution

You can size the UPS to any load you like. The client might want to have it remain active during full load though. It's designer's choice. If actual load is known give yourself a fudge factor for growth and age degradation.

The connected load is the computed load to which demand factors apply. This connected load value should be very close to actual load, but is calculated prior to the loads installation.