Calculating Critical Branch Loads

[steve66]

If I use table 220 to calculate the load on a critical branch panel in a hospital, can I reduce the required load by the portion of the load that is on the critical branch?

For example, 2VA/SF is required for a hospital lighting load. But less than half the lighting is on the critical branch. So can I use 1VA/SF for the critical branch, and assume the other 1VA/SF is provided by the normal panel?

Steve

 

[roger]

Re: Calculating Critical Branch Loads

Steve, as an electrician talking to an engineer (so take this for what it's worth) I don't see why not.

Under normal conditions all is being fed from the Normal System in the first place. Under generator power, "Task Illumination" is all that is required.

What is the extent or level of "Task Illumination" I don't know.

In Critical care areas I would think it should be at least 75% of the full design capacity.

Other areas should have enough for the personel to perform a reduced level of patient care and neccessary tasks safely.

Roger

[ August 23, 2004, 06:58 PM: Message edited by: roger ]