medical equipment

[john37]

I needed someone's opinion if it's not a good idea to put an air handler unit load on a panel that has medical equipment such as mommograms, x-ray machine, etc.
I have a project now where I have limited power sources so I'm trying to figure out the best way to provide power to all the medical equipment and a/c loads. Ideally if I could put in on one 480/277V, 3 ph panel that would be good, but I'm not sure if it's a good idea to put an a/c load on the panel.
Thanks.

 

[jimday]

5.17 does not address it specifically except to say that mechanical equipment must be connected to the equipment branch. I believe x-ray and imaging equipment can be connected to either the critical branch or equipment branch. It may depend on the state your in since most states have additional requirements to the NEC. Personally I would try not to connect HVAC loads to a panel with medical eq. since some imaging equipment can be quite sensitive.

 

[john37]

Thanks Jimday. In my case, we have a doctors office located in an office building so there is no critical power or even a back up generator in the building. (It's a very old building). I agree, that it is not a very good idea to connect a HVAC load on the panel, but in my case I may have no other option unless there is anywhere in the code that specifically states that I can not. I'll check our local codes as well. Thanks.

 

[wirenut1980]

I echo concerns that medical imaging equipment is pretty sensitive to voltage sags. Depending on the size, the air handling unit could be a "sag generator" if you get my drift.

I don't know of any code restrictions, but you might end up getting called back to install either sag mitigation at the imaging devices or some type of soft start at the AHU. Have you determined how much the AHU will sag the voltage when starting up? It might be wise to calculate that and then talk with the imaging equipment manufacturer to see if it might be a problem.

 

[steve66]

If its just a standard "doctor's office xray", as long as the voltage drop isn't too great (like wirenut mentioned), they should be OK on the same panel.

I have designed a lot of doctor's offices. Most have a single 200A panel. So the cooling equipment and the XRAY both wind up on the same main panel.

Now if it were a CT unit that takes a series of xrays, that might be a different story.

And you can always ask the Xray vendor's opinion before you connect it.

Steve

 

[john37]

Thanks guys....wirenut that's a good suggestion. I'll do that. This particular office building I'm working in is a mess Electrically. There are main breakers, branch circuits on different floors feeding other floors. It's a real heachache. I appreciate your opinions.