Isolated systems for a Hospital OR

[steve66]

A facility has recently realized they have several operating rooms (OR's) that are each fed from one isolated power supply. (ie. a hospital grade isolated power supply with an ungrounded output).

If one of these power supplies lost input power, or if it went bad, that would leave an entire OR completely without power.

So I am considering adding another isolated power supply. I would use this supply to feed half the existing receptacles in each of 2 OR's.

Does anyone have any experience feeding one OR from 2 isolated supplies? Would the neutrals have to be bonded together? Would this create any issues for any of the OR equipment? What if two pieces of equipment were plugged into different supplies, but maybe they have a communication cable that creates a circuti between them? Does that cause any issues?

Finally, I had also considered moving some of the receptacles to a normal grounded supply. But I think that is out for the reasons above (two pieces of equipment could ground the ungrounded supply through a communication cable.)

Any other thoughts or caveats for designing isolated power supplies?

Thanks:
Steve

 

[roger]

Steve per 517.19 O.R.'s must be supplied from more than one source, we do this all the time. The two systems will be completely seperate from one another with the exception of the required bonding of 517.14.

We are frequently using SQ D duplex panels in new rooms, this keeps both Normal and Critical feeders and branch circuit distribution in one enclosure.

Roger

 

[rick hart]

Two correctly installed isolated supplies are not a problem in a single room. They are by definition isolated and duplicates are needed to supply all the equipment in the OR. The bigger problem, if I understand your situation clearly, is several OR's are currently fed from a single power supply.
Are the different OR's monitored by individual LIM's within the OR? 5mA adds up in a hurry as more outlets are being utilized.

 

[steve66]

Roger:

I ran across the square D duplex panel after posting this, and I'm considering using those. I looked in the 1981 code, and apparently two sources were not required back when these OR's were constructed.

Rick:

Each OR currently has 1 and only 1 isolation panel just for that OR. And yes, they each have line isolation monitors.