Delivery Room and Isolated Power

[elecshop]

I am working on a delivery room that has the following loads:

• On anesthesia boom: receptacles on critical branch circuit, receptacles on normal branch circuit
• On walls: general purpose receptacles on a normal branch circuit
• 4 dedicated critical circuits for 4 equipment in the room
• Surgical light on critical branch, dedicated circuit
• 2x4 ceiling lights on the critical branch circuit

The total load on the critical branch would be around 3kVA, and on the normal branch would be around 2kVA. I am trying to figure out the size of the isolation transformer(s). Also note that the normal power system is backed up by the generator through a separate ATS. I hope you can help me by answering the following questions:

1. The normal receptacles also require and isolation panel, right? Because of their location in a "wet procedure location".
2. I couldn't find a specific requirement in NEC 517.33 & 517.34 that prevents general purpose receptacles in a critical area from being on the normal branch, as those articles only include specific receptacles. Can you confirm?
3. Is it acceptable to have two isolation panels, one fed from a normal branch 208/120V panelboard and one fed from a critical branch 208/120V panelboard? Maybe 5kVA each?
4. The 2x4 lights are not required to be on isolated panels, and this circuit is shared with other lights in a nearby room. I don't think this would be a code violation, will it?

Thanks!

 

[roger]

#1 Yes
#2 Yes, they can be on the Normal Branch
# It would be required, read 517.19. Check into SQ D Dual Isolation Panels, other manufacturers also make them.
# No problem but in my experience there would be both Normal Branch and Critical Branch lighting circuits in these spaces.

Along with the Critical Branch Lighting you will need at least one battery powered EM fixture.

Please update your profile to show a more accurate location, it helps others when responding.

 

[elecshop]

#1 Yes
#2 Yes, they can be on the Normal Branch
# It would be required, read 517.19. Check into SQ D Dual Isolation Panels, other manufacturers also make them.
# No problem but in my experience there would be both Normal Branch and Critical Branch lighting circuits in these spaces.

Along with the Critical Branch Lighting you will need at least one battery powered EM fixture.

Please update your profile to show a more accurate location, it helps others when responding.

Thanks Roger. I updated my location.

For the battery powered EM fixture, 517.63(A) says it should be ahead of switching, but does it have to be always on? Or it would turn on only when the power supply of the lights on the same circuit goes off? From the definition of battery powered lights, it says "Relaying device arranged to energize the lamps automatically upon failure of the supply to the unit equipment" so I guess it goes on only when the branch circuitry power supply is off (i.e. the critical branch ATS does not switch to generator power or something else goes wrong).

Also, control of critical branch lights is permitted, so I am planning to install an occupancy sensor with a wall station for dimming/manual control, to comply with Ashrae 90.1 for energy efficiency. But I'm hesitant about dimming in an OR although method of control is not mentioned in code. What do you think?

 

[sgtsparky]

Remember that the NEC is only one of your requirements 70. , 99., 101 and the joint commission for hospital accreditation,

Make sure you have your Preventative maintenance checks for the isolation panel(s)!

My lights are 277 they do have hard wired controllers but have a sense line that connects to the supply so when the power is interrupted they automatically switch to battery’s.

Watch out for emergency lighting as some battery lights have overload sensors and if this is your only egress lighting they do not meet code (I recently ran into this and ended up adding a battery egress light) with an OR remodel the L&D rooms have the same requirements

I would use caution especially with critical care areas combining rooms on one circuit for lighting. A fault in one room can take down another room or when working in one room having to power down both.

As others have said yes & yes there can be normal power in the room and the critical power that is on generator power those receptacles will be red hospital grade as I am sure you are aware.

There is a difference in care designation but since you mentioned surgical lighting this room requires critical care requirements

The basics are the egress lighting is immediate, e-lighting can take up to 10 seconds by code, both hospital systems I have worked in have only a blink at worst in the critical lighting systems but code allows 10 seconds and is required to be tested monthly at a minimum quarterly, 30& 90 second tests.

I would recommend never connecting 2 critical spaces on the same branch circuit Lawyers would have a field day if one room caused a fatality or could be linked to a reason…

Egress lighting done by zones makes testing easier, there should be engineering stamped or in my state a supervising general journeyman sign off on the plans employed by the hospital/ system, you don’t want to end up with legal issues for missing one of the many hospital requirements

 

[elecshop]

Watch out for emergency lighting as some battery lights have overload sensors and if this is your only egress lighting they do not meet code (I recently ran into this and ended up adding a battery egress light) with an OR remodel the L&D rooms have the same requirements

So an OR room and a L&D room would require an emergency lighting unit, connected to the same critical branch circuit, but ahead of the local switches, so they would turn on upon loss of the other power in the room, right?

I would use caution especially with critical care areas combining rooms on one circuit for lighting. A fault in one room can take down another room or when working in one room having to power down both.

Noted.

As others have said yes & yes there can be normal power in the room and the critical power that is on generator power those receptacles will be red hospital grade as I am sure you are aware.

Noted, however note that in this project (we are renovated existing) the normal power will also be backed up by generators - a new ATS will be added.

Thanks!