Selective Coordination for HVAC equipment in hospital

[lindstrom]

2005 NEC. 700.27 states that "Emergency system(s) overcurrent devices be selectively coordinated". Figure 517.30 No.1 sketch shows the equipment system as part of the "Essential Electrical System" but outside of the Emergency electrical system.

Is the HVAC equipment system required to be part of Selective Coordination?

 

[charlie b]

517.30(B)(3) - 2005 edition - talks of equipment that is necessary for patient care and basic hospital operation. I think that would include HVAC, and I infer that that makes HVAC a "legally required standby" load, as defined in 701. Therefore, 701.18 brings selective coordination into play. So my answer is yes.

 

[volt101]

Check out 517.26 (new to the 2005), it states that essential electrical system shall meet the requirements of Article 700, except as modified by Article 517.

They chose their words carefully. If they didn't call out "essential systems" then small essential systems would not have to meet the 700 standards since a 150kVA system or smaller does not have an "Emergency System" as shown in figure 2 of 517.30

So, Yes, they have to be selectively coordinated....

 

[erickench]

From a practical view point selective coordination is always a good thing but NEC 517.30(B)(2) state's:

The emergency system shall be limited to circuits essential to life safety and critical patient care.

This is the amendment as mentioned in NEC 517.26. The essential electrical system includes the equipment plus the life safety and critical care branches. No I do not see an NEC requirement for the equipment circuit's OCPD being selectively coordinated as an emergency system. However, Charlie does present a good case for the HVAC being a Legally Required Standby system.
Look at the fine print note under NEC 701.2.