Coordinate Requirements Emergency Generators

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Chapter 7 requirements for Generators which feed both Emergency Egress lighting (covered by Section 700) and other non-emergency loads, including Legally required loads (Section 701) and optional (Section 702) are not consistent with requirements for the similar situation for Nursing Homes and Limited Care Facilities (Section 517.40) in the following way:
For gensets under 150 KW, a Health Care Facility covered by 517.40 can install one transfer switch for all load types.
For all gensets used in any other occupancy, if you have Emergency Lighting on the genset (the most common load) and you have other required or not required loads you want on the genset, you MUST install two transfer switches.

Code Suggestion:
Clarify in the Code why this is because it seems counter intuitive, OR make them the same. Why is it Okay for a Nursing Home or Limited Care facility to have it's lighting (or Life Safety related emergency loads) connected in a less reliable way than other occupancy types? Why not have the 150KW exception for all occupancies or require two switches for all occupancies.

Also, clarify that Section 700 applies to all lighting on a genset put in to meet the requirements of emergency egress lighting in the building code. Too many people assume that this lighting is covered by Section 701 including inspectors who rarely enforce the duel transfer switch requirement caused by Section 705(D)
 

LEO2854

Esteemed Member
Location
Ma
Chapter 7 requirements for Generators which feed both Emergency Egress lighting (covered by Section 700) and other non-emergency loads, including Legally required loads (Section 701) and optional (Section 702) are not consistent with requirements for the similar situation for Nursing Homes and Limited Care Facilities (Section 517.40) in the following way:
For gensets under 150 KW, a Health Care Facility covered by 517.40 can install one transfer switch for all load types.
For all gensets used in any other occupancy, if you have Emergency Lighting on the genset (the most common load) and you have other required or not required loads you want on the genset, you MUST install two transfer switches.

Code Suggestion:
Clarify in the Code why this is because it seems counter intuitive, OR make them the same. Why is it Okay for a Nursing Home or Limited Care facility to have it's lighting (or Life Safety related emergency loads) connected in a less reliable way than other occupancy types? Why not have the 150KW exception for all occupancies or require two switches for all occupancies.

Also, clarify that Section 700 applies to all lighting on a genset put in to meet the requirements of emergency egress lighting in the building code. Too many people assume that this lighting is covered by Section 701 including inspectors who rarely enforce the duel transfer switch requirement caused by Section 705(D)

Seems to be a lower priority..
 

iwire

Moderator
Staff member
Location
Massachusetts
For gensets under 150 KW, a Health Care Facility covered by 517.40 can install one transfer switch for all load types.

Not all load types, only the critical and life safety branches of the 'essential electrical systems'. You can't power the TV in the waiting room with that one transfer switch.

To power the TV a second transfer switch would have to be added for those optional standby loads.





For all gensets used in any other occupancy, if you have Emergency Lighting on the genset (the most common load) and you have other required or not required loads you want on the genset, you MUST install two transfer switches.

I do not see it that way if all you have is emergency loads, lighting, elevator, fire control panel, smoke evac. etc. all that may well be on the emergency transfer switch together.

If you wanted to add power for a server rack than another switch would be needed.


clarify that Section 700 applies to all lighting on a genset put in to meet the requirements of emergency egress lighting in the building code. Too many people assume that this lighting is covered by Section 701 including inspectors who rarely enforce the duel transfer switch requirement caused by Section 705(D)

I can tell you in my area it is already enforced. :)

We almost never apply 701, around here it would be 700 or 702.
 

roger

Moderator
Staff member
Location
Fl
Occupation
Electrician
Why is it Okay for a Nursing Home or Limited Care facility to have it's lighting (or Life Safety related emergency loads) connected in a less reliable way than other occupancy types? Why not have the 150KW exception for all occupancies or require two switches for all occupancies.


One reason is the Life Safety and Critical branches are both "crash and burn systems" meaning they are both "Emergency" systems and it wasn't too many years back they were one and the same in all health care facilities.

Another reason for consideration could be that health care facilities staff are normally trained for emergency situations.

Take note that the less than 150 KVA rule also applies to small hospitals and you can add the "Equipment Branch" into the mix. If I were designing this system I would definitely include load shedding for the Equipment Branch.

Roger
 
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