Emergency circuits

[Hoyt]

Hello again,

Project: Clinic - Type B occupancy.

The Owner has requested an emergency generator to pick up the emergency egress lighting, they would also like misc. receptacles, refrigerators, on this generator as well.

I will need two transfer switches - Life Saftey and Equipment branches.

No problems.

But now the Owner has requested some lighitng in some exam rooms, medical storage rooms, and an office on emergency power. I realize, or I believe, I can not put these rooms on the life safety branch because it is not required life safety illumination....so can I simply put the lighting for these rooms on the equipment branch?

Thanks,

Hoyt

 

[nakulak]

is this an existing bldg ? if the existing emergency lighting is already on battery backups and there are no required emerergency systems, you could just install the gen as an optional standby system and save yourself a lot of trouble.

 

[roger]

The exam rooms may be the problem depending on the AHJ's rules.

Roger

 

[Hoyt]

It is a brand new clinic - 9000 square feet.

 

[bcorbin]

is this an existing bldg ? if the existing emergency lighting is already on battery backups and there are no required emerergency systems, you could just install the gen as an optional standby system and save yourself a lot of trouble.

I'm glad you brought up the point of the battery-backed up egress lighting.

Am I correct in that 702.2 would no longer classify this stand-by system as "optional" because the egress lighting is fed from the generator, and would "depend on" the standby system?

And since then, because the task lighting can't go on the life safety or equipment branches, he would either have to install a third transfer switch? I'm voting for the batteries.

 

[Hoyt]

I am confused as to why I can't place it on the equipment branch. Can you give an NEC section that clearifies this for me?

Thanks.

 

[bcorbin]

I guess this being a clinic is making my brain think "health care facility" out of habit. You're right...if the emergency power isn't required, I guess you can put task lighting with the equipment branch. At least I can't find anything in the code that says you can't.

 

[Hoyt]

Yes, I think you are correct. I too was thinking health care at first, but it is a type "B" occupancy and don't see why it could not go on the equipment branch.

 

[831]

But now the Owner has requested some lighitng in some exam rooms, medical storage rooms, and an office on emergency power. I realize, or I believe, I can not put these rooms on the life safety branch because it is not required life safety illumination....so can I simply put the lighting for these rooms on the equipment branch?

Independant of load data:

(2) ATSs requried:

(1) life safety - used to sustain life
(1) optional stand-by - used to back up optional loads; the loads the owner has opted to have backed by a genset.

The AHJ may have a differing/subjective opinion, but that's not my deal.

Depending upon your load, read 517.30(B)(4) too; your installation may qualify.

 

[benaround]

Hoyt,

Have you thought about sending it to the EE and let them design it for you?

1. CYA

2. Might slow the owner down, once you start adding to the gen. seems like

they are not happy until the whole building is on it !!