Tap off of elevator ATS for equipment power

[Bob Ruhe]

I have a boiler for domestic hot water in a skilled nursing facility. It is currently on regular power but they would like it placed on emergency power. Nearby there is a critical branch ATS with a 200 amp 3 phase 208 volt feeder for a 125 amp elevator disconnect as it's only load. I am trying to figure out if it would be permissible to tap out of the ATS and place a 60 amp 3 phase sub panel beside it to power the boiler. Can anybody help? Thanks.

 

[don_resqcapt19]

I don't see the domestic hot water as a load that is permitted to be connected to the essential electrical system. See 571.43.

 

[Bob Ruhe]

That was my suspicion. Thanks for the help and the code reference, Don. Great Forum.

 

[LIM]

I don't see the domestic hot water as a load that is permitted to be connected to the essential electrical system. See 571.43.

I think you were referring to 517.43, and if the facilities risk assessment team deems that a loss of hot water could cause discomfort to residents/patients, I see no problem connecting this load to the critical branch. 517.43(B)(3) allows the connection of additional equipment. I would also confirm with an electrical engineer that you are not overloading the Generator or affecting the load shedding properties if deciding to connect at that point.

 

[don_resqcapt19]

Yes, it should have been 517.43.
The rules use the term "shall be permitted" so you are correct that the code wording does not preclude the connection of other loads.

 

[Bob Ruhe]

Thanks for the replies, gentlemen.

Checked back there today and there is only Life Safety and Critical branches on the generator, no 'equipment branch' to pull from. I am told the generator has ample capacity; typically using only 20-30% of it's capacity.

My reading of 517.43(B)3 seems to say it would be OK. Perhaps I will run it by the inspector and/or an engineer.

 

[LIM]

Thanks for the replies, gentlemen.

Checked back there today and there is only Life Safety and Critical branches on the generator, no 'equipment branch' to pull from. I am told the generator has ample capacity; typically using only 20-30% of it's capacity.

My reading of 517.43(B)3 seems to say it would be OK. Perhaps I will run it by the inspector and/or an engineer.

Most of the time in a Nursing Home/Assisted Living Facility you are going to only have LS and Critical Branches unless otherwise spec'd by the engineer. In hospital settings the equipment branch is much more common. In 517 be sure you check the right sections, as some apply to hospitals and others apply to everything else. Good luck on this project and I hope it works out well for you.

 

[kwired]

Thanks for the replies, gentlemen.

Checked back there today and there is only Life Safety and Critical branches on the generator, no 'equipment branch' to pull from. I am told the generator has ample capacity; typically using only 20-30% of it's capacity.

My reading of 517.43(B)3 seems to say it would be OK. Perhaps I will run it by the inspector and/or an engineer.

If you do connect this DWH, and connect it as an equipment branch item you would need to establish the "equipment branch" and not just pop a breaker into a panel that is part of life safety or critical branches.

 

[steve66]

Sounds like your facility is probably below the 150KW limit noted in 517.41(B). Therefore, a single ATS is permitted to serve multiple branches.

Also, if it is a nursing home or limited care facility (517.40), LIM is correct. There are only Life Safety and Critical Branches, no equipment branch. In that case, I think putting the HWH on the critical branch is fine, if that's what the facility wants.

If it is a hospital, or if it has critical care that requires 3 separate branches, you are probably still under the 150 KW limit (This time the code reference is 517.40(B)(4). That means you can feed all 3 branches from a single ATS, but the 3 branches need to be separated after they leave the ATS (separate feeders to separate panels). But it sounds like your tap from the ATS would comply.