EXCEPTION MANDITORY OR OPTIONAL to NEC 517.40(A) Applicability

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Rob1

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I have a limited care facility that is a free standing building and it meets the three exception conditions (a), (b), and (c) of NEC Section 517.40 Essential Electrical Systems for Nursing Homes and Limited Care Facilities, Part (A) Applicability. HOWEVER, I would prefer to wire the Genset in conformance with Section 517.40 because the Genset is under 150KW and this would allow me to use only one transfer switch. Section 700.5(D) requires that only emergency loads be on the emergency transfer switch were as Section 517.20 allows emergency lighting (aka Life Safety) to be on the same ATS as critical loads.

So the question is: If a facility meets the three conditions of exception to Applicability to 517.40, can I choose to still wire the facility in conformance with 517.40 rather than Section 700

Perhaps the answer is as simple as by not having a second transfer switch I do not meet condition 517.40(A)(c) ???
 
Rob1 said:
I have a limited care facility that is a free standing building and it meets the three exception conditions (a), (b), and (c) of NEC Section 517.40 Essential Electrical Systems for Nursing Homes and Limited Care Facilities, Part (A) Applicability. HOWEVER, I would prefer to wire the Genset in conformance with Section 517.40 because the Genset is under 150KW and this would allow me to use only one transfer switch. Section 700.5(D) requires that only emergency loads be on the emergency transfer switch were as Section 517.20 allows emergency lighting (aka Life Safety) to be on the same ATS as critical loads.

So the question is: If a facility meets the three conditions of exception to Applicability to 517.40, can I choose to still wire the facility in conformance with 517.40 rather than Section 700

Perhaps the answer is as simple as by not having a second transfer switch I do not meet condition 517.40(A)(c) ???
Click to expand...

If it meets 517.40A exception c, then you have battery packs for the emergency lights? If that's the case, why would you need separate transfer switches? It sounds like the generator would be an optional system.
 
Rob1 said:
I have a limited care facility that is a free standing building and it meets the three exception conditions (a), (b), and (c) of NEC Section 517.40 Essential Electrical Systems for Nursing Homes and Limited Care Facilities, Part (A) Applicability. HOWEVER, I would prefer to wire the Genset in conformance with Section 517.40 because the Genset is under 150KW and this would allow me to use only one transfer switch. Section 700.5(D) requires that only emergency loads be on the emergency transfer switch were as Section 517.20 allows emergency lighting (aka Life Safety) to be on the same ATS as critical loads.

So the question is: If a facility meets the three conditions of exception to Applicability to 517.40, can I choose to still wire the facility in conformance with 517.40 rather than Section 700

Perhaps the answer is as simple as by not having a second transfer switch I do not meet condition 517.40(A)(c) ???
Click to expand...

I don't understand what the issue is. The life safety branch and critical branches are emergency loads. What life safety loads could you have that wouldn't be part of exception C? In other words, if everything is on battery back-up, why do you have a life safety branch?
 
steve66 said:
If it meets 517.40A exception c, then you have battery packs for the emergency lights? If that's the case, why would you need separate transfer switches? It sounds like the generator would be an optional system.
Click to expand...

Section 517.40 (A)Exception Condition (c) Says "An automatic battery operated system(s) OR equipment is provided that shall be effective for at least 1.5 hours and is otherwise in accordance with 700.12...." Section 700.12 also includes as equipment...A GENERATOR. The issue is that under 517.40 I can buy just ONE transfer switch but under section 700 I have to buy TWO transfer switches
 
LIM said:
I don't understand what the issue is. The life safety branch and critical branches are emergency loads. What life safety loads could you have that wouldn't be part of exception C? In other words, if everything is on battery back-up, why do you have a life safety branch?
Click to expand...


Section 517.40 (A)Exception Condition (c) Says "An automatic battery operated system(s) OR equipment is provided that shall be effective for at least 1.5 hours and is otherwise in accordance with 700.12...." Section 700.12 also includes as equipment...A GENERATOR. SO I don NOT have batteries on the lights yet I still meet Condition (c) because I have a generator for the lights. I want to complete the installation using Section 517.40, but the exception uses the mandatory language of "...517.40 SHALL NOT apply to..." It is kind of stupid, IF you meet condition (a) and (b) and IF you have a generator for emergency lights it seems to indicate you MUST comply with Section 700 and MUST not use Section 517.40.

The issue is that under 517.40 I can buy just ONE transfer switch but under section 700 I have to buy TWO transfer switches
 
Rob1 said:
Section 517.40 (A)Exception Condition (c) Says "An automatic battery operated system(s) OR equipment is provided that shall be effective for at least 1.5 hours and is otherwise in accordance with 700.12...." Section 700.12 also includes as equipment...A GENERATOR. SO I don NOT have batteries on the lights yet I still meet Condition (c) because I have a generator for the lights. I want to complete the installation using Section 517.40, but the exception uses the mandatory language of "...517.40 SHALL NOT apply to..." It is kind of stupid, IF you meet condition (a) and (b) and IF you have a generator for emergency lights it seems to indicate you MUST comply with Section 700 and MUST not use Section 517.40.

The issue is that under 517.40 I can buy just ONE transfer switch but under section 700 I have to buy TWO transfer switches
Click to expand...

OK, that makes sense.

I'm looking at the 2014 Code, and 517.41(B) allows the critical branch and life safety branch to be served by a single ATS when the demand is less than 150 KVA. However, the items that can be placed on these branches are limited to the items listed in 517.42 and 43.

It sounds like you have other "optional" items that the owner would like on the generator. (Items not listed in 517.42 and 43.) I believe you need a separate transfer switch to serve those items.
 
Its this simple, if all the loads are allowed on the critical or life safety branch then you can use 1 ATS. If you have loads that the engineer or LCF decided are on the normal branch, but need back-up, then you need two.
 
LIM said:
Its this simple, if all the loads are allowed on the critical or life safety branch then you can use 1 ATS. If you have loads that the engineer or LCF decided are on the normal branch, but need back-up, then you need two.
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Are you Sure? I understand what you are saying, but how do you get around the mandatory language used in the Exception that decides IF Section 517.40 even may be applied to the building? Because IF Section 517.40 does NOT apply then I must use Chapter 7. If I use Chapter 7 then all the Life Safety Loads are instead covered by Section 700 and all the Critical Loads are instead covered by Section 701 and 700.5(D) says they may NOT share a transfer switch.

So backing up to the section that decides is Section 517.40 applies....it reads:

517.40(A) Applicability. The requirements of Part III, 517.40(C) through 517.44 shall apply to nursing homes and limited care facilities
EXCEPTION: The requirements of Part III, 517.40(C) through 517.44 shall NOT apply to freestanding buildings used as nursing homes and limited care facilities, provided that the following apply:
(a) (my summary, no life support equipment) This is Applies in my case
(b) No surgical treatment requiring general anesthesia is offered. This applies in my case.
(c) An automatic battery-operated system(s) OR equipment that shall be effective for at least 1.5 hours and is otherwise n accordance with 700.12 and is capable...blah..blah IF I INSTALL A GENERATOR WHICH IS EQUIPMENT LISTED IN 700.12 AND I USE IT FOR EMERGENCY LIGHTING, then it appears as though I also comply with this

IF SECTION 517.40 does not apply then I have to use Chapter 7 for the Genset and then I need two switches.

So my original question remains, if the code uses mandatory language in a exception (SHALL NOT) does that mean the exception MUST be used or does it mean the inspector must accept it if I choose to use it. The weird thing here is the way I read it, if (a) and (b) of the exception apply and you use a generator for Life Safety loads then code says you cannot call them Life Safety loads and must wire per Chapter 7.
 
steve66 said:
OK, that makes sense.

I'm looking at the 2014 Code, and 517.41(B) allows the critical branch and life safety branch to be served by a single ATS when the demand is less than 150 KVA. However, the items that can be placed on these branches are limited to the items listed in 517.42 and 43.

It sounds like you have other "optional" items that the owner would like on the generator. (Items not listed in 517.42 and 43.) I believe you need a separate transfer switch to serve those items.
Click to expand...

Please see my reply to LIM, that explains the question better I think
 
Rob1 said:
Are you Sure? I understand what you are saying, but how do you get around the mandatory language used in the Exception that decides IF Section 517.40 even may be applied to the building? Because IF Section 517.40 does NOT apply then I must use Chapter 7. If I use Chapter 7 then all the Life Safety Loads are instead covered by Section 700 and all the Critical Loads are instead covered by Section 701 and 700.5(D) says they may NOT share a transfer switch.

So backing up to the section that decides is Section 517.40 applies....it reads:

517.40(A) Applicability. The requirements of Part III, 517.40(C) through 517.44 shall apply to nursing homes and limited care facilities
EXCEPTION: The requirements of Part III, 517.40(C) through 517.44 shall NOT apply to freestanding buildings used as nursing homes and limited care facilities, provided that the following apply:
(a) (my summary, no life support equipment) This is Applies in my case
(b) No surgical treatment requiring general anesthesia is offered. This applies in my case.
(c) An automatic battery-operated system(s) OR equipment that shall be effective for at least 1.5 hours and is otherwise n accordance with 700.12 and is capable...blah..blah IF I INSTALL A GENERATOR WHICH IS EQUIPMENT LISTED IN 700.12 AND I USE IT FOR EMERGENCY LIGHTING, then it appears as though I also comply with this

IF SECTION 517.40 does not apply then I have to use Chapter 7 for the Genset and then I need two switches.

So my original question remains, if the code uses mandatory language in a exception (SHALL NOT) does that mean the exception MUST be used or does it mean the inspector must accept it if I choose to use it. The weird thing here is the way I read it, if (a) and (b) of the exception apply and you use a generator for Life Safety loads then code says you cannot call them Life Safety loads and must wire per Chapter 7.
Click to expand...

I just received a Informal Interpretation back from NFPA on this question. The answer was as follows:

"The main rule applies and it is permitted to be wired as required by the main
rule. The exception allows for an optional method providing the
conditions apply. The exception is simply stating that the main rule does
not have to apply (or be followed) if the conditions are met in the exception."
 
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