# MCC -occupancy type & separation



## wedge (Apr 25, 2014)

Hello, working on the design of an MCC in a predominantly H-3 occupancy.  First question concerns occupancy of the MCC.  Our arch group typically assigns an S-2 to Electrical Rooms.  It is fairly sizeable...so it is not under the 10% threshold for accessory/incidental use.  IBC calls for a 2-Hr separation between and S-2 and an H-3.

Second question:  H-3 is sprinklered.  Client wants no sprinklers in the MCC.  by NFPA 13- Section 8.15.10.1 Installation of Sprinkler Systems, requires sprinklers in all spaces in a building protected with sprinklers, including electrical rooms. According to Section 8.15.10.3, however, sprinklers may be eliminated in electrical rooms if the room is dedicated solely to electrical equipment; only dry-type electrical equipment is used; the equipment is installed in a two-hour fire-rated enclosure including protection for penetrations; and no combustible storage is permitted in the room

Client does not see the reason to rate the partitions at all...

it's 475 sf space...transformers sit outside the space.

Thx!


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## cda (Apr 25, 2014)

Welcome

Translate mcc please

Would not call an electrical room a  "S"

Maybe part of main occupancy or if over for transformer require separation.

Sorry we sprinkle all, normally to include electrical. They do burn

The sprinkler question is one for the ahj


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## wedge (Apr 25, 2014)

thank you!  MCC is Motor Control Center....8' high cabinets.  Sometimes same room will house electrical.


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## cda (Apr 25, 2014)

Yea do not think the ahj will negate the sprinklers

You can ask does not hurt

Not an electrical person, but may want the separation so you do not have to do hazardous area electrical


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## north star (Apr 25, 2014)

*= = : + +*

wedge,

*1st,* ...Welcome to The Building Codes Forum !    

*2nd,* ...the 2 hr. rating is necessary to contain a fire

event in the MCC.......You most definitely do not want

sprinklers in the MCC !..........Water & electricity do not

mix very well, especially for the emergency responders,

or others entering the MCC if \ when the sprinklers

activate..........The Fire Code Official [ FCO ] & the

Building Official [ BO ] can override the adopted code

if they feel \ believe that a definite hazard exists that

would negatively effect their human resources \ staff

upon responding to an event where the sprinklers were

activated in the MCC.

The FCO;  in a certain jurisdiction where I used to

work, required the 2 hr. rated separation on all electrical

rooms & spaces.

IMO, ...I would not put any sprinklers in a MCC, or other

electrical space.

*+ + : = =*


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## cda (Apr 25, 2014)

north star said:
			
		

> *= = : + +*wedge,
> 
> *1st,* ...Welcome to The Building Codes Forum !
> 
> ...


They might also be hurt when they open the door full of hot smoke and sparking electrical

If the electrical is on fire it is fried already


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## north star (Apr 25, 2014)

*/ = / = /*

Most FD's carry infra-red cameras these days, that can detect

a hot door..............If a hot door is detected,  the FD will usually

back up and rethink their plan of attack......Another option

would be to have all electrical power killed to a building, or

to a smaller section of a building rather than to enter an

electrical space with activated \ activating sprinklers.

I still vote NO sprinklers in a MCC or electrical space.

Heck, I ain't even part of the Fire Service either !    

*\ = \ = \*


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## Dr. J (Apr 25, 2014)

1)  I have never seen electrical rooms (or mechanical rooms for that matter) classified as anything other than the occupancy group they are part of.  No need for an S2.

2)  Code is clear – IBC requires a fully sprinklered building per NFPA 13.  NFPA 13 requires a fully sprinklered building to be sprinklered fully, except where omissions are specifically allowed, such as non-combustible shafts, stairs except for the top and bottom, and electrical rooms enclosed in 2 hr FRR construction.

Owner has the choice of rating or sprinklering the room.

The AHJ has no more discretion to require a properly rated electrical room to be sprinklered than they do to require a non-combustible shaft to be sprinklered, unless a specific amendment to NFPA 13 is adopted by the legislative body.


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## wedge (Apr 26, 2014)

Thank you very much Dr. J.

We have had numerous discussions over here concerning assigning an occupancy type to these sort of spaces, especially when they exceed the typical 10% sf incidental/accessory definition.

Regardless, however, I will still be showing the rated partition as an answer for the NFPA 13 requirement (in lieu of sprinklers).  Removing the 'mixed occupancy' definition along with it's rated separation requirements (2hrs between H-3 and S-2) does a lot to clean up my code review.  Thanks again!



			
				Dr. J said:
			
		

> 1)  I have never seen electrical rooms (or mechanical rooms for that matter) classified as anything other than the occupancy group they are part of.  No need for an S2.2)  Code is clear – IBC requires a fully sprinklered building per NFPA 13.  NFPA 13 requires a fully sprinklered building to be sprinklered fully, except where omissions are specifically allowed, such as non-combustible shafts, stairs except for the top and bottom, and electrical rooms enclosed in 2 hr FRR construction.
> 
> Owner has the choice of rating or sprinklering the room.
> 
> The AHJ has no more discretion to require a properly rated electrical room to be sprinklered than they do to require a non-combustible shaft to be sprinklered, unless a specific amendment to NFPA 13 is adopted by the legislative body.


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## north star (Apr 26, 2014)

*( - - - - )*



Section 104.8 in the `12 IFC, allows the Fire Code Official to modify the MCC room

design to not have sprinklers in it.

*[A] 104.8 Modifications:  "*Whenever there are practical difficulties involved in

carrying out the provisions  of this code, the fire code official shall have the

authority to grant modifications  for individual cases, provided the fire code official

shall first find that  special individual reason makes the strict letter of this code

impractical and the  modification is in compliance with the intent and purpose of

this code and that  such modification does not lessen health, life and fire safety

requirements.............The  details of action granting modifications shall be

recorded and entered in the files  of the department of fire prevention."



The "special individual reason" is that in the opinion of the FCO, ...placing

sprinklers in a MCC room; or other electrical room, would pose a greater

hazard to personnel responding to a MCC room or electrical related fire.

[  i.e. - the water would exacerbate the situation  ]......A savvy FCO will

state their position of "having skin in the game" !

If the FCO' decision is challenged, ...the plaintiffs can always chose to go to

court to fight it out, but they will not win !..........I'm pretty sure that case law

will side with the FCO.........It would be a very rare case where the courts

will override FCO in a case like this.

One other thing is the costs !.......If the plaintiffs chose to go to court,

there will be a great amount of additional time & costs associated with their

challenge........Even if the courts were to rule in favor of requiring the

sprinklers in the MCC room, a lot of time & money would have been spent

in the process.

What do you think a business owner will consider as a greater priority ?

[  i.e. - the path of least resistance for their project  ].



*( - - - - )*


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