electrical room protection

[Rehacayli]

Dear all,
I've found similar questions but not the exact answer. I have 3 electrical rooms with only circuit breakers, UPS and panels inside. According to NFPA 13@s below statement, I don't need to put any sprinkler or protection system inside. Now my question is for the third item. Is that talking about the room or the panels; as the room itself has 2 hours protection but the panels don't have that. Another question is; I've installed CO2 extinguishing system inside the room but because it is dangerous, the owner wants to cancel that. Could anyone tell me how dangerous it is? In the light of these shall I change the protection system or shall I cancel it completely?


8.15.10 Electrical Equipment.
8.15.10.1 Unless the requirements of 8.15.10.3 are met, sprinkler
protection shall be required in electrical equipment rooms.
8.15.10.3 Sprinklers shall not be required in electrical equipment
rooms where all of the following conditions are met:
(1) The room is dedicated to electrical equipment only.
(2) Only dry-type electrical equipment is used.
(3) Equipment is installed in a 2-hour fire-rated enclosure
including protection for penetrations.
(4) No combustible storage is permitted

 

[PEDARRIN2]

Before you do not put sprinkler coverage in these rooms, remember that NFPA 13 is a standard and in the U.S. anyway, requirements are in the respective building code, which will reference the standard. In Ohio, where I am, the Ohio Building Code references NFPA 13, but also states that sprinklers are not to be excluded in rooms just because there is electrical equipment in it. It does allow exclusion if there are generators or transformers.

Carbon dioxide is an asphyxiant and in a small room, could build up to levels which do not support respiration fairly quickly. There are other clean agent types which are not as dangerous. They extinguish fires without lowering the concentration of breathable oxygen below allowable levels.

One is the Ansul "Sapphire" system which is used a lot in data rooms in that it cools and "chokes" the fire, but does not short out the electrical equipment.

If you use water, I would suggest a sidewall sprinkler, not located over equipment, and place a guard over the sprinkler to prevent accidental contact with the sprinkler.

 

[Rehacayli]

thank you for your answer, do you think that by saying "Equipment is installed in a 2-hour fire-rated enclosure including protection for penetrations", are they talking about the panels or the room itself. the room is fairly large(more than 300 m3)and only have electrical equipment. if I don't have to install a protection system and if this is backed up by NFPA, I would like to choose that. so what is your professional opionion. shall i cancel the protection or shall i install a inert gas system etc.

 

[cdafd]

If this is not a critical faculty out the sprinklers in the room.

Electrical panels burn, once they burn those circuits are down anyway.

The exception is the room enclosure has to be two hour rated with any penetrations seals properly, the equipment in side does not have to carry a fire rating

 

[chicopee]

They are talking about the room. When conduits and tubing penetrate the walls, floor and ceiling voids will be created; these voids must be sealed with material that provides an equivalent fire resistance. Bare wiring such as Romex must have some type of shield such as piping in order to penetrate this type of enclosure. I am not sure about BX wiring.

 

[GeorgeMech]

First you have to make sure that all the requirement of NFPA (as mentioned above) regarding on the exclusion of sprinkler protection are ALL met, it is not only about 2 hours fire rating but ALL the above condition shall be met and because if not, you have to protect it with sprinkler system, however, regarding on the decision if whether you want to protect it with sprinkler system or by non-water fire extinguishing system, it's up to the Engineer and / or the client, but if the electrical panels inside are relatively expensive, I would suggest to use clean agent system such as FM-200 and for me, based on the size of the room, I assume this is an occupiable room for which CO2 automatic extinguisher is not appropriate to be used.

 

[Rehacayli]

thank you for your answers. I'm still waiting a decision from the management but these would help a lot.

 

[DavidCR]

Points that comes to my mind.
- Is it really 2hr fire rated? (ok with doors, windows, HVAC, ducts, etc.).
- The penetrations protection shall be a system, it involves the wall, the hole, the penetrating objects and the firestopping material, not only the fire stopping material.
- The room is quite large and I supose the quantity of pannels is big, it may economically deserve a good gas flooding extinguishnig system. CO2 is not dangerous depending if it has a propper NFPA 12 design and 1st class contractor. Other systems can be dangerous too if not well designed. But the decision on the type of system has to consider lots of funtional aspects, and architectural details of the room (elevated floor, type of ceiling, roof, walls, volumes, tightness, etc.).
- If the building has an obvious sprinkler requirement (eg. big occupancy + high rise), it may be better to sprinkler and remember the gas system is not included in that 8.15.10.3.

How dangerous CO2 is?, it is not only a techical or code issue, NFPA12 code includes lots of security, unfortunately it depends a lot on the criteria around it where you live.

Arquitecturally consider that CO2 is heavier than air and goes down, incidents I heard of, deal with the lowers spaces where the CO2 can be trapped out of the obviously protected and inmediate warning area and not properlly vented. And depens a lots of the users/occupancy profiles. So some places present more risk than others.