Electrical Equipment Room Sprinklered?

Q: I was recently informed by an architect that an electrical equipment room does not need to be sprinkled if it has a two-hour fire resistant separation. Have you heard of this and if so, can you tell me where it is permitted?

A: Yes, this is permitted. According to section 19.3.5 of the NFPA 101 Life Safety Code (LSC), 2000 edition, where sprinklers are required, they must be installed in accordance with NFPA 13 Standard for the Installation of Sprinkler Systems (1999 edition). Section 18.3.5 of the LSC for new construction has the same reference to NFPA 13. Section 5-13.11 of NFPA 13 (1999 edition) has an exception that allows the electrical equipment room to be protected with 2-hour fire rated enclosure in lieu of having to be protected with sprinklers. There are a few requirements that must be met when using this exception, though. The room must be dedicated to electrical equipment only, and only dry-type electrical equipment can be used. In addition, the room cannot be used for combustible storage.

Fire Rating for Electrical Rooms

Q: Are electrical equipment rooms required to be fire rated? We have a dry-type transformer in an utility room on one of our nursing units and wanted to know if the room is required to be fire rated.

A: According to the 2000 edition of the Life Safety Code, electrical rooms are not required to be fire rated, although NFPA 13 Standard for the Installation of Sprinkler Systems (1999 edition) does provide an option to provide a 2-hour fire rated barrier around an electrical room in lieu of installing sprinklers (see previous question). But a room that has a transformer in it is regulated by NFPA 70 National Electric Code (1999 edition), article 450-21. This article says any room containing a dry-type transformer which is rated more than 112½ kVA must be 1-hour fire rated. There are some exceptions to this requirement based on the transformer insulation values and vertical mounting. However, transformers that are rated 112½ kVA or less are only required to be separated from combustible materials by 12 inches by a fire resistant heat-insulated barrier. I am aware of some states that require hospital electrical rooms that contain emergency power to be fire rated, so please check with your local and state authorities for their requirements.

Electrical Equipment Room Sprinklered?

Q: Do all electrical rooms have to have automatic sprinklers installed in them? Our electrician tells us there are exceptions to installing sprinklers in an electrical room even when the entire building is required to be sprinklered. Are you aware of these exceptions?

A: The Life Safety Code does not require electrical rooms to be fire rated. However, there are some exceptions which are found in NFPA 13 Standard for the Installation of Sprinkler Systems 1999 edition, section 5-13.11. While this standard requires sprinkler protection in electrical equipment rooms, it does provide an exception in lieu of having to install sprinklers. The room has to be dedicated to electrical equipment only, and only dry-type electrical equipment is allowed in the room. The room has to be protected with 2-hour fire rated barriers with 1½ hour fire rated doors that are self-closing and positively latching. Even though the room is dedicated to electrical equipment only, you are not allowed to have any combustible items stored in the room, which would include cardboard boxes. If you choose to comply with this exception and not install sprinklers in the electrical rooms, then this option does not otherwise cause your building to be non-compliant with any requirement to be fully sprinklered.

112 kVA Transformer in Soiled Utility Room

Q: What are the limitations to installing a 112 kVA dry-type transformer in a soiled utility room? Our local building inspector wants a shield around the transformer separating it from all other contents of the room.

A: According to the LSC, section 9.1.2 requires electrical wiring and equipment to be installed in accordance with NFPA 70 (1999 edition). However, existing installations will be permitted subject to the approval by the AHJ. Section 450-21 of NFPA 70 permits 112½ kVA (or less) dry-type transformers to be installed indoors as long as there is a minimum of 12 inches clearance from combustible materials, or a fire resistant heat-insulated barrier is installed. Transformers over 112½ kVA must be installed in a separate 1-hour fire resistant room. It appears that the transformer in question is permitted to be installed in the soiled linen room, but subject to the approval of the AHJ. If your local building inspector wants the protective fire resistant heat-insulated barrier installed, then that is his prerogative to require it. I suggest you also check with your state authorities to see if they have any further requirements.