Electrical equipment in service rooms – continuation of the discussion - By: Ark Tsisserev, P.Eng.

Written By Guest User

I’m encouraged by the feedback from the readers on my articles related to electrically connected life safety system.

This article contains compilation of questions regarding electrical equipment in service rooms and provides answers based on the relevant requirements of the National Building Code of Canada (NBC) and the Canadian Electrical Code, Part I (CE Code).

It should be noted that 2015 edition of the NBC and 2021 edition of the CE Code are used in this article for the reference purpose.

Question 1: Are panelboards always required to be in service rooms?

Answer to question 1: “NO”. Except for Sentence 3.6.2.1.(6) of the NBC, which states the following: “3.6.2.1.(6) Electrical equipment that is required to be located in a service room according to CSA C22.1, “Canadian Electrical Code, Part I, shall be installed in a service room separated from the  remainder of the building by a fire separation having a fire-resistance rating not less than 1 h.”, the NBC does not have any specific restrictions limiting installation of panelboards or other electrical equipment to services rooms only. Panelboards are routinely installed on floor areas of a building, and service rooms for electrical equipment are utilized by electrical designers for convenience of operation and maintenance of electrical equipment. Of course, when a life safety distribution or utilization equipment (e.g. equipment for smoke control and smoke venting, fire pump equipment, fire fighters’ elevator equipment, etc.) is installed in a building, or where certain electrical equipment containing dielectric liquid is installed in a building, it must be located in fire rated service rooms – to assure operation of this equipment under exposure to fire. (See answers to questions 2 and 3 below.)

 

Question 2: Are service rooms containing electrical equipment always required to be fire rated?

Answer to question 2: “NO” The NBC mandates that only the life safety distribution and utilization electrical equipment, which is connected from the emergency power supply source by conductors required by Article 3.2.7.10. to be protected against exposure to fire, must be in fire rated service rooms. Sentence 3.2.7.10.(1) of the NBC states the following:

“ 3.2.7.10.(1) The protection of electrical and emergency conductors referred to in Clauses (a) to (c) shall conform to the requirements stated in Sentences (2) to (11):

a) electrical conductors located within buildings identified in Article 3.2.6.1. serving

i) fire alarms,

ii) emergency lighting, or

iii) emergency equipment within the scope of Articles 3.2.6.2. to 3.2.6.8.,

b) emergency conductors serving fire pumps required to be installed under Article 3.2.5.18., and

c) electrical conductors serving mechanical systems serving

i) areas of refuge identified in Clause 3.3.3.6.(1)(b), or

ii) contained use areas identified in Clauses 3.3.3.7.(4)(a) and (b).“

Article 3.2.7.10. of the NBC explains the extent of fire protection of these emergency conductors and clarifies that If the distribution panel and the utilization equipment it serves are within the same room, only the electrical conductors leading up to the distribution panel need to be protected. It is assumed that the distribution panel and the equipment it serves are within sufficient proximity to each other such that a fire in the same area of origin would affect both. This NBC Article also explains that to ensure continuous operation of the fire alarm and voice communication systems in a high-rise building for a sufficient duration of time to control and direct the evacuation of building occupants, a level of protection is required for those electrical conductors interconnecting the major elements of the fire alarm system. As such, it permits the protection of electrical conductors to be waived for portions connecting a transponder or fault isolation device to fire alarm input devices (fire detectors, manual stations, etc.) or a voice communication transponder to a fire alarm audible signaling device, provided all circuits or portions of the circuits are contained within the same storey.  It should be noted that a few of my earlier articles were dedicated to protection of electrical conductors against exposure to fire.

 

Question 3. Is certain electrical equipment required to be in the fire rated service room by the CE Code?

Answer to question 3 “YES”  The CE Code recognizes that only dielectric liquid filled equipment must be located in an electrical equipment vault or in a