Building Standards Advisory
Promoting construction of safe, healthy, habitable buildings
Electrical
Question
“When does electrical equipment need to be installed in a room with a fire-resistance rating (FRR)?”
Answer
Where electrical equipment is dielectric liquid-filled and/or in circumstances where protection may be necessary for life
safety, the NBC requires the equipment be installed in a room with a FRR. As most electrical equipment is not dielectric
liquid-filled, or pose life safety risks, the National Building Code of Canada 2010 (NBC 2010) does not generally make
protection in a room with a FRR necessary.
Background
The NBC 2010 prescribes how such components are to be protected and prescribes those instances where a room will
require a FRR. Division B, Article 3.6.1.2. prescribes that the installation of electrical wiring and electrical equipment shall
conform to the requirements of the provincial or territorial regulations, or municipal bylaws, or Canadian Standards
Association (CSA) Standard CSA C22.1 Canadian Electrical Code, Part 1 (the CEC). In Saskatchewan the CEC is adopted by
regulation under provision of The Electrical Inspection Act, 1993 as supplemented by the Saskatchewan Interpretations.
Definition
Although most dielectric materials are solid such as porcelain, glass, plastic, and rubber; liquids may also serve as nonconductors of electricity. According to the Concise Oxford Dictionary 11th Edition, dielectric means having the property of
transmitting electric force without conduction and also means insulating.
NBC Requirements
The major components of a building’s electrical system can be arranged
into three major categories as follows:
1. wiring and raceways
2. power-handling equipment
3. control and utilization equipment
Compliance with The Uniform
Building and Accessibility Standards
Act, Regulations and the National
Building Code of Canada 2010 (NBC
2010) is addressed in this advisory.
Words in italics, other than Act
Of the three components, this advisory will focus on power-handling equipment including transformers, switchboards,
panelboards, large switches, and circuit breakers. Within this category the most common component are panelboards,
commonly referred to as breaker boxes. The NBC 2010 does not require power-handling equipment to be installed in a
service room or within a room designed with a FRR unless adverse conditions exist. The CEC requires that a panelboard
be located so that it is readily accessible and further prescribes that a panelboard must not be located in:
• a cupboard or clothes closet where articles could interfere with access and constitute a fire hazard.
• coal bins where dust can cause short-circuiting.
• bathrooms where shock hazards and short circuiting due to moisture can occur.
• stairways where accessibility is poor.
• high-ambient temperature rooms where nuisance tripping of the overcurrent device can occur along with
deterioration due to the heat of the space.
saskatchewan.ca/buildingstandards | 306-787-4113
Electrical
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dangerous or hazardous locations where there is risk of explosion or fires; or in similarly adverse locations. The
following chart identifies situations when electrical equipment may be required to be installed in a room with a FRR.
The NBC 2010 Division B, Part 3 & Part 9 Service Rooms and Vaults
Type of
Space
Service
Room
Service
Room
Service
Room
Service
Room
Service
Room
Service
Room
Hazardous
Locations
*Vault
Equipment in Space
NBC Reference
FRR of Room
Other
Service equipment
including electrical
equipment
Service equipment
including electrical
equipment
23 L or less of dielectric
liquid in one tank or 69 L
or less in a group of tanks
Service equipment
including electrical
equipment
Service equipment can
share space with electrical
equipment
Sentence
9.10.10.3.(1)
1h
FRR waived where floor area containing the service
room is sprinklered.
Sentence
9.10.10.3.(2)
None
FRR waived where room contains limited equipment
and does not constitute a fire hazard
Sentence
3.6.2.1.(6)
1h
Electrical equipment required to be in a service room
as per the CEC
Sentence
3.6.2.1.(8)
None
Sentence
3.6.2.3.(1)
Generator for emergency
lighting, fire safety and
life safety systems
Electrical wiring and
electrical equipment
Sentence
3.6.2.8.(1)
FRR of room
dependent upon
type of equipment
contained
2h
Equipment is limited and neither constitutes a fire
hazard nor is essential to the operation of life safety
systems
Equipment such as space heating, cooling or water
heating may share space with electrical equipment.
More than 23 L of
dielectric liquid in one
tank and more than 69 L
in a group of tanks
Sentence
3.6.2.7.(2) &
(3)
Sentence
3.3.6.2.(4)
Depending upon
hazard type and
location
3 h FRR if vault is
non-sprinklered
and 2 h FRR if vault
is sprinklered
FRR required where generator and ancillary
equipment is within building
Wiring and electrical equipment may require
additional protection as per the CEC
2 h FRR if building is sprinklered and vault is designed
for no purpose other than to contain electrical
equipment and the vault contains a smoke detector
connected to the building fire alarm system.
*The NBC 2010 Division B, Article 3.6.2.7. prescribes additional safety requirements in the design and construction of an electrical equipment vault. Those
requirements include; explosion relief devices, vents, a separate ventilation system, spill containment and liquid tight design for the floors and wall with a
containment area height of 100 mm to confine spills to the vault.
Where optical fibre cables and electrical wires and cables with combustible insulation, jackets and sheathes are permitted
in a building required to be of noncombustible construction, one prescribed method of protecting wires and cables is to
contain them within a service room separated from the remainder of the building by a fire separation having a FRR of not
less than 1 hour. See the NBC 2010 Division B, Article 3.1.5.18. for additional options for protection.
Protection of electrical conductors may also be required where the conductors are used in conjunction with fire alarms,
emergency lighting, fire pumps, and mechanical systems, serving areas of refuge and contained use areas. Division B,
Article 3.2.7.10. prescribes when electrical conductors require protection such as within a service space with a fire
separation and a FRR.
If there is any uncertainty with respect to the installation and protection of electrical equipment, contact should be made
with SaskPower Electrical Inspection Division for clarification.
Building Standards and Licensing Branch
Building Standards Advisory
100 - 1855 Victoria Avenue
Electrical
Regina, Saskatchewan S4P 3T2
April 2016
(306) 787-4113 Phone
(306) 798-4172 Fax
[email protected]
Original approved and signed by:
www.saskatchewan.ca/buildingstandards
Wm. Hawkins, Executive Director/Chief Building Official
This advisory is published by the Saskatchewan Ministry of Government Relations for purposes of providing information to users on the topic contained herein.
In case of conflict between The Uniform Building and Accessibility Standard Act (the UBAS Act), the National Building Code of Canada 2010 (NBC 2010) and this
advisory, provisions of the UBAS Act and NBC 2010 shall apply.
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