Powering a Fire Alarm System: What CEC Section 32 Requires

Sources checked August 2026

Quick answer

• Section 32 covers local fire alarm systems, permanently connected smoke and CO alarms, and fire pumps
• It is supplementary: it amends the general rules rather than replacing them
• Dedicated circuit, with a permanently marked RED disconnect lockable in the ON position
• Copper conductors, minimum 300 V insulation rating
• Independent of all other wiring: no sharing a raceway with lighting or power
• Class 1 treatment regardless of voltage, because it is a safety control circuit
• In Ontario: the 2024 OESC (29th edition), in force 1 May 2025

Why this is stricter than you might expect

A fire alarm circuit runs at 24 volts. It draws very little current. Every instinct built from ordinary control wiring says: treat it as low voltage, Class 2, and get on with it.

That instinct is wrong in Canada, and there is a specific rule that makes it wrong.

Rule 16-010 (commonly cited) requires that circuits to safety control devices, where failure would introduce a direct fire or life hazard, be treated as Class 1 circuits regardless of voltage or power limitation. (IAEI Magazine, Canadian column)

A fire alarm system is exactly that kind of device. So the Class 2 allowances a technician might expect (the relaxed separation rules, the lighter wiring methods) do not apply.

If you have come from American practice, this is one of the sharper divergences. It is not that Canada is fussier for its own sake; the Canadian code makes the reasoning explicit and then applies it consistently.

What Section 32 covers

Section 32 applies to local fire alarm systems, permanently connected smoke and carbon monoxide alarms, and fire pumps. It is a supplementary section, meaning it amends the general rules of the code rather than standing alone. (Electrical Industry News Week)

The requirements

A note on rule numbers. The requirements below are well attested across Canadian sources. Several of the rule numbers come from secondary guides whose CEC edition is not stated. Treat the requirement as solid and verify the number against your own copy of the OESC before citing it in a compliance document.

Conductors: commonly cited as Rule 32-100

Note the 300 V insulation rating. Ordinary Class 2 control cable is frequently rated lower. Using it on a fire alarm circuit is a common and entirely avoidable failure.

Wiring method: commonly cited as Rule 32-102

Permitted methods:

• Totally enclosed metal raceway
• Metal-armoured or metal-sheathed cable
• Rigid non-metallic conduit
• Electrical non-metallic tubing (ENT): but in combustible construction, ENT requires embedment in at least 50 mm of masonry or concrete

The theme is mechanical protection. A fire alarm circuit has to survive the building around it, including, up to a point, the early stages of a fire.

Separation: commonly cited as Rule 32-102(3)

This one produces more field arguments than any other.

Fire alarm conductors must be kept independent of all other wiring, except at defined connection points: the supply, signals, ancillary devices, and communication circuits.

In practice: no sharing a raceway with lighting or power circuits. Not "keep them apart where convenient." Independent.

Where a shared pathway is genuinely unavoidable, that is an AHJ conversation before you pull, not after.

Bonding: commonly cited as Rule 32-104

Exposed non-current-carrying metal parts bonded to ground per Section 10, with a bonding conductor incorporated where the system uses non-metallic wiring methods.

The dedicated circuit and the red lock-on: commonly cited as Rule 32-108

This is the requirement everyone knows and the rule number we are least sure about.

The fire alarm panel must be supplied by a separate, dedicated circuit, with a disconnecting means that is:

• Permanently marked
• RED
• Lockable in the ON position

The reasoning is obvious once you have seen the failure. A fire alarm panel sharing a circuit with anything else can be de-energised by someone troubleshooting that other thing. Red marking makes the breaker identifiable at a glance. The lock-on makes killing it a deliberate act rather than a casual one.

On site, the failure modes are predictable: the breaker is on a shared circuit because the panel arrived after the panel schedule was finalised; the lock-on device was never fitted; or it was fitted and later removed during a renovation and nobody put it back. All three are visible on inspection.

Dwelling unit smoke and CO alarms: Rule 32-200 ✅ verified

Confirmed directly from an Alberta Municipal Affairs interpretation bulletin:

• Conductors copper, with ampacity adequate for the circuit, therefore #14 AWG or larger in practice
• Interconnection permitted as an approved Class 2 method in combustible buildings
• Low-voltage control cable must not enter enclosures containing higher-voltage conductors

(Alberta STANDATA 18-CECI-32)

Rule 32-304 (fire pump service boxes) is confirmed from the same bulletin.

One more Canadian requirement worth knowing

Nova Scotia's electrical safety bulletin makes two points that are easy to miss:

1. All fire alarm systems (code-required or voluntary) must be wired per CAN/ULC-S524 and CEC Section 32.
2. Dwelling unit smoke alarms must not be supplied from GFCI- or AFCI-protected circuits.

(Nova Scotia Electrical Safety Bulletin 03-02)

Caveat on that source: the bulletin dates from 2006 and cites S524-01, and directs readers to consult the Chief Electrical Inspector for current guidance. The principle (that voluntary installations are held to the same standard) is consistent with S524's own scope, which explicitly covers both required and voluntary installations.

Which code edition applies in Ontario

The 2024 Ontario Electrical Safety Code (the 29th edition) came into force 1 May 2025. Electrical work performed after that date must meet it. The OESC comprises the Canadian Electrical Code Part I plus Ontario-specific amendments. (Electrical Safety Authority)

Two codes, one installation

A fire alarm install is governed by two separate documents at once, and they cover different things:

You can satisfy one and fail the other. A system wired to perfect S524 architecture, sharing a raceway with the lighting circuit, fails. A beautifully executed dedicated circuit feeding a panel with no fault tolerance across zones fails too.

Two inspectors, two documents, two sign-offs.

Field checklist

• Panel on a dedicated circuit: nothing else on it
• Disconnect permanently marked, red, lockable in the ON position: and the lock-on actually installed
• Conductors copper, 300 V minimum insulation
• Minimum #16 AWG pulled / #19 AWG laid
• Wiring method: enclosed metal raceway, metal-armoured/sheathed cable, rigid non-metallic conduit, or ENT, with the 50 mm masonry embedment rule if ENT in combustible construction
• Fire alarm conductors independent of all other wiring
• Bonding per Section 10
• Dwelling unit smoke alarms not on GFCI or AFCI protection
• Working to the edition in force in your jurisdiction

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