What Size Wire for 200 Amps in Canada? (CEC)

Quick answer: wire size for a 200 A breaker in Canada

Minimum conductor for 200 A, not more than three conductors in a raceway or cable, 30 °C ambient.

Rule 4-006 limits the conductor to the termination temperature of the equipment. Unmarked equipment rated more than 100 A is treated as 75 °C, and 200 A panels, meter bases and breakers are normally marked 75 °C, so the 60 °C rows are rare at this size. A 90 °C conductor does not let you go smaller: 2/0 copper is 195 A at 90 °C but only 175 A at 75 °C, and 4/0 aluminum is 205 A at 90 °C but 180 A at 75 °C. The 90 °C value is the starting point for Table 5A and 5C correction factors.

200 amp service: national code vs Ontario Table 39

Table 39 used to give smaller sizes for single-dwelling services across Canada. It was deleted from CSA C22.1 in the 2021 edition. Ontario added it back as Rule 4-004 26) in its amendments (kept in the November 2024 Ontario amendments to CSA C22.1:24), so the answer for a house service depends on the province.

Ontario's Table 39 (Ontario amendments, November 2024):

Conditions: 3-wire 120/240 V or 120/208 V only, conductors with a 90 °C insulation rating, and the calculated or demonstrated load (Rules 8-104 and 8-106) must not exceed the 75 °C ampacity of the conductor. Loads calculated under Section 8 may exceed the table's maximum load by 5%. The max load column is the 75 °C ampacity, which is why it is lower than the breaker. British Columbia's regulator (Technical Safety BC bulletin IB-EL 2016-07, revised March 2025) works its 180 A example with Table 2 and lands on 3/0 copper. Quebec uses its own edition of the code; check with the authority having jurisdiction.

Wire size for 200 amps by distance (metres, 240 V)

Smallest size that keeps a 120/240 V single-phase run at or under the Rule 8-102 3% limit. The 160 A columns use the Rule 8-102 default for an unknown load (80% of a 200 A breaker); the 200 A columns are for a known full load. Ampacity sets the floor, so the table never goes below 3/0 copper or 250 kcmil aluminum.

Example: a 200 A subpanel in a shop 100 m from the house, load not yet known. Rule 8-102 says to use 160 A. 3/0 copper reaches only 89 m, so it falls short; 4/0 copper (112 m) is the first size that works. In aluminum, 300 kcmil reaches 97 m and 350 kcmil (113 m) is needed. Upsizing also changes the bonding conductor when the new ampacity passes 200 A (see below), and the 5% total limit still includes the service conductors and the branch circuits after the subpanel.

Maximum length at 200 amps by wire size

The longest one-way run, in metres, before each size reaches the drop shown. Three-phase columns use the √3 formula. These are resistance-only figures; large conductors in steel raceway at a low power factor see somewhat more drop from reactance.

Copper

Aluminum

For your exact load and length, use the Canadian voltage drop calculator or the Canadian wire size calculator, which checks ampacity and Rule 8-102 together.

Bonding, grounding and neutral conductors for 200 amps

• Bonding conductor (Table 16): 6 AWG copper or 4 AWG aluminum for an overcurrent device or conductor ampacity up to 200 A.
• Upsized for voltage drop: Table 16 is entered with the ampacity of the largest ungrounded conductor, so upsizing 3/0 copper to 4/0 (230 A) or larger raises the bonding conductor to 4 AWG copper. The table below shows the common upsizes.
• Grounding conductor to the electrode (Rule 10-114): not smaller than 6 AWG copper or 4 AWG aluminum.
• Service neutral: sized from Table 16 on the ampacity of the ungrounded conductors, and large enough for the calculated unbalanced load and the equipment lugs. ESA Bulletin 4-3-11 gives the Ontario 200 A examples: 2/0 or 3/0 copper → 6 AWG Cu or 4 AWG Al neutral; 4/0 aluminum → 4 AWG Al or 6 AWG Cu; 250 kcmil aluminum → 2 AWG Al or 4 AWG Cu.

How much load can a 200 amp service carry?

The figures assume a balanced load and unity power factor. A 200 A service at 240 V is 48 kW. Rule 8-200 calculates a dwelling at 5,000 W for the first 90 m² of living area and 1,000 W for each extra 90 m², plus space heating, air conditioning, the range, tankless water heaters, EV charging and other loads at their demand factors; homes with electric heat or two EV chargers are the usual reason to go to 200 A. Continuous loads on breakers not marked for 100% continuous operation are generally limited to 80% of the rating under Rule 8-104. The amps to watts calculator handles power factor.

CEC vs NEC for 200 amps

The raw ampacities in CEC Tables 2 and 4 match NEC Table 310.16 for these sizes, so the feeder answer (3/0 copper, 250 kcmil aluminum) is the same in both countries. For a house service, the US uses NEC 310.12 (83% of the service rating, so 2/0 Cu or 4/0 Al at 200 A), which gives the same sizes as Ontario's Table 39 but not the national CEC. Other differences: voltage drop is mandatory under Rule 8-102, distances are in metres, and bonding comes from Table 16 instead of NEC Table 250.122 (both give 6 AWG Cu / 4 AWG Al at 200 A). For the US version, see wire size for 200 amps (NEC). For smaller Canadian services and feeders, see 100 amps, 60 amps and 50 amps.

Sources

• Electrical Safety Authority, Ontario Amendments to CSA C22.1 (November 2024) (Rule 4-004 26), Table 39)
• Electrical Safety Authority, Proposal 2021-OA-002 (Table 39 deleted from the national code, kept in Ontario)
• Electrical Safety Authority, Bulletin 4-3-11, Sizing of neutral conductors
• Technical Safety BC, IB-EL 2016-07, Determining minimum service or feeder conductor size for single dwellings (Revision 2, March 2025)
• VRI Electrical, Cable Ampacity Tables – CEC / CSA C22.1 (Tables 2 and 4)
• Electrical Industry News Week, Guide to the CE Code, Section 8 (Rules 8-102, 8-200)
• SparkShift, CEC Rule 10-114 and Table 16
• Conductor resistance: NEC Chapter 9 Table 8 values at 75 °C, converted to metres