309A Canadian Electrical Code 3 — Questions and Answers
Question 1: Under the CEC, what is the minimum working space required in front of a 600 V panelboard?
- 600 mm
- 750 mm
- 900 mm
- 1000 mm (Correct answer)
Correct answer: 1000 mm
CEC Rule 2-308 requires a minimum clear working space of 1000 mm (1 m) in front of electrical equipment rated up to 750 V to allow safe operation and maintenance.
Question 2: According to the CEC, what colour must the identified conductor (neutral) be in a standard AC power circuit?
- Green
- White or grey (Correct answer)
- Red
- Blue
Correct answer: White or grey
CEC Rule 4-028 requires that the identified (neutral) conductor be white or natural grey in colour throughout its entire length to distinguish it from ungrounded conductors.
Question 3: What is the maximum overcurrent protection permitted for a No. 14 AWG copper conductor according to the CEC?
- 10 A
- 15 A (Correct answer)
- 20 A
- 25 A
Correct answer: 15 A
CEC Table 13 limits the overcurrent protection for No. 14 AWG copper conductors to 15 A maximum, matching the standard residential lighting circuit breaker rating.
Question 4: According to CEC Rule 26-712, how many receptacles are required on a kitchen counter in a dwelling unit that has a continuous counter space of 1800 mm?
- 1 receptacle
- 2 receptacles (Correct answer)
- 3 receptacles
- 4 receptacles
Correct answer: 2 receptacles
CEC Rule 26-712 requires receptacles so that no point along the counter is more than 900 mm from a receptacle. For an 1800 mm counter, a minimum of 2 receptacles are required.
Question 5: What is the CEC requirement for tamper-resistant receptacles in dwelling units?
- Required only in children's bedrooms
- Required only below 450 mm from the floor
- Required for all 15 A and 20 A receptacles (Correct answer)
- Not required in any location
Correct answer: Required for all 15 A and 20 A receptacles
The CEC requires tamper-resistant receptacles for all 15 A and 20 A, 125 V receptacles in dwelling units to protect children from inserting objects into receptacle slots.
Question 6: According to the CEC, what is the maximum distance between supports for 3/4-inch EMT (electrical metallic tubing)?
- 1.0 m
- 1.2 m
- 1.5 m (Correct answer)
- 1.8 m
Correct answer: 1.5 m
CEC Table 12-22 specifies a maximum support spacing of 1.5 m for EMT sized 3/4 inch and smaller, ensuring the tubing remains securely fastened and does not sag.
309A Canadian Electrical Code 3
Under the CEC, what is the minimum working space required in front of a 600 V panelboard?