309A Wiring Methods and Materials 6

Question 1

What type of conduit is required for a concrete-encased underground duct bank?

Accepted Answer

PVC Schedule 40 or rigid metal conduit

Answer

Concrete-encased duct banks typically use PVC Schedule 40 conduit for its corrosion resistance and smooth interior, or rigid metal conduit where additional mechanical protection is needed.

Question 2

What is the CEC requirement for identifying conductors that have been re-identified from their original colour?

Accepted Answer

Apply tape or markers at each end and at every accessible point

Answer

When re-identifying conductors (such as marking a white conductor as a switch leg), the CEC requires identification at each end and at every point where the conductor is accessible.

Question 3

What is the minimum bending radius for NMD90 cable?

Accepted Answer

5 times the cable diameter

Answer

The CEC requires a minimum bending radius of 5 times the overall diameter of NMD90 cable to prevent damage to the conductors and insulation during installation.

Question 4

According to the CEC, what is the maximum height above finished floor for a receptacle outlet in a dwelling unit without being considered out of reach?

Accepted Answer

1700 mm

Answer

Receptacles mounted above 1700 mm are generally considered out of reach for standard accessibility. The CEC and building codes set this as a practical limit for general-purpose outlets.

Question 5

What material is the armour of AC90 cable typically made from?

Accepted Answer

Aluminium

Answer

AC90 cable armour is typically made from interlocking aluminium strips, which provide mechanical protection while being lighter and more corrosion-resistant than steel armour.

Red Seal Electrician 309A Practice Test

Red Seal Electrician 309A Practice Test

309A Wiring Methods and Materials 6