Wiring Methods and Materials Flashcards

What is the main advantage of using ACWU90 cable over AC90 in outdoor or wet applications?

Answer: A moisture-resistant outer jacket

ACWU90 cable includes a moisture-resistant PVC outer jacket over the armour, making it suitable for wet locations and direct burial, unlike AC90 which is rated for dry locations only.

What is the CEC requirement for wire connectors (marrettes/wire nuts) used to splice conductors?

Answer: They must be CSA-approved for the conductor sizes being joined

The CEC requires all wire connectors to be CSA-approved and listed for the specific conductor sizes and number of conductors being joined to ensure safe, reliable connections.

When installing cables through wood framing members, what is the minimum distance the cable must be from the edge of the stud?

Answer: 32 mm (1-1/4")

CEC Rule 12-516 requires cables to be at least 32 mm (1-1/4") from the nearest edge of a wood framing member, or be protected by a steel plate, to prevent nail or screw damage.

What is the purpose of a cable tray system in a commercial or industrial installation?

Answer: To support and route cables in an open, accessible manner

Cable tray systems provide an open, accessible method of supporting and routing power, control, and communication cables in commercial and industrial buildings, allowing easy maintenance and additions.

According to the CEC, what type of conduit fitting is required when transitioning from EMT to a device box?

Answer: A compression or set-screw connector

EMT connections to boxes require either compression-type or set-screw-type connectors approved for the purpose. These fittings secure the EMT to the box and maintain system integrity.

What is the maximum ambient temperature rating for standard NMD90 cable insulation?

Answer: 90°C

NMD90 cable insulation is rated for a maximum temperature of 90°C, as indicated by the '90' in its designation. However, ampacity is typically limited to 60°C terminal ratings.