An electrician is installing armoured cable (AC90) in a ceiling plenum space above a suspended ceiling where environmental air is handled. According to the Canadian Electrical Code (CEC), what specific precaution must be taken regarding the termination of the armoured cable?

Question: An electrician is installing armoured cable (AC90) in a ceiling plenum space above a suspended ceiling where environmental air is handled. According to the Canadian Electrical Code (CEC), what specific precaution must be taken regarding the termination of the armoured cable?

Answer options:

• The armoured cable must be run in rigid conduit for its entire length. ✅ An insulating bushing (anti-short bushing) is required at all armoured cable terminations.
• The armoured cable requires a continuous bond wire connecting all fixture boxes.
• The cable must be supported every 500 mm (20 in.) in the plenum.

Correct answer: An insulating bushing (anti-short bushing) is required at all armoured cable terminations.

Explanation: Rule 12-610(5) and 12-902(1) in the CEC requires an insulating bushing (commonly called an anti-short bushing) to be installed between the conductors and the armour at all terminations of armoured cable to protect the conductors from abrasion. While support and bonding are generally important, the specific precaution for terminations is the bushing.