Canada Tightens Electrical Safety Rules for Armored Cables Conduits

In electrical engineering, armored cables and metal conduits serve as critical components for ensuring the safe operation of power systems. Understanding proper selection and installation methods is essential for compliance with the Canadian Electrical Code (CEC) and avoiding potential safety hazards.

The Canadian Electrical Code (CEC) 2012 Part I Section 12-600 defines armored cable as "a fabricated assembly of insulated conductors in a flexible metallic enclosure." AC90 armored cable has gained widespread application in electrical engineering due to its excellent mechanical protection and installation flexibility.

• Conductor materials: Copper, aluminum, or copper-clad aluminum
• Conductor sizes:
  • Copper: 14 AWG to 1 AWG
  • Aluminum or copper-clad aluminum: 12 AWG to 1 AWG
• Voltage rating: All armored cables are rated for 600 volts or less

Armored cable is suitable for both exposed and concealed installations, with important restrictions:

• Avoid locations subject to physical damage
• Not permitted in corrosive environments
• Direct burial is prohibited

• Secure with straps or staples without damaging conductors
• Special precautions required when passing through wooden structural members

CEC Section 12-610 specifies crucial requirements for armored cable termination:

• Conductors emerging from armor require protection against abrasion
• For 8 AWG or larger conductors:
  • Insulated bushings required unless equipment provides smooth-edged hubs
  • Alternatively, securely fastened insulating material may separate conductors from fittings
• Termination design must allow visual inspection of bushings
• Open wiring connections require junction boxes or fittings with individual bushing holes

• UL 4, ANSI C33.9: Armored cable safety standards
• UL 514 A and 514B: Junction box and fitting standards
• W-F-406: Federal specification for electrical cable and conduit fittings
• NEMA FB-1: Cast metal boxes and conduit body fittings
• CEC Section 12-600: Wiring methods (armored cable)
• CSA C22.2 No. 51: Armored cable safety standard
• CSA C22.2 No. 18.1 and 18.3: Junction box and fitting standards

Metal flexible conduit provides adaptable connections with strict usage limitations:

• Permitted in dry locations for exposed or concealed work
• In damp locations, conductors must be lead-covered or approved type
• Prohibited applications:
  • Underground or embedded in concrete/aggregate
  • With rubber-insulated conductors exposed to oil/gasoline
  • Elevators, battery rooms, or hazardous locations (with few exceptions)
• Limited to 600V systems

Conduits ≤6 feet may serve as grounding conductors when approved (note: currently no UL or CSA-approved flexible conduits for this purpose). Special rules apply for hazardous locations.

• Materials: Steel or aluminum (5/16" to 4" sizes)
• Minimum size: ½" generally required
• Bend limits: Maximum four 90° bends in concealed work (CEC Rule 12-940)

• UL 1, ANSI C33.92: Flexible metal conduit standards
• UL 514: Junction box and fitting standards
• W-F-406/WW-C-566: Federal specifications
• NEMA FB1: Conduit and cable accessories
• CEC 12-1000: Wiring methods (conduit)
• CSA C22.2 No. 56: Flexible metal conduit standards

Proper fittings are essential for safe armored cable and conduit installations:

• Must meet UL/CSA standards for respective cable/conduit types
• Require approved fittings for termination
• Bushings must separate conductors from armor
• Grounding-type fittings required when armor serves as ground path

• Secure mechanical attachment without cable damage
• Vibration-resistant connections
• Insulated throats for conductor protection
• Locking nuts that resist loosening
• Simplified installation designs
• Robust steel or malleable iron construction
• Hazardous location compliance where applicable

• 90° angle fittings: Single-screw designs with inspection ports
• Compression fittings: Malleable iron or steel construction
• Dual-screw fittings: With rounded bushing surfaces
• Short-circuit bushings: Protect conductors from sharp edges

Proper selection and installation of armored cables, metal conduits, and compliant fittings remain fundamental to electrical system safety and reliability. This guide summarizes key CEC requirements and industry standards to support informed decision-making by electrical professionals.