12/4 Stranded Copper MC Cable W/ Ground

12/4 Stranded Copper MC Cable W/ Ground is a heavy-duty 600V Metal-Clad (MC) building wire engineered for 3-phase 4-wire power distribution, 277V/480V commercial lighting circuits, and multi-circuit home runs in commercial, industrial, institutional, and multi-residential applications. Constructed with four flexible 12 AWG Class B stranded bare copper conductors, an insulated 12 AWG green ground wire, THHN/THWN-2 insulation, protective binder tape, and an overall aluminum interlocked armor, it delivers exceptional crush resistance while eliminating the high labor costs of pulling wire through conduit.

Key Features & Benefits

• Labor-Saving Metal-Clad Design: Pre-armored assembly eliminates the time-consuming process of pulling individual conductors through conduit, lowering jobsite labor costs and accelerating project timelines.

• 3-Phase / 4-Conductor Power Distribution: Four circuit conductors enable 3-phase 4-wire wye circuit layouts, dual 120V/208V branch runs with separate neutrals, or 277V/480V commercial lighting circuits.

• High-Flex Stranded Copper: Built with Class B stranded bare copper conductors to provide superior flexibility, easier pulls, and smooth terminations inside junction boxes and panel boards.

• Dual-Rated THHN/THWN-2 Insulation: High-dielectric PVC insulation with a clear nylon outer skin provides superior heat, flame, moisture, and gasoline/oil resistance rated for 90°C dry applications.

• Lightweight Aluminum Interlocked Armor: Tough interlocked aluminum armor (AIA) shields internal conductors from physical damage, crushing, and abrasion while maintaining maximum bendability.

• Integrated Green Ground Conductor: Includes a dedicated 12 AWG green THHN/THWN-2 insulated stranded copper ground conductor for complete circuit safety.

Technical Specifications

Engineering Overview 

• Application: 3-phase branch, feeder, and distribution circuits in commercial, industrial, institutional, and multi-residential power, lighting, control, and signal systems.

• Voltage Rating: 600 Volts.

• Ampacity: 30 Amps @ 90°C (Based on 30°C ambient temperature per NEC Table 310.16; refer to NEC 240.4(D) for overcurrent protection limits; apply derating factors per NEC 310.15(C)(1) when more than three conductors carry current).

• Conductor Material: Class B stranded soft-drawn bare copper (4 conductors, 12 AWG).

• Insulation: PVC (0.015" thickness) with clear Nylon jacket (0.004" thickness) (THHN/THWN-2).

• Grounding Conductor: One 12 AWG green THHN/THWN-2 insulated stranded copper conductor.

• Phase Identification: White, Black, Red, Blue phase conductors (120V/208V system color code).

• Armor: Overall lightweight aluminum interlocked armor.

• Diameter over Armor: 0.58 inches (14.73 mm).

• Approximate Net Weight: 192 lbs / 1,000 ft.

• Temperature Rating: -40°C to +90°C Dry.

• Approvals & Compliance: UL Listed (UL 83, UL 1569, UL 1581), IEEE 1202 Vertical Tray Flame Test (70,000 BTU/hr), ASTM B3 & B8, Federal Spec A-A-59544, NEC Articles 230.43, 300.22, 330, 518.4, 520.5, 530, 545.4, 645. Hazardous Locations: Class I Div. 2, Class II Div. 2, Class III Div. 1 & 2.

** All values are nominal and subject to correction 

• 3-Phase 4-Wire Power & Lighting: Ideal for running 120V/208V 3-phase wye power or 277V/480V high-bay commercial lighting circuits with a shared neutral in industrial facilities and retail stores.
• Multi-Circuit Home Runs: Allows electricians to pull two independent 120V branch circuits with dedicated neutrals back to the panel in a single armor run.
• Exposed & Concealed Wiring: Approved for exposed runs mounted to building structural members or concealed runs installed above dropped ceilings and inside drywall stud cavities.
• Places of Assembly: Fully compliant with NEC rules for places of assembly accommodating 100 or more people, including auditoriums, theaters, studios, and commercial facilities.
• Environmental Air Spaces (Plenums): Safe for installation in environmental air-handling spaces and plenums per NEC Article 300.22.
• Approved Cable Trays & Raceways: Ideal for distribution routing in approved industrial cable trays, open ladder racks, and wireways without requiring rigid metal conduit.

Real-world application examples are provided for educational and general planning purposes only. Project requirements vary based on system design, environmental factors, and local codes. Buyers and specifiers are responsible for verifying that all materials meet exact job specifications and comply with NEC and local electrical regulations. Always consult with a licensed electrician prior to installation.

General Shipping Information

In-stock orders placed before 3pm EST typically ship within 1-2 business days. Our business days are Monday through Friday; we do not process orders on Saturday, Sunday, or major US Holidays.

You will receive an e-mail with a tracking number within 1-2 business days from the time its shipped. You will also be able to view your order status and tracking numbers in your account order history.

Expedited Shipping

Expedited shipments are delivered Monday-Friday except on US Holidays. The order must be placed before 12pm CST to ship same day ( Mon-Fri Only).

Returns

You have 30 days from the day you receive the item to contact us for a return. Returns are subject to a 30% Restocking Fee.

Please contact us at help@wireamerica.com to request a return authorization. Have your order number or name the order was placed with ready and we will email you an RMA (return) number and instructions for return. Currently, we do not offer exchanges. A new order must be placed if you need a different item. If you provide the new order number at the time of your return request, the restocking fee may be lowered.

Orders on any items with a material value of $50 or less are non-returnable.