Product Information

Specification

400 MCM THHN THWN-2 Stranded Copper Building Wire

Allowable Ampacity:

• 285 Amps for General Applications (60°C)

• 335 Amps in Wet Locations (75°C)

• 380 Amps in Dry Locations (90°C)

Description

400 MCM THHN/THWN-2 stranded copper wire is designed for high-capacity electrical installations in residential, commercial, and industrial settings. Its dual rating for THHN (thermoplastic high heat-resistant nylon, dry) and THWN-2 (wet) environments ensures reliable performance in diverse conditions. Rated at 600 volts, it operates at temperatures of up to 90°C. Its flame-retardant PVC jacket resists sunlight, moisture, and chemicals, making it suitable for demanding applications.

Applications for 400 MCM THHN Wire

400 MCM THHN wire, with a capacity of up to 380 amps, is ideal for:

• Large Commercial Services: Supporting shopping malls, high-rise buildings, and large institutional structures.

• Major Industrial Feeders: Distributing power in large industrial facilities or complexes.

• Institutional Buildings: Powering hospitals, university buildings, or similar large-scale operations with substantial electrical loads.

• Service Entrances: Suitable for delivering power to significant structures when appropriately configured.

• Conduit Installations: Designed for smooth pulls through conduits in structured wiring systems.

Also Known As

400 MCM THHN wire, 400 stranded THHN wire, 400 gauge stranded wire, 400 copper wire, 400 MCM stranded copper wire, 400 MCM conduit wire, 400 MCM nylon wire, 400 MCM THHN/THWN-2 wire, 400 MCM thermoplastic-insulated copper wire, 400 KCMIL copper wire.

Construction of 400 MCM THHN Stranded Wire

• Conductor:
  Flexible annealed soft copper per ASTM B3 and ASTM B8.

• Insulation:
  Flame-retardant PVC jacket that resists sunlight, moisture, and chemicals.

• Outer Jacket:
  Abrasion-resistant nylon coating for smooth installation in conduits.

Standards for 400 MCM THHN/THWN-2 Wire

• ICEA S-73-532

• UL 1277 (Resistant to flame, moisture, and sunlight)

• UL 1581, UL 83, UL 1063, UL 758

• ASTM B3 and B8 conductor standards

• ANSI/NFPA 70 for Safe Electrical Design and Installation

• RoHS compliant

• Approved for NEC Class I and II systems and Division 2 hazardous locations

• Allowed for Exposed Run (ER) and complies with NEC regulations

• Complies with A-A59544 specifications for durability and safety

Specifications of 400 MCM THHN Wire

• Size (MCM): 400

• Weight per 1,000 ft: 1,354 lbs

• Outside Diameter: 0.88 inches

• Conductors: Annealed Soft Copper per ASTM B3 and ASTM B8

• Number of Strands: 37

• Insulation: PVC

• Insulation Thickness (mils): 60

• Nylon Thickness (mils): 8

• Jacket: PVC

*Data provided on this page is subject to change based on different manufacturers' variances

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