Building Wire

Mid America Wire & Cable stocks a comprehensive selection of building wire for commercial, industrial, and residential electrical installations. From THHN/THWN-2 single conductors to USE-2 service entrance cable, our building wire products meet NEC requirements and carry UL listings. Available in copper and aluminum conductors across a full range of AWG and MCM sizes, with solid and stranded options.

9 product lines Ships nationwide UL / Mil-spec options

THHN

Thhn

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Metal Clad

AIA W/ PVC Jacket

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Aluminum Interlocked Armored (aia)

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Romex

Type Nm-b

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Type Nmd90

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Type SER

Aluminum Service Entrance

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Copper Service Entrance

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RHH/RHW-2/USE-2

Aluminum Rhh/rhw-2/use-2

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Copper Rhh/rhw-2/use-2

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About Building Wire

Building wire is the backbone of every electrical installation, powering everything from branch circuits and lighting to feeders and service entrances. Mid America Wire & Cable stocks THHN and THWN-2 dual-rated single conductors in copper and aluminum from 14 AWG through 1000 MCM, in solid and stranded constructions, and in all standard NEC colors. THHN/THWN-2 is dual-rated for dry (90°C) and wet (75°C) locations and is the most widely specified single-conductor building wire in North America. For service entrance applications, we carry USE-2 (Underground Service Entrance) and RHH/RHW-2 cable. All building wire is UL-listed and manufactured to meet or exceed UL 83, UL 854, and NEC Article 310 requirements.

Free sizing tools: Wire Size & Voltage Drop Calculator AWG Wire Gauge Chart

Building Wire: Frequently Asked Questions

Nearly all modern building wire is manufactured as dual-rated THHN/THWN-2. THHN is rated 90°C in dry locations; THWN-2 is rated 90°C in wet or dry locations. The same physical wire carries both ratings, so THHN/THWN-2 can be used in any NEC-compliant dry, damp, or wet location.

The NEC requires specific colors only for grounded (neutral) and grounding conductors: white or gray for neutral, green or green/yellow for ground. Ungrounded (hot) conductors can be any color other than white, gray, or green, but common conventions are black, red, blue, and yellow for 120/208/240V systems, and brown, orange, yellow for 277/480V systems.

Yes. We stock aluminum THHN/THWN-2 and XHHW-2 in 6 AWG through 1000 MCM for large feeders, service entrances, and cost-sensitive applications where aluminum's lighter weight and lower cost are desired.

USE-2 (Underground Service Entrance) is a cross-linked polyethylene (XLPE) insulated cable rated for direct burial and wet locations at 90°C. It's commonly used for service entrance feeders from utility transformers to meter bases, and for underground feeders to detached buildings, subpanels, and irrigation equipment.