

Ships same day if ordered by 12 pm
Manufacturer pricing rules prevent us from advertising our discount — no account or email required to see it.
Secure Payments
Easy Returns
Expert Advice
Fast Shipping
The THHNCU-GENERIC thhn400mcmstrblkmr is a 400 kcmil stranded copper THHN building wire with black PVC insulation and a nylon jacket, rated for 600 volts and 90 degrees C in dry conditions. This cut-to-length wire is a heavy-gauge conductor used in commercial and industrial electrical installations where high ampacity and thermal performance are required. Licensed electricians select this wire for feeder runs, panel feeds, and service entrance applications governed by the National Electrical Code. The 37-strand construction provides flexibility for pulling through conduit on demanding installations.
This wire is suited for use in commercial, industrial, and large residential electrical systems where 400 kcmil feeder-grade conductors are specified. It is typically pulled through conduit as part of main service feeds, subpanel feeders, or large motor branch circuits. The cut-to-length format allows jobsite procurement of exact footage, reducing waste on custom-length pulls. Installers working under NEC Article 310 ampacity tables will find the rated capacities of 280 amps at 60 degrees C, 335 amps at 75 degrees C, and 380 amps at 90 degrees C directly applicable to conductor sizing calculations.
Designed for use in conduit systems requiring THHN-rated 400 kcmil copper feeder conductors in compliance with NEC ampacity and installation requirements for 600-volt circuits.
Installation of 400 kcmil feeder conductors is performed by licensed electricians in accordance with the National Electrical Code and applicable local codes. De-energize all circuits and verify absence of voltage before terminating conductors at panels, disconnects, or lugs. Wire pulling lubricant rated for PVC insulation is recommended for long conduit runs to prevent jacket damage. Termination hardware must be rated and listed for use with 400 kcmil copper conductors at the applicable temperature rating.
Thanks for subscribing!
This email has been registered!