SPEC400 kcmil at a glance
| Also called | 400 MCM |
|---|---|
| Conductor area | 400 kcmil · 203 mm² |
| Stranded (Class B) | 37 strands · 0.728 in |
| THHN outside diameter | ≈ 0.864 in |
| Finished copper wire weight | ≈ 1,357 lb / 1,000 ft |
| Bare copper weight | ≈ 1,236 lb / 1,000 ft |
| Common put-ups | 1,000 ft reels |
| Conductor | 60 °C | 75 °C | 90 °C |
|---|---|---|---|
| Copper | 280 A | 335 A | 380 A |
| Aluminum | 225 A | 270 A | 305 A |
Dimensions from NEC Chapter 9 Tables 5 and 8. Weights are approximate and vary by manufacturer and insulation. For design, follow the NEC and a licensed electrician.
Wire types we buy in 400 kcmil
01Identify 400 kcmil Wire by Its Markings
Start with the reel tag and jacket print. Look for the conductor size, copper or aluminum identification, insulation designation, manufacturer and date code. Photograph the complete tag and a readable section of jacket print rather than relying on a handwritten inventory label. If you want to sell 400 MCM wire, that older designation means the same conductor area as 400 kcmil.
This size uses kcmil naming, not an aught designation. Our wire gauge chart explains the distinction between AWG and kcmil sizes. Keep separately marked reels and cut lengths identified so we can review each material accurately.
For the supplied Class B construction, the conductor has 37 strands and measures 0.728 inches in diameter. Approximate THHN outside diameter is 0.864 inches, including insulation. Diameter helps check an identification, but it does not replace readable markings: insulation thickness and construction can affect the finished diameter. Include photos of exposed conductor ends when available without damaging usable material.
02Understand the Specs Before Comparing Inventory
The 400 kcmil designation describes conductor area, equivalent to 203 mm². It does not, by itself, establish the wire's insulation type, permitted installation or usable circuit capacity. Copper and aluminum conductors of the same area also have different weights and ampacity values.
Under NEC 310.16 at 30°C ambient, before adjustments, the supplied copper ampacities are 280 amps at 60°C, 335 amps at 75°C and 380 amps at 90°C. The corresponding aluminum values are 225, 270 and 305 amps. Our wire ampacity chart provides context for reading the temperature columns.
Do not select a circuit rating from the highest column alone. Terminal temperature ratings, installation conditions, applicable adjustment and correction factors, and other NEC requirements control the final selection. A licensed electrician or engineer should confirm suitability for any proposed installation. For selling surplus, the useful information is what the material actually is: metal, size, insulation designation, quantity and condition. Those details let us compare inventory without treating every 400 kcmil reel as interchangeable.
03Common Uses in Houston Construction and Plants
Surplus 400 kcmil cable can come from commercial feeder work, large service installations and industrial motor feeder projects around Greater Houston. Material left after a project change may still be reusable when its markings remain readable and its insulation and conductor are sound. Keep those leftovers separate from demolition scrap.
Copper 400 kcmil appears in some 400-amp residential service applications, but that is not a blanket ampacity rating. Applicable dwelling-service provisions and the actual installation must support the selection. Commercial feeder applications may use the supplied 335-amp copper value at 75°C, subject to the installation requirements. Parallel sets in larger services require their own design review.
For sellers in Harris, Fort Bend, Montgomery, Brazoria, Galveston, Chambers and Waller counties, identify whether your inventory consists of individual conductors or matched project leftovers. If material was purchased for a parallel installation, tell us what lengths and markings remain together. That helps us evaluate the inventory; it does not certify the material for another project.
04400 kcmil Wire Types We Buy
We review reusable 400 kcmil THHN/THWN-2 wire and XHHW-2 wire in copper and aluminum. Send the actual insulation marking rather than describing everything as building wire. Where a conductor carries a dual designation, include a photo showing the full print so we can identify it correctly.
As 400 kcmil wire buyers, we consider full reels, partial reels, coils and usable cut lengths. New, unused material is welcome, and previously handled surplus may also be reusable if its condition supports resale. Show the reel sides, outer wraps, conductor ends and any visible damage in your photos.
Short scrap pieces, burned insulation, severely cut jackets or heavily damaged conductor may be better suited to scrap than reuse. We will tell you what appears reusable rather than treating damaged material as sound inventory. Avoid stripping intact insulation before review: the marked jacket helps establish the wire type, and removing it can eliminate the material's reuse potential.
05How Footage, Weight and Packaging Affect Value
400 kcmil copper wire value depends on more than the copper market. We also consider wire type and demand, footage, size, manufacturer and date code, quantity, packaging condition and pickup logistics. Reusable wire is usually worth more than its scrap or melt value, but its condition and identification must support reuse.
A common put-up is a 1,000-foot reel. Finished copper THHN/THWN-2 weighs approximately 1,357 pounds per 1,000 feet. For a simple estimate, 1,357 pounds of net finished wire divided by 1,357 pounds per 1,000 feet indicates approximately 1,000 feet. Subtract reel and packaging weight first; gross scale weight is not wire weight.
Bare stranded copper weighs about 1,236 pounds per 1,000 feet, while bare aluminum weighs about 376 pounds per 1,000 feet. Those figures are not substitutes for finished insulated-wire weights. Use our copper wire weight chart as a reference, and report whether footage comes from a tag, measurement or weight estimate. Keep readable tags attached and protect remaining wire from additional handling damage.
06Sell 400 kcmil Wire in Houston: Pickup and Review
Text photos to 951-403-5738 or email industrial832@gmail.com with the footage or weight and your Greater Houston location. Include reel tags, jacket print, overall condition and the number of separate reels or lengths. We review the information and provide a written offer before arranging the next step. See how the selling process works for the sequence.
Pickup is scheduled at your site. Heavy reels require planning, so describe site access, where the material sits and what handling equipment is available. Do not assume a loaded reel can be moved by hand. Discuss access and loading conditions before the scheduled visit; our Houston wire pickup information explains the local service.
Drop-off is by appointment only at 6402 McGrew St, Houston, TX 77087, in southeast Houston's Mayfair area near I-45 and I-610. Call first before transporting material. We verify the wire on site, then payment follows the written offer. Houston Wire Buyers serves Greater Houston only and is not affiliated with Houston Wire & Cable Company or any manufacturer.
FAQQuestions sellers ask
Can I sell mixed copper and aluminum 400 kcmil inventory?
Yes. We buy reusable 400 kcmil material in both metals. Identify each reel or bundle separately in your submission and include its markings, quantity and condition. Do not use copper weight figures to estimate aluminum footage. Separate inventory details help us review each material on its own merits.
What if the reel tag and jacket print do not agree?
Send clear photos of both and flag the discrepancy before scheduling transportation. A reel may have been reused, so its tag alone may not identify the wire currently on it. We need to review the material's actual markings and verify it on site rather than assume the tag is correct.
Can you quote my wire if I only know its weight?
Send the weight along with photos and state whether it includes the reel or packaging. Weight alone does not establish metal, insulation type, footage or reusable condition. We review the available information for a written offer, and the material is verified on site before payment under that offer.
Should I unwind a partial reel to prove its length?
You do not need to unwind it just to make an initial inquiry. Send the remaining footage estimate and explain its source, such as inventory records or a net-weight calculation. Keep the wire secured and its markings accessible. Unnecessary handling can damage insulation or make a heavy reel harder to transport.
Will an old manufacturer date code rule out a sale?
A date code is one factor in our review, not enough by itself to determine value or reuse potential. Send it with the manufacturer name, insulation markings and condition photos. Storage history and visible damage also matter. We evaluate the actual inventory rather than promise acceptance based on age alone.