Description

Technical Parameters

Certification

Copper THHN/THWN-2 Wire for power distribution

PRODUCT REAL SHOT

THHN/THWN-2 copper building wire for power distribution

Copper THHN/THWN-2 Wire for factory wiring

THHN/THWN-2 copper building wire for factory wiring

350 Kcmil UL 83 Copper THHN/THWN-2 Wire PVC Insulated Thermoplastic Building Wire

UL Listed 350 kcmil THHN Wire PVC Insulation Copper Building Wire for Heavy-Duty Distribution

This 350 kcmil UL 83 Copper THHN/THWN-2 Wire is a heavy-gauge PVC insulated copper wire built to UL 83 standards, designed for high-amperage power distribution in large-scale commercial and industrial facilities. Constructed with a high-purity annealed copper conductor and a robust dual-layer thermoplastic system - PVC insulation core reinforced by a protective nylon outer jacket - it holds dual THHN (dry location, 90°C) and THWN-2 (wet location, 90°C) ratings. As a high-capacity PVC insulation THHN/THWN-2 copper wire, it is the go-to specification for main service feeds and heavy-load feeder circuits that demand reliable, code-compliant performance.

PRODUCT SPECIFICATIONS

Copper THHN/THWN-2 Wire for warehouse wiring

Conductor Size	Conductor Stranding	Insulation Thickness	Jacket Thickness	Nominal O.D.	Approx Net Weight	Allowable Ampacities(1) @30℃ Ambient
AWG/ Kcmil	Number of Strands	mils	mils	Inch	lbs/1000ft.	75℃	90℃
14	1	15	4	0.101	17	20	25
12	1	15	4	0.119	25	25	30
10	1	20	4	0.150	39	35	40
14	19	15	4	0.113	16	20	25
12	19	15	4	0.133	25	25	30
10	19	20	4	0.164	39	35	40
8	19	30	5	0.218	63	50	55
6	19	30	5	0.252	96	65	75
4	19	40	6	0.325	153	85	95
3	19	40	6	0.353	193	100	115
2	19	40	6	0.381	236	115	130
1	19	50	7	0.437	300	130	145
1/0	19	50	7	0.480	373	150	170
2/0	19	50	7	0.522	464	170	195
3/0	19	50	7	0.572	577	200	225
4/0	19	50	7	0.629	719	230	260
250	37	60	8	0.703	857	255	290
300	37	60	8	0.758	1019	285	320
350	37	60	8	0.808	1181	310	350
400	37	60	8	0.851	1342	335	380
500	37	60	8	0.937	1665	380	430
600	61	70	9	1.036	2002	420	475
750	61	70	9	1.134	2465	475	535
1000	61	70	9	1.273	3296	545	615

CERTIFICATIONS

THHN/THWN-2 copper building wire for warehouse wiring

PACKAGING

Copper THHN/THWN-2 Wire for data center electrical wiring

Plastic Reel

THHN/THWN-2 copper building wire for data center electrical wiring

Small Wooden Reel

Copper THHN/THWN-2 Wire for solar conduit wiring

Large Wooden Reel

APPLICATION

THHN/THWN-2 copper building wire for solar conduit wiring

Cable Tray Raceway Systems

dry location rated Copper THHN/THWN-2 Wire

Underground Conduit Installation

Branch Circuit Wiring

CASE

wet location rated Copper THHN/THWN-2 Wire

Mayo Clinic Hospital, Saint Marys Campus

30 Hudson Yards

low friction jacket Copper THHN/THWN-2 Wire

Stanford University California USA

WHY CHOOSE US

30Years of experience
in one-stop service

Dongguan Greater Wire & Cable Co., Ltd. is a professional engineering-grade cable manufacturer in China, supplying certified electrical cable solutions for building, industrial, mining, energy, and infrastructure projects worldwide.

With a 30,000 m² factory, 30 production lines, experienced engineers, and a strict quality control team, we provide reliable, traceable, and compliant cable products for international engineering applications. Our products are supported by certifications including SAA, UL, cUL, VDE, TÜV, CE, CB, IEC, BPS, and ISO.

We are committed to safety, quality, transparency, and long-term partnership. From raw material inspection to finished product testing, every batch is carefully controlled to ensure stable performance and dependable project use.

Greater Cable - Certified Quality. Reliable Supply. Engineering Value.

THHN/THWN-2 copper building wire for electrical metallic tubing

15K

Finished Projects

150+

professional staff

15K

happy clients

92+

awards & certifacates

PLANT EQUIPMENT

GLOBAL CERTIFICATIONS

moisture resistant THHN copper wire

CUSTOMER PHOTOS

moisture resistant THHN copper wire

INTERNATIONL TRANSPORTATION

Sea Freight

We offer reliable sea freight solutions for large-volume orders. Your goods are securely packed and shipped in containers, ensuring cost-effective delivery to ports worldwide.

Air Freight

For faster delivery, our air freight service ensures your products reach international destinations quickly, with careful handling and full tracking along the way.

International Express

Need urgent shipments? Our international express service delivers small to medium orders efficiently, providing door-to-door service with real-time tracking for peace of mind.

COOPERATIVE PARTNER

We are looking for a cooperative partner to expand our business.

abrasion resistant Copper THHN/THWN-2 Wire

Copper THHN/THWN-2 Wire for motor wiring

How To Cooperate With Us?

Simply share your requirements, receive our professional solution, confirm samples, and enjoy fast, reliable production and worldwide delivery - working with us is that easy.

Our address

Building 2, No. 40 Luxi 2nd Road, Liaobu Town, Dongguan City, Guangdong Province, China

Phone Number

+86 136 6257 9592

+86 135 1078 4550

E-mail

manager01@greaterwire.com

FAQ

What is the rated ampacity of 350 kcmil UL 83 copper THHN/THWN-2 wire?

Per NEC Table 310.15(B)(16), 350 kcmil copper THHN/THWN-2 carries a 90°C ampacity of 350 amperes at 30°C ambient temperature in dry locations - a 30A increase over the 300 kcmil gauge for heavier load capacity. Mandatory ampacity derating applies when 3 or more current-carrying conductors are bundled in a single raceway, or when installed in high-ambient environments. Final conductor sizing should always be validated by a licensed electrical engineer based on actual load calculations and project conditions.

Is this 350 kcmil PVC insulated wire suitable for outdoor service entrance or exposed rooftop runs?

It is approved for outdoor installations when routed inside approved conduit or raceway, thanks to its THWN-2 90°C wet-location rating that withstands rain, humidity and condensation. However, its PVC and nylon construction is not sunlight resistant: it cannot be run exposed to direct UV sunlight without a protective, sunlight-rated raceway. It is a standard specification for outdoor service entrance conduits and rooftop distribution runs when fully enclosed.

Does this 350 kcmil THHN/THWN-2 copper conductor meet UL 83 requirements for industrial plant wiring?

Yes. This wire is manufactured and tested in strict conformance with UL 83, the North American safety standard for thermoplastic-insulated building wires. Its flame-retardant PVC insulation and tough nylon jacket meet all required dielectric strength, thermal stability and temperature rating criteria. It fully complies with applicable NEC articles for commercial and industrial power distribution, making it a code-valid choice for plant main feeders and heavy equipment supply circuits.

What installation best practices apply to 350 kcmil large-gauge THHN/THWN-2 in conduit runs?

First, calculate conduit fill percentage strictly per NEC Chapter 9 Tables - large-gauge conductors quickly exceed allowable fill limits, which causes overheating and extremely difficult pulls. Second, follow minimum bending radius requirements to avoid damaging the PVC insulation and distorting the conductor stranding. Third, use appropriate cable pulling lubricant for long runs to reduce friction and prevent scuffing to the outer nylon jacket. While its Class B stranded copper construction offers good flexibility for this gauge, proper pull planning and rigging are still recommended for extended conduit runs.

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