250 MCM 3C VNTC Tray Cable w/ Ground Type TC-ER (THHN PVC 600V)

250 MCM 3-Conductor VNTC (Vinyl Nylon Tray Cable) with Ground (Numbered Conductors) is a heavy-duty, industrial-grade power feeder cable engineered for installation in open cable trays, structural conduits, and industrial wireways. Comprising three standalone 250 kcmil (MCM) stranded bare copper power conductors alongside a dedicated bare copper grounding wire, this multi-conductor assembly utilizes high-performance THHN/THWN-2 insulation cores wrapped in a rugged, sunlight-resistant Polyvinyl Chloride (PVC) outer jacket.

Unlike standard commercial cables that use distinct colored insulation for phase tracking, this industrial variation features uniform black insulation across all power legs, with each conductor uniquely identified by high-visibility, wear-resistant surface numbers (Conductor 1, Conductor 2, Conductor 3) printed continuously along the core. The round profile, numbered tracking system, and integrated grounding infrastructure provide maximum durability and streamlined termination, making it an ideal choice for high-capacity industrial motor feeds, main panel distribution entries, and utility branch circuits.

AMPACITY RATINGS (NEC 310.16)

• 60C Terminal Rating: 215 AMPS This is the baseline engineering safety rating. Use this value for final circuit sizing under normal operating conditions when connecting to standard equipment terminals or legacy breaker lugs restricted to 60C constraints.

• 75C Terminal Rating: 255 AMPS This is the standard engineering design rating. Use this value for most standard modern terminal connections and commercial distribution control setups, as most industrial equipment lugs are restricted to 75C terminations.

• 90C Terminal Rating: 290 AMPS This is the maximum capacity rating. Use this value strictly as the baseline calculation factor when adjusting or derating for high ambient operating temperatures, or when bundling multiple high-amperage tray cables together in tightly packed industrial raceways.

Key Features

• Industrial Numbered Conductor Core: Eliminates traditional color-coding in favor of alpha-numeric tracking (1, 2, 3 printed on the insulation). This standard industrial layout reduces phase confusion on large jobsites and streamlines connections to matching numbered terminal blocks.

• High-Capacity Power Distribution (250 MCM): Provides substantial power-carrying capacity with premium bare copper, making it an excellent choice for three-phase heavy machinery loops, high-draw industrial sub-panels, and main transformer distribution connections.

• Integrated Bare Copper Ground Wire: Includes a factory-installed, dedicated bare copper grounding conductor twisted within the core, ensuring a reliable, low-impedance fault current path without the need to pull an independent grounding line.

• Dual THHN / THWN-2 Conductor Insulation: Inner copper conductors are wrapped in high-dielectric PVC and topped with a rugged clear nylon skin. This dual-layer architecture ensures superior resistance to oil, gasoline, moisture, and insulation scraping during difficult installations.

• Direct Burial & Sunlight Resistant: Protected by an extruded, flame-retardant outer PVC jacket that forms an impermeable barrier against harsh ambient conditions, making it safe for open air tray runs, direct direct-burial trenching, or wet environments.

• Highly Conductive Bare Copper: Manufactured with high-purity, soft-annealed stranded bare copper conductors to deliver optimal electrical conductivity, minimal line resistance, and sufficient physical flexibility for long pulled runs.

• Rigorous Industrial Flame Ratings: Engineered to prevent the migration of fire across open structural paths, fully certified to pass the demanding IEEE 1202 / UL 1685 vertical tray flame tests.

Common Applications

• Main Feeders & Service Entrances: Injecting raw power from outdoor utility transformers into high-capacity indoor distribution panels, switchgear arrays, and main disconnect hubs.

• Industrial & Heavy Manufacturing Layouts: Routing high-amperage power across industrial environments, paper mills, foundries, mining sites, and petrochemical operations via open indoor or outdoor cable trays.

• Direct Burial Site Distribution: Burying underground branch and feeder circuits between commercial facilities, outer maintenance hubs, outbuildings, and municipal wastewater treatment zones.

• Hazardous Environment Deployment: Approved under strict National Electrical Code provisions for installation within Class I, Division 2 hazardous industrial locations.

Circuit Identification: Standard Industrial Numbering Method

• Conductor 1: Black Insulation printed with “1” or “ONE”

• Conductor 2: Black Insulation printed with “2” or “TWO”

• Conductor 3: Black Insulation printed with “3” or “THREE”

• Dedicated Ground: 4 AWG Stranded Bare Copper

• Note: VNTC constructions also include a continuous printed identification code on the surface of the jacket for cable type and structural standard tracking.

Technical Specifications

• Conductor Size: 250 MCM (250 kcmil)

• Number of Power Conductors: 3

• Conductor Type: Stranded Bare Copper

• Ground Wire Size: 4 AWG Stranded Bare Copper

• Insulation Material: PVC with Nylon Skin (THHN/THWN-2)

• Jacket Material: PVC (Polyvinyl Chloride) – Black

• Voltage Rating: 600 Volts RMS

• Maximum Temperature Rating: 90C Dry / 90C Wet Continuous Operating

• Flame Test Ratings: IEEE 1202, UL 1685 Vertical Tray Flame Test, FT4

• Compliance Standards: UL 1277 (Type TC), NEC Article 336, Type THHN/THWN-2 Conductors, RoHS Compliant

Technical Note: When engineering layouts with high-capacity 250 MCM VNTC tray cable, tracking raceway space and ambient heat buildup is vital. Since this is a 3-conductor configuration with a ground wire, it constitutes three current-carrying conductors under normal balanced loading conditions, meaning ampacity derating is generally not required per the baseline requirements of NEC Article 310.15(C)(1) unless bundled with other cables. However, if the circuit feeds non-linear loads (such as heavy variable-frequency drives or electronic ballasts), harmonic neutral currents may require the neutral to count as a current-carrying line. In all cases, final breaker sizing must align with the terminal temperature limitations of the connected equipment (typically the 75C rating of 255 Amps).

CABLE TYPE: 250 MCM / 3-Conductor Stranded Round THHN/PVC Type TC Tray Cable with Ground (Numbered Conductors)

DISCLAIMER: The technical information provided is for general reference only. Large-scale industrial power distribution paths, tray layouts, and machinery connections must strictly adhere to the National Electrical Code (NEC), local building structures, and relevant industrial safety parameters. Always cross-reference the official product submittal data sheet from the chosen manufacturer prior to finalizing physical system designs or cutting structural cable lengths.