Portable Cords 101 for Contractors: Flexible, Durable, Code-Smart Choices

Updated: August 19, 2025

TL;DR: If it moves, flexes, gets dragged, or gets set up and torn down, you probably need a listed portable cord, not building wire. Start by matching the environment to the cord family. SOOW handles oil and abuse. SJOOW is lighter for cord-and-plug loads. SJEOOW and similar TPE cords stay limber in the cold. High-temp silicone leads survive heat. Stage and event work lives under Articles 520 and 525. Construction power falls under Article 590. Size for the load and length, protect with GFCI where required, and terminate with listed cord caps and strain reliefs. You can source common types like Portable Cords — SOOW, Portable Cords — SJOOW, and Portable Cords — SJEOOW directly from Revco in Suffolk County, NY.

Why this matters on the job

Portable cords are the muscle and sinew of temporary power. Job sites in Suffolk County throw everything at them: sand, salt air, winter cold, summer sun, forklifts, and the occasional poorly placed skid. A bad cord will split, swell, or crack, then your crew loses power and your inspector fails you. A good cord is listed to UL 62, has the right jacket, the right conductor class, and the right termination hardware, all used where the NEC permits flexible cords. That keeps production moving and callbacks down. You can spec and buy the core types on Revco’s site, like SJOOW portable cords and SOOW portable cords, then finish them with locking connectors and liquid-tight cord connectors for strain relief and ingress protection.

Fundamentals

What a “portable cord” is. A portable cord is a flexible cable assembly listed for temporary power and cord-and-plug equipment. UL 62 is the underlying product standard for most flexible cords and fixture wires, and it frames construction and performance for families like SOOW and SJOOW.

Alphabet soup, decoded.

• SJOOW: Junior hard service, oil resistant insulation and jacket, 300 V rating, rubber insulation with a CPE jacket. It fits cord-and-plug tools and appliances. See Omni Cable SJOOW and Revco’s SJOOW category.
• SOOW: Hard service, oil resistant insulation and jacket, 600 V rating. Ideal for heavier loads, portable distribution, and industrial service. Southwire’s 600 V SOOW line is EPDM insulation with a flexible CPE jacket, 90 C rating dry, water and oil resistant. Revco stocks SOOW reels and cuts.
• SJEOOW / SEOOW / STOOW: Thermoplastic elastomer constructions for cold-weather flexibility and sunlight resistance. Many list −50 C to 105 C ranges. Revco’s SJEOOW page features winter-ready cords.
• High-temperature silicone leads: Silicone rubber insulation with fiberglass braid for oven and furnace zones. Revco lists silicone rubber high-temp wire for these applications.
• Type W and Type SC: Heavier portable power in industry and entertainment. Type W is common for generator feeders and industrial temporary power. Type SC is the stage cable used under Article 520 venues.

Where cords are and are not allowed. Article 400 of NEC 2023 governs flexible cords. Use cords where Article 400 permits and do not use cords to replace fixed wiring or run through building cavities. OSHA enforces compatible workplace rules for continuous length, splices, and strain relief.

Ingress and strain. Cord grips and watertight plugs keep water out and reduce stress on terminals. Use listed fittings sized to the jacket. See liquid-tight cord connectors and Wetguard devices for field builds.

GFCI protection. Temporary power on construction sites needs GFCI protection in specific cases under 590.6. Event power has separate GFCI coverage under Article 525. OSHA 1910.305 also requires safe practices that intersect with these rules. Stock GFCI receptacles and devices for job carts and temp panels.

Code and compliance

Use NEC 2023 as adopted by your AHJ.

• Article 400 Flexible Cords and Cables. Focus on types, uses permitted, uses not permitted, ampacity, splices, and support.
• Article 590 Temporary Installations. Use 590.4 for feeders and branch circuits, 590.6 for GFCI. Build temp power to this article, not permanent rules, and plan the de-energize and removal.
• Article 520 Theaters and performance areas. Flexible conductors feeding stage equipment must be listed for extra hard usage. Type SC is standard in these spaces.
• Article 525 Carnivals, circuses, fairs. Outdoor public events have unique GFCI and wiring protection rules. Do not assume Article 590 applies in place of 525.
• OSHA 1910.305 in workplaces. Continuous lengths without improper splices, listed strain relief, and prohibited routing through walls and ceilings. OSHA confirms there is no “90-day rule” blanket limit for all temporary wiring.

Selection steps

Step 1: Match the environment.

• Heavy abuse, oil, 600 V gear: SOOW. EPDM insulation and CPE jacket tolerate oil and impact.
• Light to medium duty, 300 V cord-and-plug: SJOOW. Lighter handling, lower cost, still oil and water resistant.
• Cold weather and sun: SJEOOW or SEOOW. Choose cords with published −50 C flexibility and sunlight resistance.
• High heat: Silicone rubber lead wire for terminations near ovens.
• Stage and event feeders: Type SC or Type W as engineered under Articles 520/525.

Step 2: Confirm voltage rating. 300 V families are not interchangeable with 600 V families. Match the equipment and overcurrent devices to the jacket marking and listing.

Step 3: Size for load and length. Choose AWG that carries the nameplate current with acceptable drop. For common 120 V, 20 A tools on 50 to 100 ft cords, 12 AWG is usually right. Use NEC ampacity framework and ambient corrections when conditions vary from 30 C.

Step 4: Conductor count and grounding. Use two hots plus EGC for single phase, three hots plus EGC for three phase. Add control pairs when specified.

Step 5: Terminations and strain relief. Use listed cord caps, inlets, and connector bodies that match the NEMA pattern and environment. Select locking connectors such as Leviton CS6364C and add liquid-tight cord connectors at entry points.

Step 6: Code check. Verify Article 400 allows the use. If the setup is temporary construction power, follow Article 590. If it is a show or fair, use 520 or 525 respectively. Provide GFCI protection per the applicable article.

Sizing or configuration examples

Example 1: 1.5 hp 120 V portable compressor on a 100 ft run. Nameplate current is 15 A. Circuit is 20 A, single phase. Choose a 12 AWG SJOOW extension or step up to SOOW for tougher duty. Provide GFCI per 210.8 if part of permanent wiring or 590.6 if temporary job power.

Example 2: 5 hp 480 V portable pump on a construction site. Three phase load near 7 to 8 A. Use SOOW 600 V four conductor cord. Terminate with locking devices listed for the environment. Place under Article 590 with GFCI where required. Protect entries with liquid-tight cord connectors and locate a local disconnect.

Example 3: Winter event power in Montauk. Outdoor stage lighting on 20 A circuits. Use SJEOOW or premium cold-flex SOOW with sunlight resistance. Provide GFCI per Article 525. Protect cables from vehicles and keep terminations elevated. Revco’s extension cords category includes SJEOOW assemblies.

Installation and wiring notes

• Follow the listing. Respect jacket temperature ranges and chemical resistance as published by manufacturers.
• Continuous length. Flexible cords are used in continuous lengths. Repairs are limited and must maintain the jacket and usage characteristics.
• Strain relief. Every cord entering a box or device needs a strain relief sized to the jacket. Use cord connector fittings.
• Wet locations. Use wet-location rated devices and covers like weatherproof device covers and watertight connectors.
• Routing and protection. Do not run cords through holes in walls, ceilings, or floors. Protect from abrasion and traffic.
• Terminations. Install listed locking connectors that match the circuit. Verify polarity and equipment grounding continuity before placing in service.

Testing, commissioning, and documentation

• Continuity tests for each conductor and equipment ground.
• Insulation resistance checks within cord and device limits.
• GFCI self-test or tester verification on receptacles and breakers.
• Visual inspection log for jacket cuts, flattened regions, or hot spots.
• Label lengths and destinations for repeatable setups.
• Keep a reliable tester from Greenlee in each gang box.

Troubleshooting

• Repeated breaker or GFCI trips. Check for neutral-ground faults, wet interiors, or failed devices.
• Voltage sag under load. Replace thin cords with 12 AWG for 20 A circuits.
• Hot connectors. Tighten terminals, right-size the cord clamp, and replace worn caps.
• Stiffness in winter. Switch to SJEOOW or a premium rubber cord with a published −50 C flexibility rating.
• Oil-soaked jackets. Replace with SOOW and reduce exposure.

FAQ

Can I use a portable cord for permanent wiring?
No. Article 400 lists uses not permitted. OSHA forbids using cords as a substitute for fixed wiring.

What gauge should I use?
Size to the nameplate and the run length. For 20 A tools on 50 to 100 ft, 12 AWG is a safe starting point. Adjust for ambient temperature as needed.

Are all portable cords waterproof?
No. Use cords and devices listed for wet locations and add weatherproof covers as needed.

What about generator feeders?
Use 600 V rated cords like SOOW or Type W as engineered. Provide GFCI per Article 590 and device listings.

What should I stock on the truck?
12/3 SJOOW extensions, 10/3 SOOW whips, locking connectors, liquid-tight cord connectors, GFCI receptacles, and a tester.

Common mistakes to avoid

• Replacing fixed wiring with cords.
• Running cords through walls or ceilings.
• Using 16 AWG on 20 A tools.
• Skipping strain relief.
• Using 300 V cords on 480 V systems.
• Mismatching NEMA patterns on caps and inlets.

Parts to stock and related products

• Portable Cords — SOOW for 600 V heavy service.
• Portable Cords — SJOOW for 300 V tools and lights.
• Portable Cords — SJEOOW for cold and sun.
• Extension cords for quick deploy.
• Watertight locking connectors and Black & White locking connectors for field builds.
• Liquid-tight cord connectors for enclosure entries.
• High-temperature silicone lead wire for furnace zones.
• GFCI receptacles for carts and panels.
• Greenlee testers to commission cords and temp power.

When to call the AHJ or engineer of record

Call when you are building temporary power for a public event, when a venue is under Articles 520 or 525, when routing cords near public areas, when paralleling cords, or when loads exceed 60 A per cord. In Suffolk County, inspectors often require a site walk for fairs and large generators before energization.

Disclaimer

Always verify requirements with your Authority Having Jurisdiction and the current manufacturer instructions before you order or install.

Credits

Author: Revco Editorial Team — Electrical Content Editor — Writes contractor-first guides backed by code and manufacturer sources.

Technical review: Pending — add approved name/credential — Role

Contact: (631) 283-3600

About Revco Lighting & Electrical Supply

Since 1978, Revco Lighting & Electrical Supply has been helping professionals bring their projects to light—literally. As a go-to source for lighting and electrical products across Long Island, NY and nearby areas, we specialize in supporting contractors, builders, and industry experts with practical solutions and dependable service. Whether it’s a complex commercial build or a simple residential upgrade, we’re here to make sure you have what you need, when you need it.

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