Portable Cord Types: How to Choose SOOW, SJOOW and SJEOOW
Last updated:August 7, 2026
TL;DR
Choose portable cord by its permitted use, voltage rating, conductor size,conductor count, jacket properties, temperature range and environment. SOOW iscommonly used for 600-volt heavy-duty applications. SJOOW is a lighter 300-voltoption. SJEOOW commonly uses thermoplastic elastomer materials for cold-weatherflexibility. Always verify the complete product marking and manufacturer datainstead of selecting cord by its type letters alone.
Portable cord is used where equipment moves, vibrates or must be connected anddisconnected. Common examples include portable tools, temporary power equipment,machinery, lighting and cord-and-plug-connected loads.
Flexible cord is not a general replacement for permanent wiring. The applicationmust be permitted by the applicable electrical code, workplace rules, equipmentlisting and manufacturer instructions.
Portable cord comparison
| Cord type | Typical voltage rating | Common characteristics | Potential uses |
|---|---|---|---|
| SJOOW | 300 volts | Junior-service construction with oil-resistant insulation and jacket.Lighter than comparable SOOW cord. | Portable tools, lighting and cord-and-plug-connected equipment when theproduct ratings and application allow it. |
| SOOW | 600 volts | Flexible heavy-duty construction with oil-resistant insulation and jacket.Product-specific listings may also cover water, weather, sunlight, abrasionand other conditions. | Portable equipment, machinery, temporary power and demanding industrialapplications when properly selected. |
| SJEOOW | 300 volts | Commonly manufactured with thermoplastic elastomer insulation and jacket.Some products are designed for improved low-temperature flexibility. | Outdoor tools, lighting and portable equipment where the specific productis listed for the temperature and environment. |
These are general comparisons. Temperature limits, wet-location suitability,sunlight resistance, oil resistance and permitted uses must be confirmed from theindividual product specifications and markings.
What the portable cord letters mean
Portable cord type designations provide useful information, but they do not tellyou everything about the product.
- S:Service cord.
- J:Junior-service construction, commonly rated 300 volts.
- E:Thermoplastic elastomer construction.
- O:Oil-resistant outer jacket.
- OO:Oil-resistant insulation and outer jacket.
- W:Suitable for outdoor use when marked and listed accordingly.
Do not treat those letters as the complete specification. Check the voltage,conductor size, number of conductors, temperature range, overall diameter, ampacity,approvals and application information for the exact item being considered.
SOOW portable cord
SOOW is a common choice when a 600-volt flexible cord is needed for portable tools,equipment, machinery or temporary power. Many SOOW products use EPDM conductorinsulation and a chlorinated polyethylene jacket, but construction can vary bymanufacturer.
SOOW should not be selected solely because the job is outdoors or because the cordmay encounter oil. Confirm the particular item's environmental ratings, temperaturerange and approvals.
SJOOW portable cord
SJOOW is commonly rated 300 volts and is generally lighter and easier to handle thancomparable SOOW cord. It can be a practical choice for portable tools, lighting andcord-and-plug equipment that does not require a 600-volt cord.
The lighter construction does not make every SJOOW cord suitable for every extensioncord or jobsite application. Confirm conductor size, ampacity, length, environmentand equipment requirements before selection.
SJEOOW portable cord
SJEOOW commonly uses thermoplastic elastomer materials. Some SJEOOW products remainmore flexible at low temperatures than conventional cord constructions, making themuseful for cold-weather work.
Low-temperature ratings vary. Do not assume every SJEOOW cord carries the sameminimum temperature, sunlight rating or wet-location approval. Check the productdata before specifying it for winter or outdoor use.
How to select portable cord
- Confirm that flexible cord is permitted for the application.
- Check the equipment nameplate and circuit voltage.
- Obtain the required conductor size from the approved equipment or project information, or from the qualified electrical professional responsible for the circuit.
- Provide the intended cord length and load information so any required voltage-drop evaluation can be completed by the qualified person responsible for the circuit.
- Choose the correct number and type of conductors.
- Match the jacket and temperature rating to the environment.
- Select compatible plugs, connectors and strain-relief fittings.
- Confirm grounding and ground-fault protection requirements.
- Verify branch availability and cut-length options before dispatching a crew.
1. Confirm the application
Start by determining why the load requires flexible cord. OSHA permits flexiblecords for specific applications, including portable equipment, moving parts,vibration isolation and qualifying temporary wiring.
Flexible cord generally cannot be used as a substitute for a structure's fixedwiring. It also cannot normally be concealed behind walls or run through holes inwalls, ceilings or floors unless a permitted use applies. Construction rules containa specific allowance for flexible cords to pass through doorways or other pinchpoints when the cord is protected from damage, so doorway use should not be treatedas an absolute prohibition.
2. Check the voltage rating
A 300-volt cord is not interchangeable with a 600-volt cord. Select a cord rated forthe circuit and equipment. Voltage rating alone does not establish the cord'sampacity or environmental suitability.
3. Size for load and length
Use the conductor size required by the approved equipment information, projectdocuments or the qualified electrical professional responsible for the circuit.Portable-cord ampacity, conductor count, temperature conditions, circuit protectionand cord length can all affect the selection. Any voltage-drop evaluation should bebased on the actual load and length rather than a universal rule.
Longer cords can produce more voltage drop. Motors, compressors and other loads withsubstantial starting current may require additional evaluation. Do not rely on auniversal rule such as “12 AWG is always enough for 100 feet.”
4. Choose the correct conductor count
Match the number of conductors to the actual circuit. Depending on the system andequipment, the cord may need one or more ungrounded conductors, a grounded conductor,an equipment grounding conductor or additional control conductors.
Do not assume that every single-phase load uses three conductors or that everythree-phase load uses four.
5. Match the environment
Review the complete product data when the cord may be exposed to:
- Water or damp conditions
- Sunlight and outdoor weather
- Oil, chemicals or solvents
- High or low temperatures
- Abrasion, impact or vehicle traffic
- Frequent flexing or equipment movement
Protect cords from sharp edges, doorways, pinch points and traffic. A heavy-dutyjacket does not remove the need for physical protection and proper routing.
6. Select compatible terminations
Plugs, connector bodies, inlets and cord grips must match the circuit, cord diameter,conductor size and environment. Use listed components and follow their assembly andtorque instructions.
The strain-relief fitting should prevent pulling force from being transmitteddirectly to the terminals. A fitting selected only by trade size may not properlygrip the cord jacket.
Browse liquid-tight cord connectors and strain-relief fittings
Construction-site ground-fault protection
OSHA requires construction employers to use GFCI protection or an assuredequipment grounding conductor program to protect employees. Its construction GFCIprovision specifically addresses qualifying 120-volt, single-phase, 15- and20-amp receptacle outlets that are not part of the permanent wiring and are beingused by employees.
An assured equipment grounding conductor program has written procedures,inspection, testing, recordkeeping and competent-person requirements. It is notsimply a substitute adapter or a quick continuity check.
Additional requirements may apply under NFPA 70, project specifications, theequipment listing or local rules.
Inspecting and maintaining portable cords
Construction-site cord inspection requirements depend in part on the employer'sground-fault protection program. When an OSHA assured equipment grounding conductorprogram is used, covered cord sets, plugs, receptacles and cord-and-plug-connectedequipment must be visually inspected before each day's use. Regardless of theprogram used, damaged cords should be removed from service. Look for:
- Cuts, cracks, worn areas or a penetrated jacket
- Flattened, crushed or overheated sections
- Loose cord grips or pulled-back jackets
- Missing, bent or damaged plug blades and grounding pins
- Discoloration, melted material or heat damage at connectors
- Signs that the cord was run over, pinched or sharply bent
Remove damaged equipment from service. Do not cover a penetrated jacket withelectrical tape and return the cord to use. Where repair is allowed, the repairmust preserve the cord's insulation, jacket and usage characteristics and shouldbe performed under an approved procedure by a qualified person.
Deenergize a cord before opening, adjusting or replacing its terminations. A hotconnector can indicate a loose connection, worn contact, overload, contamination,improper assembly or an incompatible device.
Common portable-cord mistakes
- Using flexible cord as permanent building wiring
- Running cords through walls, ceilings or floors, or using doorways and otherpinch points without the protection required for the applicable installation
- Selecting cord only by its AWG size
- Using 300-volt cord on a circuit requiring a 600-volt rating
- Ignoring voltage drop on long runs
- Assuming every cord marked “W” has identical environmental ratings
- Mismatching plugs, connector bodies and receptacle configurations
- Using a cord grip that does not match the actual jacket diameter
- Skipping required GFCI protection or grounding-program procedures
- Continuing to use cords with damaged jackets, plugs or grounding pins
Code note for Long Island contractors
New York's 2025 Uniform Code took effect on December 31, 2025. The 2025 BuildingCode of New York State references NFPA 70 for applicable electrical systems.Project requirements can also depend on the permit date, municipality, work type,equipment listing and Authority Having Jurisdiction.
Temporary construction power, entertainment installations, fairs and publicevents may involve different code articles and permitting requirements. Confirmthe applicable requirements before selecting or assembling the cord system.
Frequently asked questions
What is the difference between SOOW and SJOOW cord?
SOOW is commonly rated 600 volts. SJOOW is commonly rated 300 volts and generallyhas a lighter construction. Both designations indicate oil-resistant insulationand jackets, but the exact temperature, weather and application ratings depend onthe individual product.
Is SOOW cord waterproof?
Do not assume that every SOOW product or completed cord assembly is waterproof.Check the exact cord, plug, connector, enclosure and fitting ratings. The completedinstallation is only as suitable as its least-protected component.
Can portable cord be used for permanent wiring?
Flexible cord generally cannot replace a structure's fixed wiring. It may be usedonly for permitted applications and must not normally be concealed or routedthrough walls, ceilings or floors.
What gauge portable cord should I use for a 20-amp tool?
There is no safe answer based only on the branch-circuit rating. Check the toolnameplate, actual load, cord length, voltage drop, cord ampacity, conductor count,temperature, circuit protection and manufacturer instructions.
Does every construction extension cord need GFCI protection?
OSHA requires construction employers to use GFCI protection or an assuredequipment grounding conductor program. The exact application depends on thereceptacle, circuit, wiring and work conditions. Follow OSHA 1926.404 and anyadditional electrical-code or project requirements.
Can a damaged portable cord be repaired?
OSHA's construction rule allows repair by splicing only for hard-service flexiblecord No. 12 AWG or larger, and the completed splice must retain the insulation,outer-sheath properties and usage characteristics of the original cord. The ruledoes not extend that repair permission generally to junior hard-service cord. Adamaged cord should be removed from service until an allowed repair or replacementis completed; a penetrated jacket should not simply be covered with tape andreturned to use.
Need portable cord for an upcoming job?
Browse Revco's portable cord categories by cord type, conductor size, voltage andnumber of conductors. Product availability, reel packaging and cut-length servicecan vary by item and branch.
Browse portable cords and cables
For a specific length, configuration or job requirement,contact your nearest Revco branchbefore sending someone to pick it up.
Safety and code disclaimer:This article provides general productselection information. It does not replace electrical design, engineering, workplacesafety procedures, NFPA 70, OSHA requirements, manufacturer instructions or directionfrom the applicable Authority Having Jurisdiction.