SOOW, SJOOW and SJTW Flexible Cord Reference
Compare common portable cord designations, voltage markings, jacket conditions, and application limits before checking the exact cord and connected equipment.
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Compare cord families
Start with the complete cord designation and its printed voltage rating. SOOW, SJOOW, and SJTW identify different portable-cord constructions; they are not interchangeable merely because the conductor size and number of conductors match. The following comparison describes common U.S. designations, not the suitability of a particular assembly.
| Designation | Voltage family | What the letters help identify | What still needs product data |
|---|---|---|---|
| SOOW | 600 V family | Service cord; oil-resistant insulation and outer jacket; W weather/water-resistance designation | Exact jacket material, temperature range, flexibility, cable diameter, and exposure limits. |
| SJOOW | 300 V junior-service family | J distinguishes the junior voltage family; OO and W describe the indicated resistance properties | The actual cord listing, size, conductor count, environment, and connector suitability. |
| SJTW | 300 V junior-service family | T identifies thermoplastic construction; W is an outdoor/weather-resistance designation | The product temperature range, handling conditions, and any separately marked oil resistance. |
The family comparison does not assign an ampacity. Read the actual product marking and instructions. A 600 V cord rating does not make a 300 V connector, attached device, or completed assembly suitable for 600 V.
Read the complete legend
| Field | Record | Common mistake |
|---|---|---|
| Type and ratings | Full designation, voltage and temperature markings, certification information | Treating one letter or a seller description as the full rating. |
| Conductor construction | AWG size, conductor count, grounding conductor identification and stranding | Assuming the count means the same thing in every product description. |
| Physical dimensions | Manufacturer outside diameter and permitted operating/bending conditions | Using nominal conductor area as the cord diameter. |
| Exposure conditions | The documented wet/outdoor, oil, chemical, sunlight and temperature conditions | Treating outdoor resistance as permission for every outdoor routing or exposure. |
| Assembly interface | Plug, connector, gland/strain-relief range and equipment instructions | Selecting a grip or connector only by conductor AWG. |
For example, a purchase description containing “12 AWG, three conductors” is incomplete without the cord type, ratings, outside diameter and equipment requirements. Keep the designation separate from the catalog number so a supplier substitution can be checked against the same requirements.
Check the application
A flexible cord is not automatically a permitted substitute for a fixed wiring method. OSHA 1910.305(g) distinguishes permitted uses from prohibited uses, including using flexible cord as a substitute for fixed wiring and certain routing through building openings or concealment. The exact workplace and installation requirements must be checked separately.
- Identify the equipment function and whether the intended flexible connection is permitted for that application.
- Collect the equipment instructions, supply conditions, duty and exposure information.
- Match the full cord specification and its terminals, plugs and strain relief to the documented combination.
- Check physical protection, routing, condition and inspection requirements under the applicable site process.
Do not infer a permitted installation from oil resistance, outdoor marking, jacket color or physical flexibility alone. Product resistance properties and the rules for how a cord may be used answer different questions.
Record before replacement
Retain the equipment identifier, complete original and proposed cord descriptions, connector specifications, manufacturer instruction reference and any unresolved difference. If the old cord cannot be identified, obtain the equipment requirements rather than choosing a visually similar jacket.
Use the job card for replacement and follow-up notes. The temporary-power cord screening tool checks entered current and voltage-drop conditions; it does not approve the wiring method. For fixed conductor and cable markings, use the existing wire-marking reference.