Power Cord Jacket Types Explained

May 14, 2018 Tripp Lite
Tripp Lite

If you’ve been looking for a new or replacement detachable power cable, you might have seen an alphabet soup of abbreviations for the cable jacket type. Understanding these abbreviations will help you choose the correct power cable for your application.

Cable Jackets

Each of these letters designates a usage rating derived from the National Electrical Code. Here is the most common nomenclature used for power cable jackets:

  • S—Service Grade (Extra-Hard Service Grade if not followed by J, V or P); normally rated to 600V
  • J—Junior Grade; a “J” cord is rated for hard service up to 250-300V
  • V—Vacuum Cleaner Cord; light-duty cable
  • P—Parallel Cord; light-duty zip cord
  • T—Thermoplastic; most often polyvinyl chloride (PVC)
  • E—Elastomer; a copolymer that adds flexibility, especially in sub-freezing conditions
  • O—Oil-Resistant outer jacket
  • W—Outdoor; stands up to moisture and sunlight

Generally, the combination of these letters defines the various cable jacket types. The chart below is a glossary of the most common types in North America.

Common North America Cable Types

Type Description Jacket Material Application
SJT Junior Hard Service Thermoplastic Thermoplastic (PVC) insulated conductors and jacket Indoor use; tools and equipment, lights, power extensions
SJTW Junior Hard Service Thermoplastic, Outdoor Rated Moisture- and sunlight-resistant thermoplastic (PVC) insulated conductors and jacket Indoor/outdoor use; tools and equipment, lights, power extensions
SJOW Junior Hard Service Oil-Resistant Outdoor Rated Oil-, moisture- and sunlight-resistant thermoset insulated conductors and jacket Indoor/outdoor use; small motors and machinery
SVT Service Vacuum Thermoplastic Light-duty thermoplastic (PVC) insulated conductors and jacket Indoor use; small appliances such as vacuums, fans and lamps
SEOW Extra-Hard Service Thermoplastic Elastomer Oil-Resistant Outdoor Rated Oil-, moisture- and sunlight-resistant heavy-duty thermoplastic elastomer (TPE) insulated conductors and jacket Outdoor use in extreme weather conditions

Power cables and extension cables designed for hard-service indoor and indoor/outdoor use are available from Tripp Lite. These solutions have flexible PVC jackets and come in a variety of lengths, wire gauges and amperage ratings. All of Tripp Lite’s power cables are rated to ANSI/UL 62 and 817 and CAN/CSA C22.2 no. 21 and 49. Tripp Lite also provides hospital-grade power cables and extension cables to meet the specialized needs of healthcare facilities such as hospitals, clinics and physician’s offices.



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