25+ year old 14/3 extension cord. Blue jacket. Still nice and flexible. Jacket stamped "-50C". Surprisingly, it is also stamped "SJTW-A". I thought flexible-in-cold carried the E, not the T designation. What is it that makes some extension cords flexible in cold weather?

  • I have found that "rubber" cords tend to be a lot more flexible in cold than the typical plastics, but they are also somewhat hard to find these days. – Ecnerwal Dec 9 '17 at 17:39

You may notice a child's outdoor toy blanches and cracks in 6 months from UV from sunlight, but your car's interior holds up for 20 years despite much hotter conditions. It is a different grade of plastic.

Also, nothing requires a cable claim every rating it's entitled to, or it may comply mostly, but fall technically short of what is needed for the rating. You're always allowed to make a great product.


Flexible cords have an entire section of the National Electric Code article 400. If I remember correctly T is thermoplastic, SJ is junior hard service, W is damp/ wet locations. I really don't remember A in a description.

  • Found this glossary: uswireandcable.com/glossary.html – Jerry French Dec 9 '17 at 16:51
  • I know there are many more cord types in the NEC. Than that listing, type E cable is elevator according to the NEC different than your link, also w is wet/damp but I think type w is also sunlight resistant so that would be the same but I did not find a listing in the NEC for A – Ed Beal Dec 9 '17 at 17:03
  • Per the document linked in Jerry's comment, "W-A" means weather approved. – Ecnerwal Dec 9 '17 at 20:32
  • I did look at the link but as I explained it differs from the NEC. – Ed Beal Dec 9 '17 at 23:57

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