UL® Conduit Coupling Marking Requirements

Not sure whether the rigid steel conduit coupling you are using has been manufactured and listed to UL safety standards? UL has released a bulletin clarifying the marking requirements for straight threaded conduit couplings shipped individually and in bulk. The clarification did not affect the requirements for couplings assembled on finished lengths of conduit supplied by the factory. Those couplings are identified by a single UL Certification Mark applied to the conduit. Straight threaded couplings sold individually or in bulk are required to bear the UL logo on the coupling and the complete UL Certification Mark on the smallest unit container. These marking requirements can be referenced in the UL Guide Pages included under Product Category DYIX. Listed straight threaded conduit couplings are also required to be stamped with the letters “EC” and a manufacturer’s identification, as part of the UL 6 Standard. So remember: If you want to ensure that your straight threaded conduit couplings have been manufactured and listed to the UL safety standard, look for the UL logo or Certification Mark, manufacturer’s identification, and the letters “EC” on the coupling. The effective date for the marking requirements is January 15, 2016. There may be couplings manufactured prior to that date without the UL logo or Certification Mark. If you are still not sure whether the product is acceptable, do not hesitate to the contact the product manufacturer for clarification.

July 2017