Question
Are grounding electrode acorn-type clamps Listed for use with two grounding electrode conductors?
Answer
Acorn clamps for grounding electrode conductors are UL Certified (Listed) for connection to only a single conductor. 2023 National Electrical Code® NEC® 250.70(A) also requires that no more than one conductor be connected to the grounding electrode by a single clamp or fitting unless the clamp or fitting is Certified (Listed) for multiple conductors.
Certified acorn clamps are evaluated for compliance with UL 467, the Standard for Safety for Grounding and Bonding Equipment, and UL Certified (Listed) under the product category Grounding and Bonding Equipment (KDER) . The guide information and UL Certifications (Listings) can be viewed on UL Product iQ® at http://www.ul.com/piq; enter KDER at the search field.
Question
Are bonding-type locknuts Listed for use on electrical metallic tubing (EMT) or conduit fittings, or only for use on threaded rigid conduit?
Answer
Individual grounding or bonding type locknuts that have an integral set screw to bond an enclosure to the lock nut and not included as part of a grounding and bonding type conduit fitting are investigated only for use on rigid metal or intermediate metal conduit. Because they are not included as part of a Certified (Listed) conduit fitting, grounding or bonding-type locknuts are not investigated by UL Solutions for use on EMT or conduit fittings unless specifically requested and Certified (Listed) for that use. UL Certified (Listed) EMT and conduit fittings are provided with a locknut as part of the fitting.
Always check the manufacturer’s information or instruction sheet for the locknut to determine its intended wiring method.
Grounding and bonding type locknuts are evaluated for compliance with UL 467, the Standard for Safety for Grounding and Bonding Equipment, and UL Certified (Listed) under the product category Grounding and Bonding Equipment (KDER). EMT fittings are UL Certified (Listed) under the product category Electrical Metallic Tubing Fittings (FKAV) and conduit fittings are UL Certified (Listed) under Conduit Fittings (DWTT). Both categories products are evaluated for compliance with UL 514B, the Standard for Safety for Conduit, Tubing, and Cable Fittings. The guide information and Certifications (Listings) can be viewed on UL Product iQ at http://www.ul.com/piq; enter KDER, FKAV or DWTT at the search field.
Question
Effective Jan. 1, 2023, NEC 230.46 requires wire connectors used for splicing or tapping conductors on the line side of the service to be Certified (Listed) as suitable for this use. How will these connectors be marked to identify use on the line side of service equipment?
Answer
Wire splicing and tap connectors are UL Certified (Listed) under the product category Wire Connectors and Soldering Lugs (ZMVV). Wire splicing and tap connectors investigated for use on the line side of service equipment are marked on the connector, the smallest unit container or on an information sheet placed in the smallest unit container with one of the following: “SR” or “Suitable for use on the line side of the service equipment,” or equivalent.
The guide information and Certifications (Listings) for ZMVV can be viewed on UL Product iQ at https://www.ul.com/piq; enter ZMVV at the search field. Searching UL Product iQ is complimentary; registration is required for full access.
Note: We are now UL Solutions. Learn more about our new brand at https://www.ul.com/ulsolutions.
