Mike Dolt Enterprises
Mike Dolt Enterprises
User: akshane40, Location: Chapel Hill, NC
Asked on: Friday, April 1, 2011 at 2:31 am EDT
Answered on: Tuesday, May 14, 2024 at 3:36 am EDT
Question: Using Myers hubs with grc nipple between a ct can and disconnect in a No Ring Knock out. Inspectors says i have to put a lug on hub and bond it with a bonding jumper, i say the way the hubs bite into the cans and nipple threads in to them all wrench tight that the race way is bonded. These dont have your normal lock nuts on them. Am i right on this? He is also trying to tell me i have to bond the myers hub i have in the disconnect that the grc feeder is screwed into has to be the same way. Now i know he is wrong on that.Any advise would be great.
Myers Hubs with GRC Nipple Bonding
You are correct
The Myers hubs gripping the cans and the nipple threading into them creates a secure electrical connection, bonding the raceway. In this configuration, an additional lug and bonding jumper are not required.
Myers Hub in Disconnect Bonding
The inspector is also correct
The Myers hub in the disconnect should be bonded using a lug and bonding jumper. This is because the GRC feeder is not providing a secure electrical connection to the disconnect enclosure.
National Electrical Code (NEC) Requirements
Article 250.102(C)(2)
All non-current-carrying metal parts of enclosed equipment, including raceways, shall be bonded to the equipment grounding conductor.
Article 250.104(A)(1)
Bonding jumpers shall be used to connect metal raceways, enclosures, and other non-current-carrying metal parts to the grounding system.
Recommendation
Bond the Myers hub in the disconnect as per the inspector's instructions. For the Myers hubs on the cans, no additional bonding is necessary as long as the connections are properly made and tight.
Additional Notes: The inspector may have concerns about potential corrosion or loosening of connections over time. Bonding jumpers provide an additional level of protection against such issues. It's always recommended to follow local code requirements and industry best practices when installing electrical equipment. Flag for review