Grounding locknuts question

[Tulsa Electrician]

Working on a service where there is a 1000 amp service disconnect. Then running a feeder to a wireway feeding individual meters mains. Using the ten foot tap rule.

The utility meters are bonded neutral meter mains. Using the exception for grounded conductor on load side of the service disconnect 250.142.(B) (2). I meet all three, adjacent, no GFP, properly sized grounded conductor.

Using all metal raceways. No wire type EGC from service disconnect to the meter mains.

The question is, would grounding lock nuts be required since these are feeders.

I would think it's a good idea however don't see where it's required unless I missed it some where.

 

[infinity]

Using all metal raceways. No wire type EGC from service disconnect to the meter mains.

The question is, would grounding lock nuts be required since these are feeders.

No bonding locknuts or bushings would be required for a feeder unless the voltage was above 250 volts to ground and there were concentric or eccentric KO's.

 

[Tulsa Electrician]

Thank you.

 

[Jaybone812]

Working on a service where there is a 1000 amp service disconnect. Then running a feeder to a wireway feeding individual meters mains. Using the ten foot tap rule.

The utility meters are bonded neutral meter mains. Using the exception for grounded conductor on load side of the service disconnect 250.142.(B) (2). I meet all three, adjacent, no GFP, properly sized grounded conductor.

Using all metal raceways. No wire type EGC from service disconnect to the meter mains.

The question is, would grounding lock nuts be required since these are feeders.

I would think it's a good idea however don't see where it's required unless I missed it some where.

They are feeder conductors so 250.92 doesn’t apply , they would only require a additional method of bonding to comply with 250.97

 

[ramsy]

 

[Jaybone812]

View attachment 2576678

Ryan made an updated version of that flow chart

 

[ramsy]

Ryan made an updated version of that flow chart

Nice improvement, which ads hazardous location, and describes "similar enhanced bonding", which would include an EGC.

The only dependency is poor wording with nonmetallic raceways, which do require EGC bonding to the raceway devices.

 

[infinity]

I prefer the flow chart in post #5 but I have found that this is not 100% accurate. Bonding at only one end is not code compliant. Two enclosures over 250 volts to ground with eccentric/concentric KO's and not listed for bonding would require bonding at both ends.