Bonding of motor frame via the buried ground 'loop'

[Dale001289]

There are some here on site that think an additional, external bonding conductor, i.e. #2AWG, #2/0, or #4/0, from the (equipotential) grounding grid 'loop' is required to each motor frame.
From what I can determine per NEC, the motor frame is already bonded via the EGC in the motor termination box and an external bond is not required.
Comments?

 

[infinity]

The EGC connection is required by the NEC. The secondary connection you've mentioned is optional if it makes someone feel warm and fuzzy. However it cannot be used as a replacement for the EGC .

 

[Isaiah]

There are some here on site that think an additional, external bonding conductor, i.e. #2AWG, #2/0, or #4/0, from the (equipotential) grounding grid 'loop' is required to each motor frame.
From what I can determine per NEC, the motor frame is already bonded via the EGC in the motor termination box and an external bond is not required.
Comments?

The additional bonding from the loop to the motor frame is not required by NEC.
This would be a client or specification option


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[don_resqcapt19]

It is a common industrial specification, likely dating back to the extensive use of ungrounded systems in industrial facilities, years ago.
However as others have said not required by the code. If it is a project specification, just include the costs in the project and add to your profit.

 

[suemarkp]

Could be use specific. If it is a pool pump motor, it needs an external bonding lug. Not sure for barn application where there is an equipotential grid in the floor. Under normal use cases, I would expect it to make no difference.