RMC to FMC - Quiz (Difficulty Level= Medium)

[jar546]

You are looking at a trough that feeds to condominium panelboards. The service disconnect and meters with disconnects will be mounted below just as it was before. The electrician does not want to replace the EMT conduits coming up into the bottom of this trough, and instead is opting to use FMC probably because the are lazy and don't want to thread pipe. As a result, bond between the service disconnect and meter packs that feed up into this will be essentially gone because FMC is only good for 20amps.
With that being said, they will have to ensure the trough is electrically bonded to the service and meter stacks. The EMT that goes to each condo unit provides the equipment ground for the panelboards, which is why you don't see a 4th wire. What are the options or requirements for connecting the trough to the service disconnect with meter stacks?

 

[Gregg Harris]

article 376- exception #2 250.142{B}