Bonding a pull box

[Dsg319]

If your on a job utilizing cable tray we have to pull feeders and branch circuits in a cable assembly through pull boxes all the time. But our pull boxes are tied in to the stations grounding/bonding grid.

 

[LarryFine]

Unless the box gets crushed to the point of rupturing the cables and exposing an ungrounded conductor, I'm not seeing how you energize the box.

As an example to illustrate the NEC's importance of box grounding, consider that directly grounding an outlet box is mandatory, even in cases where directly grounding the receptacle is optional.

In other words, as important as a receptacle's grounding function is, the mounting means may be part of that pathway in most cases, but that same pathway may never be used to ground the box.

NEC safety concerns are as much about protecting the environment (and people) from the wiring as they are about protecting the wiring from the environment. A hot enclosure is dangerous.

 

[Ponchik]

In OP question the pull box is not likely to become energized. Conductors come n and go out. No splices. If there were splices, then likely to become energized will apply. IMO.

 

[electrofelon]

In OP question the pull box is not likely to become energized. Conductors come n and go out. No splices. If there were splices, then likely to become energized will apply. IMO.

The box is required to be bonded even if it is not likely to become energized. 250.4(A)(2) and (3)

 

[gadfly56]

Conductors are "just passing through" metal conduit as well. Do you believe it shouldn't be bonded either?

Sure, if there were metal conduits entering the box, you'd need to bond them. In this case, we are talking about PVC

 

[kwired]

From the OP:

Interesting enough, I’m getting conflicting answers. Do a metal pull box that has PVC conduit entering and exiting need to be bonded? Feeders are passing through.

Unless the box gets crushed to the point of rupturing the cables and exposing an ungrounded conductor, I'm not seeing how you energize the box. And if you do get to that point, you probably have far more worrisome issues than whether that box is grounded. Like the San Andreas fault shaking loose California into the eastern Pacific worrisome.

Though I agree with what you said, I don't see this being considered "not likely to become energized" by many AHJ's therefore it needs to be bonded somehow. As earlier mentioned the rule that allows passing through with no splicing and no bonding to the box only applies when the box already has other bonding means, particularly via metallic raceway entries.

 

[gadfly56]

Though I agree with what you said, I don't see this being considered "not likely to become energized" by many AHJ's therefore it needs to be bonded somehow. As earlier mentioned the rule that allows passing through with no splicing and no bonding to the box only applies when the box already has other bonding means, particularly via metallic raceway entries.

OK, let's take the bonding requirement at face value and turn now to practical matters; how? What would be your approach to bonding/grounding an exposed box and then a buried box. Assuming in case "b" that mere burial doesn't do the trick. Or does it?

 

[electrofelon]

OK, let's take the bonding requirement at face value and turn now to practical matters; how? What would be your approach to bonding/grounding an exposed box and then a buried box. Assuming in case "b" that mere burial doesn't do the trick. Or does it?

Typically the box would be bonded and grounded by the EGC run with the conductors that are entering the box. There is no exemption for situations where "there is no good way to bond the box". For example consider a metal raceway that transitions to PVC on both ends. Pretty much cant do that, gunna have to put a box in so you can access the EGC or run the metal raceway all the way to the next box or cabinet on one end of the run.