Bonding required

[ecole]

Hello everyone, I've been pounding my head in various handbooks, but I'm looking for some help with interpretation.


-I've been struggling to determine if 2 bond bushings are required on a task for a bit. We've run a conduit from the electrical room, down a tunnel space about 30 feet and then the 4/0 is freely mounted to the concrete surface.
-Both ends of this conduit lack a termination. Side A stops 6" or so away from a ground bar in the electrical room, where the 4/0 is bonded, and we have installed a bond bushing with solid #6 to bond the RMC to the GEC on this end. End B, stops no where in particular under the platform, so that the 4/0 can then be periodically cad welded to a #6 jumper that bonds our boxes.
-The RMC exists in this instance exclusively to protect the 4/0 from potential physical damage. The only thing in the RMC is our 4/0.
-Is a bond bushing in this instance required on both ends of the RMC in question? I've been back and forth between 250.64(E) and 250.86 with a few co-workers with no conclusion. Thanks for any help on this in advance.

 

[infinity]

Both ends of this conduit lack a termination. Side A stops 6" or so away from a ground bar in the electrical room, where the 4/0 is bonded, and we have installed a bond bushing with solid #6 to bond the RMC to the GEC on this end. End B, stops no where in particular under the platform, so that the 4/0 can then be periodically cad welded to a #6 jumper that bonds our boxes.

A bonding bushing is required wherever the conductor exits and enters the metallic ferrous raceway. Also the bonding jumper to the bushing cannot be smaller than the GEC within the metallic raceway.

 

[ecole]

A bonding bushing is required wherever the conductor exits and enters the metallic ferrous raceway. Also the bonding jumper to the bushing cannot be smaller than the GEC within the metallic raceway.

I actually think I figured this out but wanted to reply, thanks and share what I was messing up.
I haven't worked in the field in a few years and sometimes goof on the details/interpretations of the code. I was mistakenly assuming my condition was an GEC, when it's in fact an EGC. So I'll be applying 250.86 rather than 250.64(E). I'm simply bonding a lighting system. Thanks again for taking the time to read/reply!