Conduit Bonding Question

[exranger06]

I'm installing a subpanel in my garage. I'm going to run 2-2-2-4 MHF aluminum cable to feed my 90 amp subpanel. I'm using 1.5" RMC (yes, I know it's overkill for this application) to go down the wall from the main panel to underground. Once it's underground, I'm going to transition to direct bury. Then I'll have RMC again where it emerges from the ground and connect to the subpanel. My question is, do I need to use bonding bushings inside the panels and if so, what size wire do I use to bond? I plan on using plastic bushings on the buried ends of the conduit. Wire will be buried at least 24" deep. Is there anything else I need to know or do, or does this sound good?

 

[sberry]

Are there eccentric / concentric knockouts or is this the largest or a drilled hole?
It's been so long since I use pipe like that I forget, might be 6 for 100 , seems it is 4 for 200 but that's just a wag.

 

[exranger06]

Are there eccentric / concentric knockouts or is this the largest or a drilled hole?
It's been so long since I use pipe like that I forget, might be 6 for 100 , seems it is 4 for 200 but that's just a wag.

Concentric knockouts. I'm using a reducing washer in the main panel.

 

[wyliesdiesels]

Bonding bushings only required on 480v.

 

[sberry]

Wylie would know so defer to him for accurate answers but similar to a pipe mast you want to make sure it's grounded/bonded to the can. The point being is that there is a method for short circuit interuption in case of a fault. I wouldn't lose sleep over it if it was well fastened. Some way the KO can't get broken and the pipe becomes detatched.
The bond Bush is screwed to the pipe thread and then hooked with wire to the ground bar, it's basically insurance, adding suspenders to the belt for lack of better wording.