EMT as Supply side bonding jumper?

[jibron]

So we're hooking up a 225KVA stepup xfmr. 208 delta to 480wye. I've seen articles stating that for the supply side bonding jumper we can simply use the 2" EMT conduit running from the xfmr to the first (service) disconnect with grounding bushings on each end. This just doesn't seem right and seems to conflict with other articles I've read but I'll admit it was in older handbooks. 2020 is on order.
Any clarifications would be appreciated. Unfortunately we already have the wire in the pipe. 4 x 4/0 and it was a b#@$h to pull but it was a tight run and 2 1/2" wouldn't have worked.

 

[infinity]

So we're hooking up a 225KVA stepup xfmr. 208 delta to 480wye. I've seen articles stating that for the supply side bonding jumper we can simply use the 2" EMT conduit running from the xfmr to the first (service) disconnect with grounding bushings on each end.

Is this actually a service?

 

[jibron]

Is this actually a service?

It is a separately derived system. The building is served by 600A, 208/3 phase, 4 wire. The transformer is fed from a tap box by two parallel 350mcm runs. the transformer will feed a 480 panel with a 225A MCB (service disconnect).

 

[infinity]

So it is not a service disconnect. Then no bonding bushings or a wire type SSBJ are required. The EMT between the transformer secondary and the MCB can serve as the SSBJ. It's questionable if a #2 SSBJ would even fit in that 2" EMT with the #4/0's.