Motor terminal box bonding jumper

[thinker]

It is, probably, quite simple question, yet causing a lot of confusion. We have a motor terminal box with removable and gasketed top, bottom and side panels. These panels must be bonded to the main ground bar of the motor (located inside the box). Motor will be fed by 4 wires size AWG # 4/0 per phase in parallel, the equivalent size of the equipment grounding conductor (sum of cross-sectional areas of separate grounding conductors) is AWG # 2/0. This is in compliance with NEC table 250-66.
The question is: what should be the size of bonding conductors for the above removable panels? Could we use smaller than 2/0 conductors to equilize panel potentials with the ground potential for safety?

 

[7anoter4]

According to NEC art.250.122 "Size of Equipment Grounding Conductors" (D) Motor circuits - the equipment grounding connection conductor shall be not less than indicated in Table 250.122 for (Not Exceeding) the Rating or Setting of Automatic Overcurrent Device in Circuit Ahead of Equipment, Conduit etc.,

 

[REDDOG]

How is the motor junction box connected to the motor frame?

 

[thinker]

Reddog, the j-box frame is bolted to the motor frame threaded holes in 4 places, contacting metal surfaces are clean of paint, degreased and use a conductive compaund, there are also connections via threads/bolts.