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NEC information about motors

Question asked by cclabbers on Nov 2, 2020
Latest reply on Nov 10, 2020 by brianbaughman

I have had a 300hp motor shipped to me with the motor opening being to small for the amout of leads that are coming out. So small infact that the motor leads insulation was being cut by the conduit adapter on the motor outlet cover. This adapter is a 2.5 inch adapter welded to the motor cover. There are 12) 1/0 motor leads and 1) 4/0 ground. If going by NEC standards for conductors and conduit, the conduit should be 4 inch. This would mean I would have to have an opening of 4 inch too, not the 2.5 inch causing a restriction of the wires. 

They were crammed in so tight that they were having a issue with the high pot testing.  There is also no way of pulling all the leads through a piece of 2.5 inch conduit. 

Do motors have an exemption that they don't need to follow the NEC code for conductors and opening size. There has to be a standard of some sort so that the leads insulation doesn't get cut. I would also figure that there would also be a UL standard that would not alow this kind of thing happening. 

If there is any information anywhere that would be helpful, please let me know. I have been combining over the NEC book and have not fou d any exemptions.  I need to let our engineers know something.