Wiring a motor - can't fit everything in 2.5" conduit. Is there any other way?

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Use the IMC as your EGC. At the motor, use LTFMC, and get the connectors that have the external bonding lugs, and run 4 AWG. T&B makes these connectors. I had a 50 hp motor wired in 1" RMC with 3 4AWG THN, which was never going to come out as it went waaay in the back of an MCC. So I used the T&B LTFMC connectors with an external bond wire (max 6 ft). There is a picture of this install in Mike Holts Grounding and Bonding text. Later I can post a picture.
 
Twophase said:
Not sure if it matters, but this is fire pump territory, so there is no thermal protection. Controller has magnetic only breakers.
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Oh that changes everything. My experience with fire pumps is you can't change anything with out listing issues. They are painted red and cost a lot more.
 
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Here's my issue:
Twophase said:
I'm coming directly from a transformer (transformer to controller to motor).
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Downstream of a transformer, you have to hit an overcurrent device before you hit a load (i.e., your motor). Most often, the transformer powers a panel with a main breaker, and loads are fed from that panel. If you don't have a panel, then you need a fused disconnect, an enclosed circuit breaker, or some other overcurrent device between the transformer and the controller. The N-G bond will be made at that device. From that device going upstream to the transformer, the "ground-thingy" is a Supply Side Bonding Jumper, sized per 250.102(C). You run a GEC, sized per 250.66, from the neutral point to planet Earth. From the ground point to any downstream load, you run an EGC, sized per 250.122.
 
What is the horsepower and voltage of the motor? 275 amps does not appear in any of the full load motor current tables. In general, the values in those tables, and not the nameplate current must be used for sizing the conductors.
 
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