distribution of power and protection for 4 - 30hp motors

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bedwardsnm

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I have 4 - 480VAC, 30hp motors. I am feeding a control panel from a 480V distribution panel via a 225A circuit breaker and 4/0 cable. The panel is approximately 200 feet away from the distribution panel. There will be a fuseless disconnect when the 4/0 comes into the panel. I would like to add a distribution block to reduce the multiple cables size. Then to my multiple starters which will have overloads (heaters) built on. Is the thermal overloads (heaters) sufficient protection for the wires between the distriubtion block and my starters or do I need to add fuses or a circuit breaker?
 
don_resqcapt19

don_resqcapt19

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Location
Illinois
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retired electrician
You will need a disconenct with in sight of the starters and the staters will have to have line side short circuit and ground fault protection. The maximum size of this protection for a 30 hp motor would be 100 amps if you are using an inverse time breaker.
 
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bedwardsnm

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Can this be done with a fused disconnect that will handle all motors, i.e. a 300A fuse or do I need a fuse or circuit breaker per motor?
 
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