Sizing MCP

[LRB]

Good evening
We are installing 20 HP roller feed mill. We have GE 6000 series MCC with spare bucket with MCP and starter sized for 3 HP blower which is not used. I would like to retofit the bucket for 20 HP motor...FLA 27 at 460 V. I know I will need NEMA Size 2 starter with thermal O/L relay. DO not desire electronic O/L relay. I think the MCP I need is GE TEC36030. This this MCP is rated for 30 amp continuious and adj. mag trip of 90-360 amp. Am I correct?

 

[petersonra]

Good evening
We are installing 20 HP roller feed mill. We have GE 6000 series MCC with spare bucket with MCP and starter sized for 3 HP blower which is not used. I would like to retofit the bucket for 20 HP motor...FLA 27 at 460 V. I know I will need NEMA Size 2 starter with thermal O/L relay. DO not desire electronic O/L relay. I think the MCP I need is GE TEC36030. This this MCP is rated for 30 amp continuious and adj. mag trip of 90-360 amp. Am I correct?

It sounds Ok to me but I am not going to look up the specs for you.

You will need to make sure the MCP, overload, and motor starter are listed to be used in combination.

I have found it is often more cost effective to buy a whole new bucket rather than to buy the parts.

 

[Jraef]

It sounds Ok to me but I am not going to look up the specs for you.

You will need to make sure the MCP, overload, and motor starter are listed to be used in combination.

I have found it is often more cost effective to buy a whole new bucket rather than to buy the parts.

+1
The only thing you are saving on is the steel frame and stab assembly, and even then you are trusting that there is nothing wrong with the old stab assembly. MCPs as new parts are expensive, because there is no legal use for them other than direct replacement of existing units. So since you must change the contactor and OL anyway, the sum of those parts will likely cost more than the new bucket.

You are also violating the UL listing of that bucket by changing it on your own. That might not matter from an AHJ standpoint because it's not going to be inspected, but if you make any mistake that leads to a fire, and an insurance investigator notices that, having voided the UL listing may be an issue they use to get out of paying for the damage. Remember, UL stands for Underwriters Laboratories, as in INSURANCE underwriters.