Motor Starters

[faresos]

Hello every one...

I have a situation where a motor size has changed from 30HP to 25HP.The starter size for the 30HP was specified to be size "3".The 25HP is require to have size 2. Would be any issue if we kept size 3 starter for the 25HP motor.

Thanks,

 

[sii]

The NEMA starter sizes are rated for current; the larger the number the larger the motor that can be connected to it. As long as you are going to a smaller motor you should have absolutly no issues provided that you are able to adjust the starter's overloads to the correct setting to protect the smaller motor.

Just curious, why the change to a smaller motor?

 

[faresos]

Thanks for the reply,

I was reviewing some mechanical shop drawing and they decided to go with the smaller motor (from 30HP to 25HP). I think they have determined to 25HP is large enough for this type of applications.

 

[weressl]

The NEMA starter sizes are rated for current; the larger the number the larger the motor that can be connected to it. As long as you are going to a smaller motor you should have absolutly no issues provided that you are able to adjust the starter's overloads to the correct setting to protect the smaller motor.

Just curious, why the change to a smaller motor?

not only the overload, but the instantaneous rating of the MCP, if there is any, If it is fused, then the fuse selection neds to match the smaller motor's requirement.