timm333
Senior Member
- Location
- Minneapolis, MN
- Occupation
- Electrical Design Engineer
Can the ampere rating of disconnect (and MCC) bus be less than the ampere rating of fuse, if yes, which NEC rules allows it? Thanks
disconnect switch rating
- Thread starter timm333
- Start date
- Status
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
430.110 states the disconnect must be no less than 115% of the FLA of the motor. So yes it can be less than the ocpd
timm333
Senior Member
- Location
- Minneapolis, MN
- Occupation
- Electrical Design Engineer
So can the contactor also be sized smaller than fuse as long as the contactor is sized for 115%? I think it can be, just making sure.
Also the transformer also has inrush current like motor, then why is it that the disconnect of transformer is sized for only 100% (instead of 115%).
Also the transformer also has inrush current like motor, then why is it that the disconnect of transformer is sized for only 100% (instead of 115%).
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