mbrooke
Batteries Included
- Location
- United States
- Occupation
- Technician
Is there anything in the code that allows for an OCPD to be larger than the conductors feeding an MCC?
Would 240.4(B)(1)-(3) fit your installation?Is there anything in the code that allows for an OCPD to be larger than the conductors feeding an MCC?
Would 240.4(B)(1)-(3) fit your installation?
Take a look at Part V of Article 430, but it appears to me that the application of 430.62(A) will actually require conductors with an ampacity greater than the rating of the OCPD for many MCCs. It will change based on the actual combination of motors fed from the MCC.
All of the ones I installed have just had the conductors sized like any other feeder, that is the conductor ampacity is equal to or greater than the OCPD rating.
I don't think that makes any difference for most motor loads...the conductors are all required to be sized at 125% of the motor full load current as found in the Article 430 tables.FWIW, all the motors are continuously run for more than 3 hours many 24/7.
I don't think that makes any difference for most motor loads...the conductors are all required to be sized at 125% of the motor full load current as found in the Article 430 tables.
It is sized at 250% of the largest motor plus the sum of the full load currents of all of the other motors.Right, but the NEC doesn't let the MCC feeder OCPD be sized at 250%.
Right, but the NEC doesn't let the MCC feeder OCPD be sized at 250%.
Is there anything in the code that allows for an OCPD to be larger than the conductors feeding an MCC?