I have an MCC bucket with a 100A breaker & size 3 starter. I have a temporary piece of equipment with MOCP of 80A. Would like to use the existing bucket. Can I size the conductor from MCC to fused disconnect to the equipment MCA with a fused disconnect & 80A fuses located at equipment? Or do I need 100A cable from MCC to fused disc?
Motor protection/wire size
- Thread starter bcbeaver
- Start date
- Location
- Illinois
- Occupation
- retired electrician
First is the OCPD in the MCC bucket an actual breaker? Many are motor circuit protectors and you can't use them for supplying other loads.
If it is a breaker, you will have to use 100 amp conductors unless you can use one of the tap rules in 240.21(B). The tap rules may permit the use of 80 amp wire from the breaker to the fused disconnect.
If it is a breaker, you will have to use 100 amp conductors unless you can use one of the tap rules in 240.21(B). The tap rules may permit the use of 80 amp wire from the breaker to the fused disconnect.
Eddie702
Licensed Electrician
- Location
- Western Massachusetts
- Occupation
- Electrician
It must be a thermal magnetic breaker not a MOCP (motor overcurrent protector). If it is a breaker you can use conductors that comply with the motors MCA must terminate in an 80 amp breaker or fuse and the length of the tap from MCC to the switch or breaker must comply with the tap rules.