Please help. I need some clarification on breaker types and what the NEC requires with regard to breakers. Specifically, I'm working with lighting circuits, so they are simply 120v or 277v applications at 20 amps.
Manufacturers of lighting control equipment (relay and dimming panels) can provide equipment that is configured as a Main breaker or MLO with branch circuit breakers to provide protection of the branch circuits. Some manufacturers provide breakers that are "fully magnetic" and other manufacturers provide circuit breakers that are "thermal magnetic". These panels are being used as distribution panels and there is no other protective devices on the branch circuits.
My understanding is that thermal magnetic breakers provide instantaneous as well as over current protection. It is also my understanding that the fully magnetic breakers do not provide overcurrent protection. Please correct me if this is not accurate. I would think that the NEC would require branch circuits to be protected for both instantaneous and overcurrent conditions. I'm having difficulty determining the code's requirements in regard to this.
In a nutshell, my question is this.... If a distribution panel uses fully magnetic breakers, does it meet the minimum requirements of the NEC for branch circuit protection???
Many thanks for your thoughts and input.
Regards,
Skiff
Manufacturers of lighting control equipment (relay and dimming panels) can provide equipment that is configured as a Main breaker or MLO with branch circuit breakers to provide protection of the branch circuits. Some manufacturers provide breakers that are "fully magnetic" and other manufacturers provide circuit breakers that are "thermal magnetic". These panels are being used as distribution panels and there is no other protective devices on the branch circuits.
My understanding is that thermal magnetic breakers provide instantaneous as well as over current protection. It is also my understanding that the fully magnetic breakers do not provide overcurrent protection. Please correct me if this is not accurate. I would think that the NEC would require branch circuits to be protected for both instantaneous and overcurrent conditions. I'm having difficulty determining the code's requirements in regard to this.
In a nutshell, my question is this.... If a distribution panel uses fully magnetic breakers, does it meet the minimum requirements of the NEC for branch circuit protection???
Many thanks for your thoughts and input.
Regards,
Skiff