I have a 100 amp breaker feeding a 60 amp sub panel on a rooftop. Would that sub panel need a main breaker or a disconnect?
Anybody respond on here? I told the people installing that it needs a disconect. I'm I right? Figure anything on the roof has to have a disconect within 25'
Code violation; Where is the overcurrent protection for the 60 ampere panel bus rating? The feeder needs to be protected not greater than the panel bus rating or the feeder conductors which ever has the lower ampere rating.
This thread is two years old and it only now shows up.
I will presume that your project is long past viewing even through your rear view mirror. So if you would like we could use this one for next time.
The way I understand your question is that the rooftop subpanel is only rated for 60 amps. That is not very common. The vast majority of panelboards have at least a 125 amp rated bus. There are some two-space breaker enclosures rated for 60 amps and 70 amps though.
Since the panelboard is located on the roof top, I have to wonder if the loads are roof top units. That would alter the correct answer greatly. So first we must know what loads are served.
So you have a 100-amp breaker feeding a subpanel on the rooftop.
We need to know what loads are served and what protects each one.
That includes what each appliance's nameplate says about minimum ampacity and maximum OCPD.
What size of conductors connect each load to the subpanel.
What size of conductors connect the subpanel back to the breaker.
No, the subpanel does not necessarily require a main breaker.
Maybe the wire is big enough, may it is not.
Maybe the subpanel bus is big enough, may it is not.
If you still want to work through it, post the specific details of the installation.
Retrieving data ...