HVAC RTU existing breaker size?

[HipHopHead]

RTU is being fed by 3 pole 70.
Maximum breaker/fuse is 50.
MCA is 41
I used a fused disco w/ 3 - 50 amp fuses
Can someone refresh my brain, to the article that tells me what that breaker should be sized at?

Thanks in advance

 

[augie47]

Take a look at this recent thread:

AC unit feeder and branch circuits NEC 430

This subject has been beat almost to death before, but there is one distinction I would like everyone's opinion on. There is a 12AWG Romex, running 240V (on black and white conductors) from the inside load distribution center on a two pole 30A breaker, feeding the required outside...

forums.mikeholt.com

 

[infinity]

Can someone refresh my brain, to the article that tells me what that breaker should be sized at?

What size are the existing conductors?

 

[HipHopHead]

#4 cu

 

[augie47]

With #4 cu you could use anything up to a 90 amp breaker. Your havc is protected by the disconnect so all you are protecting is the #4 feeder/ branch circuit

 

[HipHopHead]

Thanks for the link. Great conversation. In other words Im not required to do anything to the breaker, due to the fused disconnect providing the OCP, as long as it properly sized for the conductor.

 

[infinity]

Thanks for the link. Great conversation. In other words Im not required to do anything to the breaker, due to the fused disconnect providing the OCP, as long as it properly sized for the conductor.

Yup. The existing 70 amp OCPD is protecting the 90 amp feeder conductors.