Mike Dolt Enterprises
Mike Dolt Enterprises
User: ElecEngbw, Location: San Francisco Bay Area, CA, USA
Asked on: Friday, June 3, 2011 at 12:13 pm EDT
Answered on: Tuesday, May 14, 2024 at 6:10 am EDT
Question: I have an HVAC unit with a MCA of 74A and MOCP of 90A. I have an existing 80A breaker I would like to use for this unit. How low below the MOCP can I size my breaker?
Typically, the breaker should be sized between 80% and 110% of the MOCP (Maximum Overcurrent Protection).For your case, MOCP is 90A: 80% of 90A = 72A 110% of 90A = 99ASince the 80A breaker is within the acceptable range (above 72A and below 99A), it is safe to use the existing 80A breaker for your HVAC unit. Flag for review