There is a property that has a 30-amp breaker in the electrical distribution panel labled for the AC unit. The outside HVAC unit had a maximum over-current protection rating of 25-amps. I'm looking to see how serious this is and also to understand why the breaker doesn't trip with that amp difference.

Thanks.

Flickit

...won't trip until its limit is exceeded by some percentage. You are quoting the nameplate of the A/C unit and what it should be fused at (25A). The breaker in the panel is oversized at 30A.

mbridges

Thank you for your response. I see what your saying about the percentage
but could you explain about the breaker in the panel being oversized and
could that cause any problems.

Flickit

...indicates a 25A rating this is to describe to the installer that no larger rating than a 25A breaker should be used as a disconnect and a resettable fuse for the A/C. As you have a 30A breaker, this is larger than the nameplate indicates and should be changed out to a 25A breaker for reasons of safety.