Max Breaker Size for HVAC unit - 40 amps
Min amp - 27.4 (wire size was 10 gauge)
Breaker in the panel - 30 amps
Do you make this a deal if the wire and the breaker are both sufficient for the min amp? Does this/Will this cause nusiance trips being 10 amps lower than the max amperage?
Wire size for AC condenser unit is determined by Min amp - 27.4, so, the 10 gauge wire is rated for 30 amps.
Max breaker size is exactly that, meaning you could oversize the breaker to 40amp for 30amp wire You could not do this for a typical circuit! This is allowed because the AC unit has a builtin overload protection.
Looks good…
No, it is fine.
No, it will not.
Don’t know about that… The MAX size breaker when rated higher than wire rating is permitted on motor /compressor loads to allow for the short burst of in-rush startup current and eliminate the possible nuisance tripping mentioned earlier. My report comment would mention that along with a recommendation to have this checked and serviced by a qualified electrician.
It is fine! Nothing to write up, Just move along to the next item.
Maybe Canada is different. But if it is not…
Will you pay for the service call when the electrician says it’s okay?
Thanks Larry, I typically write this up for overamperage, but have seen some templates that have breaker size lower as not sufficient. I figured the min amp had to be met with the breaker (rounded up and the wire size). Thank you for the help
You are welcome Nikki… 
That’s a good point Larry… btw, I was a licensed electrician for many years in my previous working life. My actual report comment would’ve gone on to say 'get it serviced by a qualified electrician if nuisance tripping is experienced. But to your point, if you didn’t mention it, you could still be asked to pay the service charge should the unit trip off unexpectedly.
That would be different, Joe, than what I was referring to.
Merry Christmas!
Joe, you may or may not have this information, but could you use the NEC 80% rule on the amperage to determine the minimum size breaker? If so, would that put it at a 35A breaker?
Ya, this is why I brought the question up. I just figured the 27 min amp requirement had to be met by rounding up to the 30 amp and wire gauge (10 gauge). Just didnt know what the chances of a nuisance trip happening if its 10 amps lower than the max amperage breaker that could be installed
Sorry Brian but I’m not familiar with the NEC rulings. Up here, the 80% rule is applied to ‘continuous vs non-continuous loads’, typically for wire or breaker sizing on lighting or heating loads.
Depending on type of motor loads involved, overcurrent protection could be 200 to 250% of full load (nameplate) amps. In this case where the AC nameplate shows a max of 40 amps, that should not be exceeded. Of course it may run fine at 30 amps for years, on the other hand, as time passes and the breaker ages or gets tired from running at it’s higher levels over time, it can weaken and start tripping at startup. Then it’s one of those things where if you said nothing, your client may say their electrician claims you should have told them the breaker was (pick one) undersized or fine as it is at 30 amps. That’s why I’d enter the comment to have it serviced by a qualified electrician IF bothersome, as only an electrician is supposedly ‘qualified’ to observe the startup through a clamp-on amp meter and understand what’s happening.
Sorry for the long reply but hope it helps
No need to do any math. Just follow the information from the data plate.
Smaller breakers may installed but may trip. If so install a larger breaker up to the maximum allowed.
Yes, thanks!
I agree. Move on.
The answer is right there in front of you. 30 is more than 27.4 (the minimum) and less than 40 (the maximum). Put another way, 30 is between the minimum and the maximum. It is within the specified range.
Huh? 
-————
Your customer should demand a refund from you and send you the bill for the electrician’s wasted service call.
Wow, that’s a little harsh, especially coming from someone who feels the need to tout all his electrical qualifications, yet your reasoning or response to Nikki leaves me wondering.
Sure it could run fine for many years being fused at full-load amps, but in your electrical contractor years, have you not seen startup amps trip circuits?
Since starting home inspections in ’97, I’ve never had (knock on wood) anyone come asking for a refund of inspection fees or contractor service charges. Nikki brought up a good question and I’m not one to call for 3rd party experts to rush in, but I do think it’s all in the presentation and how you report details.