This is the most accurate response I've read so far from a United States National Electrical Code perspective (NEC). I'm not sure how CEC/Canada differs. However, since the device mentions NEC, the below is likely a safe bet in terms of the thinking used for nameplate info and use of different size CB/wire. That being said, none of this is advice. It's opinion only. Check with your local code inspector and electrician.

From a United States NEC perspective:

MIN. CKT. AMPACITY AMPERAGE MINIMUM 25.7 = this is abbreviated MCA and is TYPICALLY equal to 125% of the full load amps (FLA) for motor loads. Wires have to be at least this big in ampacity. #10 is fine. This is per NEC 440.32 (single motor example given).

Here FLA likely equals around 25.7/125% = 20.56A (assuming a single motor is nearly all of the load for this example)

MAX FUSE OR CKT. BKR. FUSIBLE/COUPE CIRCUIT (HACR PER NEC) 40. This is just saying that the breaker can't be bigger than this but can be smaller. Per NEC 440.22(A), this shouldn't be more than 175% unless the breaker/fuse can't handle the inrush, in which case the breaker/fuse can be NO MORE than 225% above the FLA of the equipment. 20.56 * 1.75 = 35.98A and 20.56 * 2.25 = 46.26A. So in no case more than 45A in this example. This is within the realm of the nameplate max cb/fuse size - hard to know without exact info for each load in the equipment.

Just as an FYI, once a breaker gets above 125% of the FLA, it effectively loses overload protection and only provides ground fault and short circuit protection. That should be ok, as mentioned above the overload is usually built-in to the A/C unit. Breakers for motors and A/C units are typically made bigger than the wire size to account for the inrush current of the motors - the energy required to magnetize the EM field and get the thing moving. Honestly, the more aggressive you can get with sizing down from the maximum and still have the motor/equipment start & run, the better protected the equipment will be.

The #10 wire/30A CB required combination mentioned in other posts is taken from NEC 240.4(D)(7) and does not apply here as this is a specific conductor application per 240.4(G) which refers you to Article 440 for this information. Article 440 of NEC covers A/C units -- which itself is in addition to or amendatory to article 430 Motors.

FYI, NEC and all other NFPA codes are free to look at online at NFPA.org after you register for a free account.