Need help with a small issue related to an electrical appliance

That’s roughly what it means: the value must be higher than the rated current of the circuit. By how much? 1.2 times. But you need to check whether 1.2 times is sufficient for your needs. For example, if the rated current is 40A, then you have to choose a circuit breaker with a rating of 60A; a 50A one would work as well, but is such a option available?

When selecting an air switch, it is generally sufficient to choose one with a rating that is 1.2 times the current required by the electrical appliance. For example, at a voltage of 220V, if a particular appliance has a power rating of 5000W, the current required is around 23A. Multiplying 23A by 1.2 gives 27.6A; therefore, a standard 32A circuit breaker would be suitable. Air switches have two important technical parameters: trip current (Im) and rated current (In). The tripping current is the maximum current at which a circuit breaker will trip; in other words, it is the current level at which the circuit breaker operates to provide protection when an overload or short circuit occurs in the distribution circuit. To perform short-circuit current calculations, it is generally necessary to avoid the short-circuit current under the maximum operating condition at the beginning of the line. The rated current refers to the current that an air switch can carry over a long period of time; as long as the actual current in the circuit does not exceed this value, the device can operate continuously. In practical applications, to protect the power supply lines, the tripping current of the air circuit breaker used must be less than the maximum current that the power supply lines can handle. Meanwhile, its rated current should be equal to or slightly greater than the maximum normal operating current of the distribution lines. Complex air switches offer four types of protection: instantaneous trip, short-time delay trip, long-time delay trip, and single-phase ground fault trip.