Q.I am trying to select a breaker to combine with an AC motor. What is the current value that flows through the motor?

The current that flows through an AC motor is listed in the catalog as "current (rated current)^*1". In addition, there are other types of current that flow through motors: "inrush current^*2", "instantaneous reversing current^*3", and "locked-rotor current^*4". As shown in the figure below, the value to refer to varies depending on the type of breaker being targeted.

The value of the current depends on the motor, voltage output power, so refer to the table below.

Ratio of inrush current, instantaneous reversing current, and locked-rotor current based on the current (rated current) listed in the catalog (reference value)

In order to determine the inrush current, the equation is as follows.
Induction motor, single-phase 100 VAC, 25 W: Current (rated current) 0.48 A
The inrush current is 0.48 x (3–5 times) = 1.44–2.4 A.

*1 Current (Rated current)

Current (Rated current): Rated torque, torque when rotating at rated speed.
The stabilized current of the thermal relay is set by this current value.

*2 Inrush current

This is the current that flows when the motor starts. With no load, the time for inrush current to flow is about 0.1 second. The time for the inrush current to flow will vary depending on the frictional and load inertia.
When selecting a circuit breaker or circuit protector for wiring, select a type that does not shut down with inrush current.

*3 Instantaneous Reversing current

This is the current that flows during instantaneous reversing operation of the reversible motor. The time during which instantaneous reversing current is flowing when there is no load is about 0.1 seconds.
The time for instantaneous reversing current to flow varies depending on the frictional and load inertia. When selecting a circuit breaker or circuit protector for wiring, select a type that does not shut down with instantaneous reversing current.

*4 Locked-rotor current

This is the current that flows when the shaft is locked.
When selecting a thermal relay, select a type that does not shut down at the current (rated current) = stabilized current, and shuts down at the locked-rotor current. However, if the motor is small, such as 1 W or 6 W, the thermal relay may not shut down due to the small locked-rotor current.
If you are considering protecting the motor, select a motor that is impedance protected or has a built-in thermal protector.
Click here for information about impedance protection and thermal protection.
For motors with a built-in thermal protector, use in combination with the SB50W brake pack to output a signal when the thermal protector is activated.

Refer to the following links for values of other models.

Brushless Motors Inrush Current (Reference value)
Stepper Motors Inrush Current (Reference value)
Servo Motors Inrush Current (Reference value)
Fans Inrush Current (Reference value)