An electronically commutated motor, including: a motor body and a motor controller. The motor controller includes a control box and a circuit board disposed in the control box. The circuit board includes a microprocessor, an inverter circuit, a gear detection circuit, and a power supply. The gear detection circuit includes a plurality of current sensing units. The output end of the power supply supplies power to each circuit, and a first AC input end of the power supply is connected to a first power input line N. The gear detection circuit is connected to a plurality of gear input lines. At least one of the gear input lines is selected to be in an energized state. Each gear input line is correspondingly connected to a first input end of one of the current sensing units.