Wiring error prevention device and method for single-phase AC three-speed motor

The invention provides a wiring error prevention device and method for a single-phase AC three-speed motor. The device comprises a motor terminal block, a temperature controller terminal block, a first relay, a second relay and a third relay, wherein the motor terminal block is connected with the single-phase AC three-speed motor; the temperature controller terminal block is connected with an external single-phase AC power supply through a temperature controller; the first relay, the second relay and the third relay constitute a protective logic loop and are connected between the motor terminal block and the temperature controller terminal block; where a wiring error occurs, the protective logic loop can disconnect all the first relay, the second relay and the third relay, thereby avoiding motor erroneous operation which causes rise of voltage and damages the single-phase AC three-speed motor.The device can be used for protecting the motor and preventing the motor from being burnt out in the case of a wiring error. The device not only can be applied to the fan-coil unit of a central air conditioner but also can be widely used for wiring error prevention for the single-phase AC three-speed motor.