Medium Blower Speeds

When the Medium 1 blower (2) speed is selected, the HVAC control assembly applies voltage to the blower motor switch assembly through the off blower motor control circuit. The blower motor switch will direct the voltage through the medium 1 blower motor control circuit. Voltage is divided between 2 series resistors in the blower motor resistor assembly.

Voltage is supplied from the blower motor resistor assembly to the blower motor relay on the blower motor supply voltage circuit, then to the blower motor to achieve the desired blower speed. The blower motor is included in the series circuit by the blower motor supply voltage and ground circuits. The ground circuit provides a ground path for the blower motor.

When the Medium 2 blower (3) speed is selected, the HVAC control assembly applies voltage to the blower motor switch assembly through the off blower motor control circuit. The blower motor switch will direct the voltage through the medium 2 blower motor control circuit. Voltage is divided by a single resistor in the blower motor resistor assembly. Voltage is supplied from the blower motor resistor assembly to the blower motor relay on the blower motor supply voltage circuit, then to the blower motor to achieve the desired blower speed. The blower motor is included in the series circuit by the blower motor supply voltage and ground circuits. The ground circuit provides a ground path for the blower motor.