There are several reasons why a defective blower motor draws more current than a good motor:
1. Winding Defects: A defective blower motor may have issues in its windings. These windings are made of copper wires that are responsible for generating a magnetic field when an electric current flows through them. If there are any breaks or short circuits in the windings due to wear and tear, insulation damage, or manufacturing defects, the motor will draw excess current to compensate for the reduced efficiency.
2. Increased Resistance: Defects in the blower motor can lead to increased resistance in the windings. This higher resistance restricts the flow of electric current, causing the motor to work harder to maintain its speed. As a result, the current draw increases to overcome the increased resistance.
3. Mechanical Issues: If there are any mechanical problems, such as misalignment of parts, bearing damage, or debris blocking the motor's airflow, it can hinder its smooth operation. The motor will have to work harder to overcome these mechanical obstacles, resulting in higher current consumption.
4. Starting Capacitor Failure: In the case of an AC induction blower motor, a starting capacitor is used to provide the initial boost of torque required to start the motor. If this capacitor fails or becomes defective, it can cause the motor to draw more current during the starting phase.
It is important to note that the specific reason behind increased current draw in a defective blower motor can vary depending on the type of motor and the nature of the defect. Therefore, proper diagnosis and troubleshooting are necessary to identify and rectify the underlying issue.
