What causes an amp drop on the motor of a vacuum system?

A blocked inlet in a vacuum system can lead to an amp drop on the motor due to the restriction of airflow. When the inlet is obstructed, the motor has to work harder to create the necessary suction, which can cause it to draw fewer amps than it normally would. This phenomenon occurs because the system reaches a state of reduced efficiency; the motor may not be able to maintain its designed operating conditions. In essence, while the motor is running, the inability to move air efficiently through a blocked inlet can lead to a reduction in the current drawn, resulting in an amp drop.

In contrast, a blocked outlet or an open filter would typically lead to increased resistance and could potentially cause the motor to draw more current due to increased load, which is the opposite of an amp drop. A clean filter allows for optimal airflow, maintaining the motor's amperage at expected levels. Each of these factors affects how the motor operates under different conditions, but a blocked inlet is the specific cause tied directly to an observed amp drop.