Which situation causes an increase in current to the motor?

The scenario where the fan compartment door is removed can lead to an increase in current to the motor due to a reduction in the back pressure or resistance against which the motor has to work. When the door is removed, the system airflow may become unrestricted, potentially altering the load conditions for the motor.

In a typical motor-driven fan application, the motor operates against a certain load, which is defined by the static pressure of the system. If there is an alteration in airflow that allows for easier operation, unexpected changes can occur. However, removing the compartment door could also result in changes that may not necessarily equate to an increase in the motor’s load in a traditional sense, but if this scenario leads to an imbalance or an unexpected configuration, it can cause the motor to draw more current momentarily as it adjusts to the new operating conditions.

Installing or keeping the fan compartment door on would typically stabilize the airflow and ensure the motor operates within its expected parameters with a defined load. Also, increased mechanical resistance generally leads to an increase in required current because the motor has to work harder to overcome friction or other forms of mechanical resistance. Placing the motor under load will directly lead to an increase in current because the motor has to supply more power to handle the