How will an extremely dirty air filter affect the amp draw of a PSC centrifugal blower motor?

An extremely dirty air filter creates increased resistance to airflow in a HVAC system. This restriction means the blower motor has to work harder to pull air through the filter, which can lead to an increase in the load on the motor. As a result, the motor may draw more current to maintain the required airflow.

However, the option chosen suggests that the motor current will decrease because the fan will be moving less air, which doesn't accurately reflect the scenario. Although the air movement may be restricted, the blower motor experiences an increased load and typically results in higher amp draw rather than a decrease. The increased resistance from the dirty filter can cause the motor to consume more electricity as it struggles to overcome this resistance.

Choosing the correct answer involves understanding the relationship between airflow resistance, motor load, and current draw, highlighting that the airflow limitation actually leads to increased current draw rather than a decrease.