Certified Apartment Maintenance Technician (CAMT) Practice Exam 2025 - Free CAMT Practice Questions and Study Guide

The two most common types of fan drives for blowers in air conditioning systems are the permanent split capacitor (PSC) and electronically commuted motors (ECMs).

Permanent split capacitor motors are favored in many applications due to their efficiency and simplicity. They utilize a capacitor to create a phase shift in the current, which allows the motor to start and run more smoothly, minimizing energy loss. This type of motor is particularly effective for blower applications in HVAC systems, where consistent speed and reliability are crucial for maintaining comfortable indoor environments.

Electronically commuted motors, on the other hand, offer advanced energy efficiency and control. They employ electronic circuits to eliminate the mechanical commutator found in traditional motors, allowing for precise speed control and improved performance. ECMs adapt their speed based on demand, making them highly efficient and versatile, especially in variable airflow applications typical in modern air conditioning systems.

Considering these attributes, the selection of PSC and ECMs highlights the industry's trend toward energy efficiency and performance optimization in HVAC systems. In contrast, the other options present motors that, while they have their own applications, are less representative of the standard practices in air conditioning systems today.