What is a load bank primarily used for?

A load bank is primarily used to test the performance of power sources by creating a controlled load that mimics real-world conditions. This testing allows for the assessment of a generator’s ability to produce the necessary power output under various loads, which is crucial for ensuring reliability and performance in applications such as backup power systems. Load banks can provide different types of loads, such as resistive, inductive, or capacitive, enabling a comprehensive evaluation of the power source's capacity, stability, and efficiency. This testing process also helps in identifying deficiencies in generators and other power systems, ensuring that they operate reliably when needed.

Other options relate to different electrical concepts or functionalities, but do not pertain to the primary purpose of load banks, which is centered around performance evaluation. For instance, measuring motor speeds, converting AC to DC, and stabilizing voltage levels do not encompass the primary function of a load bank.