Air conditioning overcurrent protective devices can never exceed what percentage of the motor-rated load current or branch circuit selection current?

The correct answer is the maximum value that overcurrent protective devices for air conditioning systems should not exceed, which is set at 225% of the motor-rated load current or the branch circuit selection current. This standard is established primarily for protecting the motor during start-up conditions, when inrush currents can significantly exceed normal operational levels.

By allowing a higher percentage of the rated load current, the overcurrent protective device can accommodate these high start-up currents without tripping unnecessarily, ensuring that the air conditioning system operates efficiently during initial activation. However, the limit prevents excessive current from damaging the circuitry or components over prolonged periods, as higher percentages could lead to premature failure of the motor or other electrical components.

This understanding is crucial for both safe installation practices and compliance with electrical codes that govern the operation of HVAC systems. Hence, 225% serves as a balanced threshold that protects both the longevity of the equipment and the safety of the electrical system.