NATE Air Conditioning and Heat Pumps Practice Exam

To determine the safe operating current of a 24-V transformer with a 40-VA rating, you can use the formula that relates power (in volt-amperes), voltage, and current. The formula is given by:

Power (VA) = Voltage (V) × Current (A)

Rearranging this formula to find the current gives:

Current (A) = Power (VA) / Voltage (V)

Substituting in the provided values:

Current (A) = 40 VA / 24 V ≈ 1.67 A

This calculation indicates that the transformer can safely operate at a current of approximately 1.67 A without exceeding its 40-VA power rating. This means the transformer can handle the flow of current up to that value without risk of overheating or damage, making it essential for the system's reliability and performance.

Understanding this relationship between voltage, current, and power is crucial in working with transformers and ensuring that they operate within their specified limits to prevent failures in air conditioning and heat pump systems.