Acceptable power factor values are determined by comparing current test results to what?

The correct answer lies in the principle of evaluating the effectiveness of electrical equipment over time. Acceptable power factor values are assessed by comparing current test results to previous test results. This approach allows for a historical analysis, enabling maintenance personnel to identify changes in power factor that may indicate potential issues with the equipment. By examining trends over time, technicians can determine whether the power factor is maintaining a stable performance, improving, or declining.

This comparison is crucial because it helps in recognizing patterns that can inform maintenance decisions. If the current results deviate significantly from the historical data, it may signal that the equipment needs further investigation or maintenance. This method of looking back at previous performances ensures that operators maintain reliability and efficiency in substation operations.

While industry standards, future predictions, and manufacturer specifications provide helpful benchmarks and guidelines, they do not reflect the direct operational history and performance of specific equipment. Therefore, relying on past test results is a more effective way to gauge the current state and operational efficiency of electrical systems.