What is the allowable voltage variation for a residence with a 120 volt secondary service?

The allowable voltage variation for a residence with a 120-volt secondary service is typically defined to include a range that ensures appliances and devices work effectively without risk of damage due to voltage fluctuations. The correct range reflects the necessary tolerance that regulatory standards and utility guidelines aim to maintain for safety and efficiency.

In this case, the correct answer outlines a range of 114 to 126 volts. This range is optimal as it provides a healthy buffer above and below the nominal voltage of 120 volts. Voltages falling within this range ensure that electrical devices function properly without undue stress or risk of malfunction.

For reference, a significant deviation outside this range might impact the performance of electrical systems and appliances, leading to potential damage or failure. The other options, while closer to the standard, do not provide the same safety margin around the nominal voltage, thus making them less suitable.