An acceptable capacitance reading for a run capacitor is _____ the microfarad rating printed on the capacitor.

An acceptable capacitance reading for a run capacitor is plus or minus 10% of the microfarad rating printed on the capacitor. This tolerance is standard in the industry because capacitors are subject to variations due to manufacturing processes and the environmental conditions under which they operate.

For example, if a capacitor is rated for 10 microfarads, an acceptable reading would range from 9 microfarads to 11 microfarads. This range allows for a slight deviation while still ensuring that the capacitor functions properly within the system's specifications. Understanding this tolerance is crucial for technicians to determine whether a capacitor is functioning correctly or needs replacement.

Other options do not accurately reflect industry standards: being exactly equal would not account for normal variances, while double the value would be outside acceptable operational parameters, potentially leading to system inefficiencies or failures.