text: This is for service voltage...\n\nFor any specific nominal voltage, the operating voltages on a power system will differ from that nominal value due to voltage drop in the system as well as changes in the system’s operating condition. It is important that the design and operation of power systems and accompanying utilization equipment be coordinated with respect to these voltage variations so that the performance of customer equipment will be satisfactory throughout a range of the actual voltages encountered on the system.\n\n\nVoltage is divided into two ranges: A and B. Each voltage range is listed for two locations: service and utilization. Service voltage is measured at the point of delivery; utilization voltage is measured at the terminals of the utilizing equipment.\n\nYou know lot's of electrical devices have different voltage ranges in power systems such as transformers and in power electronics like convertors and sensors... so it actually depends on the specific type of voltage range you ask for..