What role does a selector switch play in conjunction with a voltmeter?

A selector switch is a critical component when using a voltmeter, particularly in situations where measurements across multiple phases are needed. By allowing the user to select different circuits or phases, the selector switch enables the voltmeter to measure the voltage from various sources without needing to physically disconnect and reconnect the leads each time. This functionality is essential in complex electrical systems, such as three-phase power systems, where identifying and measuring different phases is necessary for maintenance and troubleshooting purposes.

The use of a selector switch effectively streamlines the process of voltage measurement, providing an efficient way to gather data from different points in the circuit while ensuring the accuracy and reliability of the readings. This capability allows technicians to diagnose issues more effectively and maintain system integrity by making it easier to monitor multiple phases in a single operation.