How can you identify the phase of electrical supply?

Identifying the phase of electrical supply is critical for ensuring proper connections and avoiding potential mishaps in electrical systems. Using a phase sequence meter is the most effective method for this task. This specialized instrument is designed to measure and display the phase rotation of three-phase electrical systems, providing valuable information about the sequence in which the phases are energized.

The phase sequence is important in applications where the direction of rotation of motors and other three-phase equipment must be consistent. A phase sequence meter will indicate whether the phases are in the correct order, helping technicians avoid problems that could arise from incorrect phase alignment.

In contrast, measuring the voltage across phases can provide some information about the system but does not directly indicate the phase sequence. While checking a circuit diagram can offer insights into how the system is wired, it does not provide real-time verification of the phase sequence. Furthermore, using a continuity tester is primarily for checking the integrity of the connections rather than determining phase relationships, making it unsuitable for this specific need.

Thus, the use of a phase sequence meter stands out as the most appropriate and reliable method for identifying the phase of electrical supply in a three-phase system.