Phase Sequence Testing
Regulation 612.12 of BS 7671 requires the checking of phase sequence in multi-phase installations, in order to ensure that the phase sequence is maintained throughout the whole of the installation.
On the City and Guilds 2394 and City and Guilds 2395 practical assessments, the phase sequence on the 3 phase installation would affect the rotation of the motor on the motor supply circuit (motor not present on the exam).
You will be required to select the appropriate Phase Sequence tester and perform a test at the Main Switch and at the motor connections.
Both tests should indicate the same phase sequence.
Next we move on to RCD testing.
Important things to remember:
This is a live test so extra care is advised!
During the testing remember to constantly inspect the installation for faults and signs of damages.