This video discusses a 120/240V Three-Phase Four-Wire Delta System. Although uncommon you may still find these systems in existence.
The B phase is center-tapped and grounded to provide more available voltages. Voltage from Line A to Ground is known as the high-leg.
The code rules referenced in the 2018 Canadian Electrical Code are 4-032 4) and 5)
3-Phase Delta Connections Playlist: [ Ссылка ]
0:00 Intro
2:16 Phasor Diagram
4:34 High-Leg Voltage
6:07 Installation Considerations and Rules
#Delta #4wire #grounded
