A High-leg delta service is also known as Wild-leg Delta or Red-leg Delta.
This type of delta service provides a center-tap of one of the delta windings that is the grounded neutral. This is used to provide a small amount of 120/240V split-phase power from a transformer where the majority of the loads are 240V 3-phase delta (no neutral). The "high leg" is the non-center tapped phase, which must not be reference to the center tapped neutral, as its voltage will be 208V to that neutral. that is why it is marked with a distinctive color, usually orange.
The existence of High-leg Delta is the reason for measuring every service before connecting equipment to it.
When faced with a high-leg delta service, the entertainment electrician must regard it as a 120/240V single-phase service, and must ignore the high leg.
This type of delta service provides a center-tap of one of the delta windings that is the grounded neutral. This is used to provide a small amount of 120/240V split-phase power from a transformer where the majority of the loads are 240V 3-phase delta (no neutral). The "high leg" is the non-center tapped phase, which must not be reference to the center tapped neutral, as its voltage will be 208V to that neutral. that is why it is marked with a distinctive color, usually orange.
The existence of High-leg Delta is the reason for measuring every service before connecting equipment to it.
When faced with a high-leg delta service, the entertainment electrician must regard it as a 120/240V single-phase service, and must ignore the high leg.
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