The voltage to ground on a high leg or "stinger leg" in a three phase open delta system is approximately what value?

In a three-phase open delta system, the high leg, commonly referred to as the "stinger leg," has a unique voltage relationship with respect to ground. Specifically, the voltage to ground on the high leg is approximately 208 volts. This configuration arises in open delta systems where two transformers are used to create three-phase power, leading to specific voltage characteristics.

The 208 volts commonly refers to situations where the phase-to-phase voltage in such systems is 480 volts. In a three-phase system, the voltage to ground can be calculated by dividing the phase-to-phase voltage by the square root of 3 (approximately 1.732). Thus:

• From the standard 480 volts phase-to-phase voltage in such systems, dividing by the square root of 3 gives approximately 277 volts for the normal legs (the phase-to-ground voltage from the standard legs).

• For the high leg, it will be about 208 volts when viewed in relation to ground because it represents the phase with a unique higher voltage related to the neutral.

Therefore, the most accurate answer that reflects typical conditions in an open delta system regarding the voltage to ground on the high leg is 208 volts, making this the correct response.