other customers who have both single-phase lighting and three-phase motor loads. The bank wiring is similar to that of the Three-phase, 3-wire Delta banks shown in the prior examples. The exception is the right transformer is excluded and the left transformer in this diagram is grounded at its center tap which is also connected to the service neutral to form a 4-wire service. Voltage ratings for this type of bank may be 240∆/120 or 480∆/240 . As mentioned previously, 240∆/120 are very common where a mix of 120/240 3-wire single-phase loads are present along with 240∆ three -phase loads. 480∆/240 service is used for agricultural irrigation as well as oil-field and other industrial motor load. As with other 4-wire Delta services, the c-phase of the secondary is √ 3 times higher to neutral than the other two secondary phases to neutral. This c- phase is commonly called “wild leg,” “power leg,” “stinger leg,” “high leg,” and “crazy leg,” but they are all referring to the same service conductor.
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