High Leg Deltum Wiring Diagram
Double delta connections always provide 240 120v single phase t3.
High leg deltum wiring diagram. It s important to note that the line current from a delta transformer doesn t equal the phase current. 10 and 12 lead high wye available voltages 10 lead generators are identical to 12 lead generators with the exception that t10. Many call it a high leg system because the voltage from line 2 to ground is higher than that of the other legs. If the secondary is a four wire delta the fourth wire originating at a center tap on one of the legs of the delta is grounded.
For example a 120v delta transformer will have a 208v leg. It is used when both single and three phase power is desired to be supplied from a three phase transformer or transformer bank. Hook up a high leg to a single phase 120 volt piece of equipment and wait for the power supply to blow up. We are adding a new 150 amp 208y 120v panel board for the it server ups and hvac.
Hello i am working on a project at a local hospital. Figure 10 illustrates the wye delta connection either as three single phase transformers or as a single three phase unit. The nec code requires that the high leg be identified by an orange color it was often referred to as a red leg delta or by other effective means and is usually the b phase. Both bushing labels and polarity dots are shown.
3 phase delta power. U n w w2 w6 v6 w1 v2 w5 u1 u2 u5 u6 v1 v v 240v 12 lead double delta. Panelboards since 1975 panelboards supplied by a 4 wire delta connected 3 phase system must have the high leg conductor terminate to the b phase of a panelboard 408 3. High leg delta also known as wild leg stinger leg bastard leg high leg orange leg red leg dog leg delta is a type of electrical service connection for three phase electric power installations.
The primary wye windings are typically grounded. The utility service is 240 120 3 phase 4 wire high leg and the emergency generator is 208y 120 3 phase 4wire 208v line to line and 120v line to neutral. In this example the line current is 87a and the phase.