Useful tips

Can you ground a Delta transformer?

Can you ground a Delta transformer?

Many existing systems are delta connected and therefore these source transformers have no neutral available for grounding. However, this neutral point can be obtained by applying a zig-zag grounding transformer to the system. The center-tap-grounded delta, however, is frequently used on 240-V four-wire systems.

What is the voltage to ground in a 480V Delta?

The phase to ground voltage on a 480 volt ungrounded delta system is 480V. NEC 250.97 applies. The voltage to ground for ungrounded circuits is the greatest voltage between the given conductor and any other conductor of the circuit. For a 3-phase, 3-wire ungrounded 480-volt system the voltage to ground is 480-volts.

What happens if you don’t ground a transformer?

There is no return circuit to earth and therefore nothing can flow through you to earth and back to the transformer to cause a shock. One may therefore safely touch EITHER output lead and not receive a shock as there is no earth reference.

What is the phase to ground voltage on a 480 volt delta system?

The phase to ground voltage on a 480 volt ungrounded delta system is 480V. NEC 250.97 applies. The voltage to ground for ungrounded circuits is the greatest voltage between the given conductor and any other conductor of the circuit. For a 3-phase, 3-wire ungrounded 480-volt system the voltage to ground is 480-volts.

What is the definition of a corner grounded delta system?

Definitions. Corner-Grounded Delta System A system in which the transformer secondary is delta-connected with one corner of the delta solidly grounded. Corner-grounded delta systems are also referred to as grounded B phase systems, grounded phase services, and end-grounded delta systems. Also, what is an ungrounded delta system?

Is it possible to have a 480 Delta 3 phase?

It is possible to have a 1to1 ratio xfmr where the primary would be delta and secondary wye to give a 480/277 system. But if I were you I’d be very hesitant about what you do in this building seeing as at any point you could recieve a 480 volt electrocution.

When do you find 480 to ground on two phases?

Be careful when you find 480 to ground on two phases and one phase at zero to ground. Unless you see the ground connection between the transformer secondaries and ground it may be an ungrounded system with a fault in it. If you see fuses on only two phases it should be a grounded system.