Mike Dolt Enterprises
Mike Dolt Enterprises
User: kinnirish, Location: Wisconsin
Asked on: Friday, April 15, 2011 at 10:38 pm EDT
Answered on: Tuesday, May 14, 2024 at 4:15 am EDT
Question: I have an Italian packaging machine i am installing in a facility with 480 volt delta incoming power. The machine is has a 415 volt, three phase, 50 hz configuration for all the hardware. I am pulling the original 400 v/50 hz control transformer due to the need for 230 volt single phase demand for inverters, power supplies, and heaters. If the existing control transformer is supplied with 480 volts, my output will be 277v which is too high. question is: can I "corner ground" a 480v to 240 v single phase delta transformer to achieve the 240v to neutral voltage needed, or should i purchase a delta/wye transformer to achieve this. I don't wish to purchase another transformer if I can make this work. Any ideas? your help would be greatly appreciated.
Can you "corner ground" a 480V to 240V single-phase delta transformer to achieve the 240V to neutral voltage needed?Yes, you can. Corner grounding a delta transformer is a technique used to create a neutral point and derive a 240V single-phase voltage from a three-phase delta supply.
Here's how to do it
1.
Connect the delta transformer's terminals A, B, and C to the 480V delta power supply.2. Connect one end of your load (inverters, power supplies, heaters) to terminal A.3. Connect the other end of your load to a neutral point created by grounding one of the delta transformer's windings.
In a delta transformer, the windings are connected in a closed loop, so grounding one winding creates a neutral point. The voltage between the neutral point and any of the other terminals is approximately 240V.
Note
Corner grounding a delta transformer reduces the available power capacity by about 33%. The neutral point is not true ground, so it should not be used for grounding purposes.
Would it be better to purchase a delta/wye transformer?
Purchasing a delta/wye transformer is a more desirable option because: It provides a true neutral point with zero current. It maintains the full power capacity of the transformer.* It provides better isolation and improved voltage regulation.
Conclusion:
While corner grounding a delta transformer is a possible solution, it is not as efficient or reliable as using a delta/wye transformer. If you have the resources, it is recommended to purchase a delta/wye transformer for optimal performance. Flag for review