I am using 415 V supply. Line to phase neutral is 240 V. I have 110 V appliances that I want to use. I have created 11 different points for which I want to use this appliances, and want to install a three phase panel for it.

What three phase step-down transformer should I use that will give me phase to neutral voltage of 110 V?


You don't need to use a three-phase transformer if you only need a single-phase 110 V supply. If you're going to put in eleven 110 V points you may want to use three-phase just so that the loads on each phase are reasonably balanced.


simulate this circuit – Schematic created using CircuitLab

Figure 1. Star (wye) connection and delta connection. (Voltages are standard European voltages.

You can use transformers with 240 V or 415 V primaries depending on whether you are connecting in star (wye) or delta. Figure 1 shows only one phase. You need to figure out whether the 110 V secondaries are to be isolating or have one conductor neutralised or centre-tapped for 55-0-55 configuration depending on your application and local regulations.


You should use 415/190, since line to line of 110 V is 190 V.

  • \$\begingroup\$ In its current form this answer seems to suggest powering 110V appliances with 190V. \$\endgroup\$ – Dmitry Grigoryev Apr 25 '19 at 7:53

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.