# 3Phase + Neutral, 208VAC distribution and conversion to 1Phase 120VAC

Question 1: How to convert 3phase+Neutral 208VAC supply to 1phase 120VAC? Can I tap off one (any) leg of the 3phase supply and use that to Neutral to get the 120VAC? Or do I have to use all three phases and load each phase similarly to balance the load of the 120VAC equipment across the three phases?

Question 2: We want to step the voltage up from 3phase 208VAC to 3phase 800VAC and the Step up transformer is wired delta, so we just send the 3 phases to the final load right? Or do we have to continue the neutral line to the final load somehow too?

• Does application always provide balanced load? using Y-delta step up is not advised due to imbalance on power interruptions with voltage imbalance. – Tony Stewart Sunnyskyguy EE75 Mar 4 '18 at 16:49
• @TonyStewart.EEsince'75 No, the load will most likely not be balanced. Can you elaborate on the Y-Delta step up and why it is not advised? I think the people who are working on this currently have issues with unbalanced loads. I am just interested in this topic and would to know more about this if possible please. – Douglas Mar 4 '18 at 19:39

1. $V_{L-N} = \frac {V_{L-L}}{\sqrt 3} = \frac {208}{1.73} = 120 \ \mathrm V$ so, yes, that will work. Generally the supply should be able to take an imbalance but there are too many unknowns in your question to answer definitely.