Transformer neutral

[Razzap]

The new addition to our shop is fed from a 3-Phase Y-Delta 480 V pad transformer. The lighting is 277 V. The neutral is taken from the PRIMARY of the transformer, because the Delta is only 480 V, not center or corner grounded. Is this per Code? Is this electrically possible? Of all the transformer wiring diagrams I have ever seen, never is there a neutral from the primary side used on the secondary. It seems to work this way, but it makes no sense to me.

 

[brian john]

No and it won't work, you need to get a transformer for the lighting either 480 to 277 single phase or 480 delta to 480/277 wye.