Thank you "busbar" for your early reply.
I would assume that the switchboard nominal voltage is 220/127V instead of 270/127V. Then all other busbar voltages applied make sense.
The transformer ratio 480/270V might have misled the drawer? I just wonder why such ratio has originally...
Can anybody explain backround for voltages used in a Mexican power plant:
Auxiliary transformer 480/270V Dyn (secondary winding star point solidly grounded)
Switchboard has voltage ratings: 270/127V
I could understand voltages 240/120V as used in US influenced countries but 270/127V? It...
