I mean the electrical utility power that connects to the transformer outside of the home or other buildings. i.e. what is the primary winding voltage of the transformer having 220 VAC center-tap secondary?

i have heard as high as 13 kV, but that seems kinda high. isn't it more like 4 kV?

  • \$\begingroup\$ It varies but around here it's 7.2kV. That would be a 12,470 wye. \$\endgroup\$ – isdi Oct 22 '18 at 17:26
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    \$\begingroup\$ High enough not to go near it, end of... \$\endgroup\$ – Solar Mike Oct 22 '18 at 17:29

12470V (delta)/7200V (Wye)

13200V (delta)/7620V (Wye)

24940V (delta)/14400V (Wye)

34500V (delta)/19920V (Wye)

source is bulletin 1724-D-114 USDA rural distribution system

  • \$\begingroup\$ i know what Y and Δ is and i know about \$\sqrt{3}\$, but in the expression: "12470Y/7200", what is the 7200? because i would expect the Delta voltage to be \$\sqrt{3}\$ times the Wye voltage. \$\endgroup\$ – robert bristow-johnson Oct 22 '18 at 17:58
  • \$\begingroup\$ I would also expect some 'V' symbols in there. \$\endgroup\$ – Transistor Oct 22 '18 at 18:10
  • \$\begingroup\$ i think volts is assumed. unless i see "kV" in there. \$\endgroup\$ – robert bristow-johnson Oct 22 '18 at 18:11
  • \$\begingroup\$ You are correct, I believe they/I have a typo in the "Y/"order. Fixing now. \$\endgroup\$ – isdi Oct 22 '18 at 18:13
  • \$\begingroup\$ Volts is correct, thought about the whole ',' vs '.' nomenclature left unambiguous (though it would be one heck of a wire at 12.47V :-) \$\endgroup\$ – isdi Oct 22 '18 at 18:17

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