1/0 medium voltage. There are 3 vaults between switch and transformer. Between vaults A-B a true tape measures 331'. Between B-C measures 98' between A and transformer can't be measured to accurately but is 100' with a wheel. And finally between C and the switch is 8' and the duct bank is 7' below grade. Also the 3 vaults are pour in place about 6' square. Remember the wires have to be racked in each vault.