I thought that the US standard is 117 volts. The odd value of 117 V is the RMS (root mean square) of a sine wave corresponding to 165 V peak, which is 330 V peak to peak. Wikipedia Mains electricity - Wikipedia, the free encyclopedia says that the standard is 120 V and that 110, 115 and 117 volts have been used in the past. So I guess it is 120 V.

- BOB