This post When and Why Did the U.S. Transition from 110V to 120V Supply? appeared first on ELECTRICAL TECHNOLOGY. Why Did the Voltage Level Increased from 110V to 120V in North America? Electric power transmission and distribution is not as straightforward in the U.S. as it is in IEC-following countries. For instance, most of these countries including the UK, Australia, and many European and Asian nations (except Japan) use 230V for single-phase and 400/415V … Visit the When and Why Did the...