Do Buck-Boost transformers present a safety hazard compared to conventional autotransformers?
Buck-Boost transformers only change voltage by a small amount, such as 208 to 240 volts. This small increase does not represent a safety hazard. Conventional autotransformers, manufactured as single winding transformers, change much higher magnitudes of voltage, e.g. 480 to 240 volts. In a system where the line is grounded, it is possible to have 480 volts to ground when the expectations are that 240 volts is at the output. For this reason, qualified personnel only should maintain conventional autotransformers.