Why some bench power supply comes with yellow label stating 100V ONLY or 115V ONLY?
The main purpose of the yellow label (as shown below) is to caution customer the AC Power rating shipped from the factory that the unit to be powered by 100V or 115V supply. This is to provide additional visual warning to customer as not to accidentally connect the unit to a higher voltage supply causing the fuse protection to blow. This scenario will not occur for a 230V fitted power supply.
User is responsible to remove and replace any tag or label showing the previous rating with their own latest installed rating if the unit is subjected to any modification.