Mechanical adjustment voltage relay

Mechanical

— adjustment of parameters using mechanical switches, usually rotary, with scales printed next to them. In some models, these switches are manually adjusted, in others they must be turned with a screwdriver or other similar device. This method is simple, reliable and inexpensive, but not as convenient as digital adjustment, and has very low accuracy — for example, the re-closing time can be set with an accuracy of 20-30 seconds at best, and more often up to a minute or two.