These pressure switches have adjustment scales that determine the opening or closing point of these contacts.
The low pressure switch has two rulers to reference the low side adjustment of the system, one called “CUT IN” which determines the return value, reset, of the compressor after a low pressure stop and the other called “DIFF”. which shows the difference between the shutdown pressure value and the compressor return value.
The high pressure switch has a ruler called “CUT OUT” whose indication shows the maximum pressure value under which the compressor can operate, this value determines the high pressure shutdown.