The A20DP-30 Differential Pressure Swichgage? is a 2" dual-scale dial, diaphragm-actuated differential pressure-indicating gage, with a built in electrical switch.
This switch is used for tripping alarms and/or shutting down equipment. The A20DP-30, with a pressure range of 0-30 psi, is intended to monitor and indicate oil, fuel or water filter restriction and can reduce the risk of dangerously high pressure which may rupture the filter, resulting in contaminants entering the system.
These gauges have an adjustable contact point which triggers upon high pressure.
The gauge is grounded through a seperate earth wire