Johnson Controls P28DN-4 8/70# 30Sec Mr W/Alarm Lubeoil

Description:

The P28 controls provide dependable and economical oil pressure cutout for pressure lubricated refrigeration compressors. The factory set pressure adjustment provides operation to the compressor manufacturer’s specifications. The P28 measures the net oil pressure available to circulate oil through the lubrication system. (Net oil pressure is the difference between the oil gage pressure and the refrigerant pressure in the crankcase.) A built-in time delay relay, accurately compensated for ambient temperature, allows for pressure build-up on start and avoids nuisance shutdowns on short duration pressure losses during the running cycle. When supplied with terminal no. 3, the control may be wired to operate a runlight to indicate when sufficient net oil pressure is present. Terminal A is supplied when a shutdown alarm or signal is desired. The P28 control is for use at normal room temperatures of 32 to 104ºF (0 to 40ºC) and in areas protected from the weather. All Series P28 controls are designed for use only as operating controls. Where an operating control failure would result in personal injury and/or loss of property, it is the responsibility of the installer to add devices (safety, limit controls) or systems (alarm, supervisory systems) that protect against, or warn of, control failure.