P28DP

Oil Protection
These controls measure the pressure differential between the pressure generated by the oil pump and the refrigerant pressure at the crankcase.

Product Description

A built-in time delay switch allows for pressure-pick up on start and avoids nuisance shutdowns on pressure drops of short duration during the running cycle.
When the compressor is started, the time delay switch is energised. If the net oil pressure does not build up within the required time limit, the time delay switch trips to stop the compressor. If the net oil pressure rises within the required time after the compressor starts, the time delay switch is automatically de-energised and the compressor continues to operate normally. If the net oil pressure should drop below setting (scale pointer) during the running cycle, the time delay switch is energised and, unless the net oil pressure returns to cut-in point within the time delay period, the compressor will be shut down, and have to be manual reset. The compressor can never run longer than the predetermined time on low oil pressure. Controls are available only for manual reset after cut-out.

Features
•Heavy duty pressure elements
•Safety lock-out with trip-free manual reset
•Ambient compensated timing
•Dust-tight Penn switch

Application
These oil protection controls are designed to give protection against low net
lube oil pressure on pressure lubricated refrigeration compressors.

Ordering Codes Range (bar) Style Time Delay (s) Voltage Switch Action Refrigerant Additional Features
P28DA-9341 0.6 to 4.8 5 50 115/230 15(8) A, 230 VAC, Open Low, Alarm and Safe
Light Contacts
non-corr. Incl 2 flare nuts 7/16″-20 UNF
P28DA-9660 13 90
P28DJ-9360 5 90 IP66 enclosure
P28DJ-9861 15 90 NH3 IP66 enclosure, Incl. 2 connectors CNR003N001
P28DP-9300 5 non-corr. Without time delay
P28DP-9340 50
P28DP-9360 90
P28DP-9380 120 230
P28DP-9381 Concealed adjustment, set 0.65 bar
P28DP-9640 50
P28DP-9660 13 90
P28DP-9680 120
P28DP-9840 50
P28DP-9860 15 90 NH3
P28DN-9750 50 115/230 Concealed adjustment, set 1,5 bar
Technical Document