Obsolete Danfoss PS & PSU Pressure Switch


Danfoss PS & PSU Pressure Switch



Type PS and PSU are pressure-controlled three-pole switches. The position of the contacts
depends on the pressure in the inlet connection and the range setting.
Pressure switch type PS is for the automatic stop and start of motors in compressed air
and water pressure plant (pressure storage tanks.)
Type PSU is especially for compressed air plant where pressure over the compressor
piston must be relieved before starting.

* Connection 1/2 BSP
* Enclosure IP55

OrderCode Type. Set.Range (Bar) Min.Diff (Bar) Max.Diff (Bar) Max Test  Press(Bar) Relief Valve
031E0171 PS4B 1 > 4 0.6 >0.7 3 8 No
031E0172  PSU4B 1 > 4  0.6 >0.7 8 Yes
PS 7B 1 > 7 0.75>1.3 12 No
031E0175 PS9B  2.5 > 9.5  1.2 >1.8  20  No
031E0176 PSU9B 2.5 > 9.5 1.2 >1.8 7 20 Yes
031E0179 PS15B 7 > 15 1.7 >2.3 7 20 No
031E0180 PSU15B 7 > 15 1.7 >2.3 7 20 Yes
031E0191 PSU20  7 > 20 2 >3 11 25 Yes
*** The latest equivalent by Danfoss of the PS and PSU is the CS pressure switch, please note the ranges are not the same so below we have offered an alternative nearest to the old settings, please click on the link to see the new ranges. Also please note for the PSU equivalents do not come with Relief valves, these have to be ordered separately.***


Possible Alternatives
OrderCode Type  Nearest Alternative Order Code New Type Relief Valve needed Order Code
031E0171 PS4B 031E0215 CS  
031E0172 PSU4B 031E0215  CS 031E0298 
031E0182 PS7B 031E0215 or 031E0235  CS  
031E0175 PS9B 031E0235  CS  
031E0176 PSU9B 031E0235  CS 031E0298 
031E0179 PS15B 031E0255  CS  
031E0180 PSU15B 031E0255  CS 031E0298
031E0191 PSU20 031E0255  CS 031E0298
031A0328 PSU12B 031E0255 CS 031E0298