PS pressure switches are for different technological water system control. They are used most in firefight water systems. With the SPDT relay contact, can operate two pump at once:
If the electric pump stop by any malfunction, the pressure in the firefight water system will cease. The pressure switch sense the drop, and the SPDT microswitch will switch on a pump drived by petrol engine.

The fire sprinkler system supplied by the electric pump.

The electric pump failed, the pressure dropped. PS pressure switch sense the pressure drop, and switched to the petrol engine pump.
Data sheet | PS/3 | PS/3D | PS/5 | PS/5D | PS/12 | PS/12D |
Max. factory pressure | 5 bar | 5 bar | 12 bar | 12 bar | 12 bar | 12 bar |
Pre-set pressure | 0.9 – 2 bar | 0.9 – 5 bar | 1.7 – 5 bar | 1.7 – 7.5 bar | 2.5 – 10 bar | 2.5 – 12 bar |
Min. pressure differential | 0.2 bar | 0.4 bar | 0.5 bar | 0.5 bar | 0.8 bar | 0.8 bar |
Max. pressure differential | 0.2 bar | 2.5 bar | 0.7 bar | 3.3 bar | 1.4 bar | 3.8 bar |
Max. voltage |
5 A – 250 V |