Pressure Switch MDR

Pressure switches are mainly used to switch pump and compressor motors on and off depending on the pressure so that the pressure of a given media within a tank does not exceed an upper or fall below a lower value. The upper pressure value by which e.g. a pressure switch breaks an electric circuit (NC function) is called the cut-out pressure. The lower pressure value by which the pressure switch makes an electric circuit is called the cut-in pressure. Both cut-out and cut-in pressures within a given range can be set on the pressure switch. The reversed switching function by which the upper setting point makes an electric circuit and the of a lower setting point breaks the electric circuit is called NO function. The pressure switch related difference between cut-in and cut-out pressures is called hysteresis. Every pressure switch allows the natural hysteresis to be increased by a differential adjustment. An easy two-point control with a pressure switch is thus feasible.

Control pressure switches represent a special group within pressure switches. These devices are especially suitable for monitoring and controlling purposes. Depending on the model, SPDT's with or without goldflashed contacts e.g. for PLC applications or isolated NO and NC contacts are available. Depending on the pressure switch type, loads with a max. power consumption of 1.1 kW can be started directly.


High performance pressure switches for

AC currents


favored media: air and water

2 NC

  • MDR 1
  • MDR 11
  • MDR 2
  • MDR 21

High performance pressure switches for

AC currents


Favored media: air and water

3 NC

MDR-4 SU is also available with 3 NO

  • MDR 3
  • MDR 4 S
  • MDR 4 SD
  • MDR 4 SU
  • MDR 5

Control pressure switch

1 change-over contacts

  • MDR F..H with die-cast aluminum flange
  • MDR F..Y with plastic-flange
  • MDR F..HE with stainless-steel-flange
  • MDR F..HH high pressure
  • MDR F..with reset function
Control pressure switch
  • MDR 43 1 NC, 1 NO
  • MDR 53 1 change-over contacts

image: MDR-F 32H-S, MDR 4/6, MDR 5/11