Natural and wastewater treatment
Since 1989
professional solutions
for natural and waste
water treatment

EL-22 electrode relay

  • prevent operation of sucker rod pumps without lubrication
  • control loading/unloading
  • control motor and magnetic valves
  • high and low level alarm signaling
  • dosage
  • adjustable sensitivity


The electrode relay EL-22 is used to control the pump following changes in the liquid level. Single-phase motors of less than 0.37 kW may be driven directly by the EL-22. The electrode relay may only be used with electrically conductive liquids. Its sensitivity is adjustable between 0 and 100 kΩ to match the electrical conductivity of the liquid.


In case the tank is to be unloaded the liquid level first rises up to the level of A-electrodes, after which the relay starts the pump. The relay shuts down the pump when the liquid falls to the level of B-electrodes. The difference between the pump start and stop levels is set by the distance between the electrodes A and B.

In case the tank is to be loaded the pump starts working at the B-level and stops at A-level.

Technical data

  • Mains voltage: 230 V AC
  • Electrode voltage: 18 V AC
  • Electrode current: 0.7 mA
  • Power consumption: 2 VA
  • Rated current: 10 A (active load)
  • Sensitivity range: 0-100 kΩ
  • Case Material: Polycarbonate
  • Dust-proof protection: IP 44
  • Weight: 300 g
  • Case dimensions: 132 X 77 X 93 mm
  • Electrode length: 220 mm
  • Electrode diameter: 12 mm
  • Electrode insulation: Polypropen (PP)