Relays Extend Life, Detect Leakage and Control Fluid Levels

Pumps are used in water and wastewater systems, in agricultural irrigation, for water wells, on construction sites, and in a range of energy, medical and industrial applications. Control relays protect pumps from damage, extend pump life, detect shaft seal leakage and control fluid levels.

Macromatic Relays Used For Pump Control:

  • Current Sensing Relays monitor and detect over or under current conditions.
  • Three- Phase Monitor Relays protect equipment from damage due to voltage faults.
  • Alternating Relays equalize the run time of multiple loads.
  • Seal Leak & Temperature Relays protect submersible pump motors.
  • Liquid Level Control Relays detect and control levels of conductive fluids.

Common Challenge

Many duplex pump applications require Sequence On – Simultaneous OFF (S.O.S.O.) operation. The two loads are energized sequentially when the LEAD & LAG switches close, but remain on together until the OFF switch is opened. S.O.S.O. operation results in:

  • Reduced control panel costs by saving space.
  • Fewer components with reduced costs.
  • Reduced assembly time and labor.

Our Solution

In S.O.S.O. control circuits, Macromatic ARP Series Duplex Controllers combine the functions of alternating relay, control relay and auxiliary contacts in one plug-in unit. These relays protect against failures of both OFF and LEAD switches. Compact plug-in design uses standard 8-pin octal socket to save space compared to separate components. A low-profile selector switch for normal alternation or to lock either load to be on first. Two LEDs indicate load to be energized first. To learn more, read our Water and Wastewater Control Solutions fact sheet brochure.

Relay Solutions

Relays Extend Pump Life, Detect Leakage and Control Fluid Levels

Alternating relays


Alternating Relays are used in special applications where the optimization of load usage is required by equalizing the run time of multiple loads. These relays also engage multiple loads if higher simultaneous output is required.


Macromatic Seal Leakage Relays monitor shaft seals on submersible pumps. Over Temperature & Seal Leakage Relays protect pump motors against damage from both conditions. Select from models with plug-in mounting or flange enclosures for mounting on inner panel doors.


LCP Series Liquid Level Control Relays detect & control levels of conductive liquids (tap water, seawater, sewage, chemical solutions, coffee, ice cream, etc.) in pump up or pump down applications.


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