SJE MicroMaster® Plus WS

Mechanically-Activated, Wide-Angle Pump Switch

micromaster plus ws

The SJE MicroMaster® Plus WS pump switch is specifically designed as a mechanical alternative to the mercury-activated Junior Super Single® pump switch. It directly controls pumps in water and sewage applications.

The SJE MicroMaster® Plus WS pump switch is not sensitive to rotation or turbulence, allowing it to be used in both calm and turbulent applications.

micromaster plus ws


  • Mechanically-activated, snap action contacts
  • High impact, corrosion resistant, polypropylene float housing
  • Adjustable pumping range of 8 – 36 inches (20 – 91 cm)
  • For pump up or pump down applications as specified by part number
  • With a 125 VAC or 250 VAC piggy-back plug
  • Without a plug for direct wiring in 125 VAC or 250 VAC applications
  • In standard cable lengths of 10, 15, 20, or 30 feet (3, 5, 6, or 10 meters)
UL Recognized, CSA Certified
Five-Year Limited Warranty


  • Flexible 16 gauge, 2 conductor (UL, CSA) SJOW, water-resistant (CPE)
  • 2.74 inches diameter x 4.83 inches long (7.0 cm x 12.3 cm) high impact, corrosion resistance, polypropylene housing for use in water up to 140°F (60°C)
  • 33 feet (10 meters) or 13 PSI (90 kPa)
  • 125 VAC 50/60 Hz Single Phase:
    • Maximum Pump Running Current: 13 amps
    • Maximum Pump Starting Current: 78 amps
  • 250 VAC 50/60 Hz Single Phase:
    • Maximum Pump Running Current: 12 amps
    • Maximum Pump Starting Current: 72 amps

NOTE: This switch is not recommended for controlling electrical loads less than 100 milliamps, 12 VAC or non-arcing electrical loads. This switch must be used with pumps that provide integral thermal overload protection.

A Pump Switch is designed for Horsepower (HP) rated loads and is not suitable for control (pilot duty) applications. It will fail prematurely when switching loads less than 1 Amp at 120 VAC. Select a float switch from our Control Switch offering for control applications.


Available Downloads
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