232 Insider Series - Littelfuse 232-Insider Pump Monitor Provides Exceptional System Protection

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The single-phase 232-Insider PumpSaver® fits inside ⅓, ½, ¾, and 1 hp, 230 V Grundfos control boxes. The PumpSaver 232-Insider is designed to protect single-phase pumps from dry-well, dead-head, jammed impellers, overvoltage, and undervoltage conditions. Typical applications include residential water wells, commercial water wells, irrigation wells, and golf course systems.

A calibration adjustment allows the 232-Insider to be calibrated to your specific pumping application, reducing the possibility of false or nuisance tripping. A unique microcontroller-based voltage and current-sensing circuit constantly monitors the incoming power for fluctuations, overcurrent, and undercurrent. When an abnormality, such as loss of suction is detected, the 232-Insider deactivates its output relay and directly disconnects the pump motor. The 232-Insider then begins its user-selectable restart delay (dry-well recovery) timer. When the timer counts to zero or power is removed and reapplied, the 232-Insider reactivates its output relay and turns the pump back on. By leaving the restart delay knob in the reset position, the 232-Insider will operate in manual reset mode. An infrared LED communicates directly with a hand-held diagnostic tool called the Informer*.

Note: The use of flow restrictors or unusually high head pressures at the time of calibration may interfere with the detection of dead-head conditions.

*The Informer: a hand-held diagnostic tool that uses an infrared receiver to access information that can be helpful for troubleshooting the system (sold separately).


  • Proprietary microcontroller-based circuitry
  • Adjustable restart delay
  • Built-in IR communications link
  • LED indication

Access specifications, certifications, check availability and order parts below

Catalog #Input
Voltage (V)
Input Load Range (hp)Output
Mounting MethodWeight (lbs/g)Overcurrent Trip ClassInput AC Line Frequency (Hz)Output Load Rating (VA)Overvoltage Trip Voltage (%)Power ConsumptionRestart Delay RangeTrip Delay RangeUnderload (%)Undervoltage Reset Voltage (%)StockSamples
232-INSIDER230 Vac1/3 - 1SPSTInside a Grundfos® control box0 Kg125% of calibration point50 / 60 (50 will increase all delay timers by 20%)1 hp @ 240 Vac (17 A max.)265 Vac≤5 WOver/Under Voltage: 2 s; All other faults: Manual; 2 - 225 mOvercurrent: 5 s; Dry-well: 2 sApprox. 80% of calibration point190 VacCheckOrder
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