234-P Series - Littelfuse 234-P PumpSaver® Provides Exceptional System Protection

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The PumpSaver® Plus Model 234-P protects single-phase pumps from dry-well, dead-head, rapid-cycle, jammed impellers, and over/undervoltage conditions. Typical applications include residential waterwells, commercial waterwells, irrigation wells, golf courses, and other sprinkler systems. The Model 234-P is designed to be mounted inside a Grundfos™ control box* to protect ⅓–3 hp, 2- or 3-wire, 230 V pumps. An infrared LED communicates directly with a hand-held diagnostic tool called the Informer (sold separately).

A calibration adjustment allows the 234-P to be calibrated to your specific pumping applications, 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 234-P deactivates its output relay and directly disconnects the pump motor. The 234-P then begins its user-selectable restart delay (dry-well recovery) timer. When the timer counts to zero or power is removed and reapplied, the 234-P reactivates its output relay and turns the pump back on. By leaving the restart delay knob in the reset position, the 234-P will operate in manual reset mode.

The Informer displays parameters including calibration points, trip points, run time and last faults. An IR Kit-12 (12” fiber optic kit) allows the Informer to access these parameters even when the 234-P is enclosed in a control box. This is valuable for troubleshooting the pump while it is running.

NOTE: The PumpSaver® models have a sensitivity adjustment for the dry-well trip point. After calibration is done, you can adjust the sensitivity for the dry-well/dead-head trip point from 70% - 90% of the full load. This makes the unit even more adaptable to varying pumping applications. If you have a very low producing well, increase the sensitivity closer to the 90% mark, or if you have a very heavy producing well, decrease the sensitivity around the 70% mark.
*The Model 234-P is not recommended for use with the Grundfos Deluxe Control Box.


  • Proprietary microcontroller-based circuitry
  • Onboard sensitivity adjustment
  • 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 ConsumptionRapid Cycle Timer (s)Restart Delay RangeTrip Delay RangeUnderload (%)Undervoltage Reset Voltage (%)StockSamples
234-P230 Vac1/3 - 3SPSTInside a Grundfos® control box0 Kg125% of calibration point50 / 60 (50 will increase all delay timers by 20%)3 hp @ 240 Vac (17 A max.)265 Vac≤5 W4 restarts allowed in 60 s periodOver/Under Voltage: 2 s; All other faults: Manual; 2 - 225 mOvercurrent: 5 s; Dry-well: 4 sAdjustable (70 to 90% of calibrated run power)190 VacCheckOrder
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