233P Series - Single-Phase Pump Monitor

Littelfuse Motor and Pump Protection Relays
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The 233P is a single-phase pump monitor designed to protect single-phase pumps from dry-well, dead-head, jammed impeller, rapid cycle, overvoltage and undervoltage conditions. The 233P protects 230 volt, 2 or 3 wire, 1/3 to 3hp pumps.

A calibration adjustment allows the 233P to be calibrated to your specific pumping applications, thereby reducing the possibility of false or nuisance tripping. A proprietary microcontroller based voltage, power factor and current-sensing circuit constantly monitors for power fluctuations, overcurrent and underload conditions. When an abnormality, such as loss of suction, is detected, the 233P deactivates its output relay and directly disconnects the pump motor. The relay then begins its user-selectable “Restart Delay” (dry-well recovery) timer. When the timer expires or power is removed and reapplied, the relay reactivates its output relay and allows the pump to turn back on.

An infrared LED communicates directly with a hand-held diagnostic tool called the Informer (sold separately).

NOTE: The 233P 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, you increase the sensitivity closer to the 90% mark, or if you have a very heavy producing well, you would decrease the sensitivity around the 70% mark.

Access specifications, certifications, check availability and order parts below

Catalog #Input
Voltage (V)
Input Load Range (hp)Output
Form
Termination TypeMounting MethodDimensionsWeight (lbs/g)Compare
233P230VAC1/3 - 3 hpSPSTTorque: 13 in-lbs; Wire: Stranded or solid 10-22AWG#8 screws2.93î H x 5.25î W x 2.91î D (73.7 x 133.4 x 74.0 mm)0.88 lb. (14.0 oz. 396.9 g)
233P-1.5230VAC1/3 - 1.5 hpSPSTTorque: 13 in-lbs; Wire: Stranded or solid 10-22AWG#8 screws2.93î H x 5.25î W x 2.91î D (73.7 x 133.4 x 74.0 mm)0.88 lb. (14.0 oz. 396.9 g)
233P-1.5-ENCL230VAC1/3 - 1.5 hpSPSTTorque: 13 in-lbs; Wire: Stranded or solid 10-22AWG#8 screws8.30î H x 5.36î W x 3.68î D (210.8 x 136.1 x 93.5 mm)3 lbs. (36 oz. 1 020.6g)
233P-ENCL230VAC1/3 - 3 hpSPSTTorque: 13 in-lbs; Wire: Stranded or solid 10-22AWG#8 screws8.30î H x 5.36î W x 3.68î D (210.8 x 136.1 x 93.5 mm)3 lbs. (36 oz. 1 020.6g)