233P - 233P Series

Series: 233P
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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.

Property (Mouseover for details) Value
Input Voltage (V) 230VAC
Maximum Input Power 5W
Input AC Line Frequency (Hz) 50/60Hz (50Hz will increase all delay timers by 20%.)
Input Load Range (hp) 1/3 - 3 hp
Output Form SPST
Output Load Rating (VA) 3 hp @ 240VAC (17 amps max.)
Rapid Cycle Timer (s) 4 restarts allowed in 60s period
Restart Delay Range Over/Under Voltage: 2s; All other faults: Manual 2 - 225m
Trip Delay Range Overcurrent: 5s; Dry-well: 4s
Overvoltage Trip Voltage (%) 265VAC
Undervoltage Reset Voltage (%) 190VAC
Overcurrent Trip Class 125% of calibration point
Underload (%) Adjustable (70 to 90% of calibrated run power)
Termination Type Torque: 13 in-lbs; Wire: Stranded or solid 10-22AWG
Mounting Method #8 screws
Operating Temperature -40° to 55°C (-40° to 131°F)
Dimensions 2.93î H x 5.25î W x 2.91î D (73.7 x 133.4 x 74.0 mm)
Weight (lbs/g) 0.88 lb. (14.0 oz. 396.9 g)