Model 352

SKU: 352

Pump Controller, Two Relay, 4-20mA

The Delta Controls Model 352 was designed to be operated as an alarm unit and/or adjustable differential level controller. It has 2 relays. Each relay has an individual 0-100% “On” and 0-100% “Off” setpoint. It accepts a 4-20 mADC input signal which is proportional to some process variable (usually level). The 352 is microprocessor based and checks its input signal loop for integrity. The relays may be set up for “Direct” or “Reverse” “Fail-safe” action.

The 352 is equipped with a built-in loop power supply, and it can accept a remotely powered 4-20 mADC signal. The input signal wiring may be equipped with an electrical barrier for intrinsic safety. The transmitter must be intrinsically safe for the loop and the 352 input to be intrinsically safe. The 352 must be located in a “safe” area. The input signal wires may extend into the ignition hazard area.

The 352 may be operated in the pump controller mode. Features, such as lead-lag pump rotation, time delay starting, and alarms may be programmed in the field. Up to 2 pumps can be controlled and/or 2 alarm points can be actuated from a single module.


  • Microprocessor based
  • Available for mounting in Delta Controls housings or in in enclosures by others. Housings may be surface or pipe stand mounted
  • Optional direct reading LCD display
  • Accepts 4-20 mADC signal from any type transmitter; 2, 3 or 4 wire
  • Supplies DC power for 2-wire loops and for 3 or 4-wire transmitters
  • Field selectable fail safe action
  • Optional pump control functions
  • Lead/lag control
  • Relay operate time delays
  • Two alarm points
  • Built-in loop power supply
  • Selectable starting time delay
  • Self checking diagnostic routine
  • Will not lose memory
  • Continuous setpoint indication
  • Optional explosion proof housing


  • General Type: Microprocessor based
  • Supply Power: 120 or 240 VAC, 50/60Hz; or 24 VDC; ±15% variation
  • Input Range: 4-20 mADC
  • Relays: Two 10 amp @ 250VAC SPDT
  • Switching Action: Alarm action is basic; adjustable differential for on/off control may be selected
  • Accuracy: 0.1% of full scale
  • Transmitter Loop Power Supply: 24 VDC
  • Multiple Pump Control: Selectable lead/lag; rotation of up to two pumps
  • Readout Display: Optional, 3-1/2 digit LCD; may be field calibrated to be direct reading in engineering units.
  • Temperature Range: -20 to +170°F
  • Signal Loop With Optional Barrier: Intrinsically safe, Classes 1&2, Divisions 1&2, Groups ABCD,EFG. Refer to Application Note #550-998 for details.

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