3-Element Drum Level Controller


The JC-43D2 3-Element Drum Level Controller maintains a boilers drum level at setpoint by modulating a 4-20 mA control output with a user selectable 1-element, 2-element, or 3-element PID loop.

The JC-43D2 can be configured for an alternate offline setpoint mode to account for sink and swell in the boiler drum as the boiler transitions between online and offline. A user-configured warmup and cooldown delay keeps the PID from modulating until the boiler is making steam, and also allows the control valve to continue modulation for a time period after the boiler is shutdown.

The JC-43D2 can be wired to interface with the burner control to shutdown the burner in the case of a low drum level or high steam pressure condition in addition to external level and pressure switches.

  • Overview and Features
  • Application
  • Specifications
  • Documents
Overview and Features
  • 3-Element PID Drum Level Control
  • Low Steam Flow and Low Feedwater Flow Fallback to 1-Element Control
  • 11-Point User-Configured Steam Flow Feedforward Curve for 2-Element Control
  • High And Low Drum Level Alarms
  • High and Low Steam Pressure Alarms
  • Low Drum Level and High Drum Pressure Shutdown
  • Steam Pressure Compensation for Drum Level and Steam Flow Inputs
  • Level Transmitter Failure Monitoring and Alarm
  • Periodic Water Column Blowdown Reminder
  • 60-Point Time/Date-Stamped Blowdown Maintenance History
  • Alternate Offline Setpoint for Sink/Swell Compensation
  • Warmup and Cooldown Delays before Enabling/Disabling PID Control
  • Steam Flow and Feedwater Flow Totalizers

The JC-43D2 is perfect for retrofits and can be programmed for modulating 1-, 2-, or 3-element drum level control, or for more simple ON/OFF control for solenoid valve or feedwater pump applications.



  • Power Supply: 120VAC +/-15%, 50/60 Hz, 26 VA
  • Case Size: 3 1/2 w x 7 9/16 h x 4 7/8 d
  • Enclosure Type: NEMA 12 Faceplate, Flush Mounting
  • Ambient Temperature: 32°-131° F (0°-55° C) Ambient
  • Digital: Color Touchscreen 4" High, 0.5% Resolution Bar Graph


  • Analog Inputs: (4) 4-20 mA: Drum Level, Steam Flow, Feedwater Flow, Drum Pressure
  • Discrete Inputs: (2) 120VAC: Burner Running Input, Blowdown Bypass PB


  • Relay Outputs: Two SPDT Relays, Two SPST Relays 10 A Resistive, 8 FLA, ½ HP, 120 VAC: Common Alarm, Burner Shutdown, ON/OFF Control Output
  • Analog Outputs: (2) 4-20 mA, 650 Ohm Load Max: Control Output; Drum Level, Steam Flow, or Feedwater Flow Retransmit
  • Network Output: 4800-57600 Baud RS485 Modbus RTU, Ethernet TCP/IP

3-Element Drum Level Controller Specification


3-Element Drum Level Controller Manual


3-Element Drum Level Controller Cutsheet