Draft Controller

JC-22D

The JC-22D Draft Monitor and Controller is a microprocessor based draft controller, indicating instrument, and alarm monitor.  The JC-22D includes advanced control algorithms for tall stacks, multiple furnace stacks, and fast varying loads. Read more about our history and expertise in draft control on our blog "Draft Controls: Then and Now.

  • Automatic Draft Control
  • Precise Outlet Draft Control
  • Floating Draft Control
  • Damper Automatically Positioned
  • Adjustable Outlet Damper Start Position
  • Low Draft Alarm Message and Contact
  • Flexible Communications for Data Logging
  • Overview and Features
  • Application
  • Specifications
  • Documents
Overview and Features

The JC-22D Draft Monitor and Controller is a microprocessor based draft controller, indicating instrument, and alarm monitor. The JC-22D directly accepts a 4-20 mADC draft transmitter signal, 120 VAC flame safeguard interface, and outputs a solid state switching (Triac) or 4-20 mADC outlet damper actuator control signal. Draft is continuously displayed using a highly visible backlit LCD display.  An intuitive bar graph display and alarm message provides clear boiler draft status. All adjustments can be made directly from the faceplate of the instrument by scrolling through user friendly, English language menus. The outlet damper may be controlled in “Auto” or “Manual” mode and will automatically sequence through the purge, light-off, post-purge & burner shutdown modes in response to flame safeguard system inputs. The JC-22D automatically positions the outlet damper according to burner operation based on either the field selectable “Floating” or “Precise Draft” Control modes.

  • Automatic Draft Control
  • Precise Outlet Draft Control
  • Floating Draft Control
  • Damper Automatically Positioned
  • Adjustable Outlet Damper Start Position
  • Low Draft Alarm Message and Contact
  • Flexible Communications for Data Logging
Application

Uncontrolled stack draft can cause burner instability, unreliable ignition, and affect fuel-air ratio control repeatability. Burner manufacturers typically recommend draft controls be installed in applications where:

• Stack height exceeds 75 feet
• Multiple furnaces are connected to a single stack

Specifications

Panel


Power Supply:           120 VAC, +/- 15%, 50/60 Hz, 15 VA
Case Size:                   8" H x 3.5" W x 7.5" D
Enclosure Type:         NEMA 4 faceplate
Ambient Temp.:         +32° to 122° F
Displays:                     High Contrast LCD Display
                                     4" high, 0.5% Resolution Bargraph
Bargraph Range:       -1.00 to +1.00" W.C.
Alarm Setpoints:        One (1) adjustable contact with adjustable time delay

Inputs


Draft Input:                4-20 mADC digital filtered
Firing Rate Input:      300 ohm (minimum) or 4-20 mADC
Discrete Input:           Five, Optically isolated 120 VDC, 10 mA load
Actuator Feedback:   300 ohm min feedback pot (required for GAP PID Control Mode)

Outputs


Relay Outputs:         Three SPDT Relays 10 A Resistive, 8 FLA, ½ HP, 120 VAC
Actuator Outputs:   One Triac pair, 2 FLA/24-120 VAC or 4-20 mADC
Network:                  1200 - 38400 Baud; RS485 Modbus, ASCII or RTU

Documents

Draft Controller Specification

Draft Controller Instruction Manual

Draft Controller Cutsheet

Draft Controller Brochure

Draft Controller Wiring Diagram