Draft Controller

The JC-22D Draft Monitor and Controller is a microprocessor-based draft controller, indicating instrument and alarm monitor.  Draft is continuously displayed using a highly visible backlit LCD display.  An intuitive bargaph display and alarm message provide clear boiler draft status.

Automatic Draft Sequence

• Damper is positioned for purge, light-off, post-purge & burner shutdown
• To prevent pressurizing the boiler during startup, the draft damper opens immediately, and the burner fan start is delayed 0-30 seconds (adjustable)
• The damper is closed when the boiler is off-line to minimize energy waste

Automatic Draft Control Increase Boiler Efficiency

• Reducing the air infiltration into the furnace reduces heat lost up the stack.  Uncontrolled boiler draft results in a more negative boiler pressure and therefore more cold air being drawn into the boiler
• Maintaining a stable and optimum draft despite changes in ambient air temperature, wind velocities, firing rates, and flue pass sooting conditions allows the burner control systems to operate with less extra excess air.  At a given F.D. fan inlet damper position, the air flow through the burner will change as boiler draft changes

Model JC-22D Draft Controller comes with (2) pre-programmed, field selectable control modes:

JC-22D “Floating” Draft Control Mode

• Direct Field Replacement for existing JC-20F11AR2 and similar units
• Compatible with existing electric draft actuator, does not require feedback pots
• Uses proportional control to direct the damper open or closed until the draft returns to setpoint

JC-22D “Precise” Draft Control Mode

• Precise PID control
• “GAP” PID Draft Control uses a dual gain strategy (i.e. lower gain near setpoint, higher gain farther away from setpoint) to allow precise draft control without hunting due to draft pulsations
• Firing rate feedforward allows the controller to instantly respond to changes in firing rate demand without waiting for the outlet pressure to deviate from the acceptable range. This is especially important in Induced Flue Gas Recirculation (IFGR) applications
• Adjustable Start Position directs the outlet damper to 100% for purge and then closes the damper to a pre-determined position for light-off. Boilers with very tall stacks, oversized ID fans, or wide turndown Low NOx burners may not be able to light-off with the outlet damper wide open

The Model E-Link Draft Damper Assembly pre-mounts a DM-1E-P1A-S2 actuator and JC-22XMTR Draft Range Transmitter Assembly. Only a single boiler outlet draft connection is required. The Model E-Link Draft Damper Asssembly is part of a full scope control package that assures safe and efficient control with undivided system responsibility

• Complete draft damper assembly saves installation time and cost by factory mounting actuator, draft transmitter and low draft switch
• The Model E-Link Draft Damper Assembly and JC-22D Draft Controller form a complete draft control package

• +1" wc to –1" wc Draft Transmitter Range
• +0.15"wc to +4.0"wc High Pressure Cut-Out Setpoint (field adjustable)
• 5 Second High Pressure Cut-Out Time Delay Relay
• Transmitter is calibrated as +1”wc = 4 mA to provide fail-safe operation (damper opens)
• Combination Draft Range Transmitter, Independent High Pressure Cut-Out with 5 second time delay relay in one box and a single draft connection saves installation cost

The Model JC-22XMTR Draft Transmitter Assembly is a field mountable boiler draft range transmitter and independent high pressure cut-out switch with 5 second time delay relay, which helps avoid nuisance burner shutdowns due to momentary draft fluctuations.  The transmitter provides a 4-20 mAdc signal for draft control and the time delay relay provides an isolated “High Pressure Cut-Out” contact for use in the Flame Safeguard Limit Circuit.

JC-22D Specifications

Panel
Power Supply: Case Size: Enclosure Type: Ambient Temp.: Displays: Bargraph Range: Alarm Setpoints:	120Vac, +/- 15%, 50/60Hz, 15 VA 8"H x 3.5"W x 7.5"D NEMA 4 faceplate +32° to 122° F High Contrast LCD Display, 4" high, 0.5% Resolution Bargraph -1.00 to +1.00" H2O One (1) adjustable contact with adjustable time delay
Inputs
Draft Input: Firing Rate Input: Discrete Input: Actuator Feedback:	4-20 mAdc digital filtered 300 ohm (minimum) or 4-20 mAdc Five, Optically isolated 120 Vac, 10 mA load 300 ohm min feedback pot (required for GAP PID Control Mode)
Outputs
Relay Outputs: Actuator Outputs: Network:	Three SPDT Relays, 10 A Resistive, 8 FLA, ½ Hp, 120 Vac One Triac pair, 2 FLA/24-120 Vac or 4-20 mAdc 1200 - 38400 Baud; RS485 Modbus, ASCII or RTU

Draft Damper Specifications

Damper Frame: Damper Blades: Inside Diameters: Height: Bolt Holes: Finish: Actuator:

10 gauge Carbon Steel Rolled Channel with mounting holes (2) Opposed Blades, 10 gauge Carbon Steel 12", 16", 20", and 24" consult Factory for nonstandard sizes 8" 16 for 24", 12 for 12",16" and 20" High temperature primer DM-1E-P1A-S2 Rotary Actuator, close coupled to Damper Shaft

Draft Range Transmitter Specifications

Enclosure	NEMA 12, field mounted
Transmitter
Range: Output: Accuracy: Power Supply:	+1"wc to -1"wc 4-20 mAdc (2-wire) +/- 0.75% FS 24 Vdc
High Pressure (Low Draft) Cut-Out
Range: Dead band: Contact:	+0.15"wc to +4.0"wc, field adjustable 0.09"wc (average) 20 amps/120 Vac

JC-22D Ordering Information

To order a “Floating” Draft Control System, specify the following:

1. Specify Model JC-22D Draft Controller with Model JC-XMTR Draft Range Transmitter Assembly
2. Specify DM-2 Electric Rotary Actuator or PL-2 Electric Linear Actuator
3. Alternately, Specify Model JC-22D Draft Controller and Model E-Link Draft Damper Assembly

To order a “Precise” Draft Control System, specify the following:

1. Specify Model JC-22D Draft Controller with Model JC-XMTR Draft Range Transmitter Assembly
2. Specify DM-1E-P1A-S2 Electric Rotary Actuator or R-AL-2-3-P1-4-S2-0 Electric Linear Actuator
3. Alternately, Specify Model JC-22D Draft Controller and Model E-Link Draft Damper Assembly
4. Specify Model SPS Shaft Position Sensor when required

Draft Damper Ordering Information

1. Specify E-Link Draft Damper Assembly
2. Specify Damper Size [12", 16", 20" or 24"], consult factory for larger or non-listed sizes
3. Specify Model JC-22D Draft Controller
4. Specify Model SPS Shaft Position Sensor (not required for “Floating” Draft Control System)

JC-22XMTR Ordering Information

1. Specify Model JC-22XMTR