ProFire PF2200-SB Product Manual page 36

V 4.0
2.2.9.3 PID CONTROL
PID Control is the most advanced process control mode, allowing the system to be able to vary the heat
demand in response to the appliance. In this mode, the system utilizes the TCV output to control a
temperature control valve, allowing the system to incrementally change output heat.
The main gas valve outputs (SSV) remain on during PID control unless the process temperature exceeds
the Main Off Setpoint. In this case, the system transitions to the Pilot state and stops PID control. Once
the system cools off such that the process temperature falls below the process setpoint minus the
dead-band, the system will proceed to light off the main and resume PID control.
While in PID control, the system will attempt to maintain the process temperature at the process
temperature setpoint by modulating the system firing rate via the TCV output. As long as there are no
alarms / waits AND the temperature does not exceed the Main Off (or Pilot Off) setpoints, the PID will
continue to function.
Note: this process control mode does not utilize the HFV output.
Section 2: PF2200-SB PRODUCT DESCRIPTION
Page 36 of 85