CleaverBrooks CFC-500 Operation, Service And Parts Manual page 152

CB FALCON
Steam Loop Demand and Rate
The CH (Central Heating) Steam Demand and Rate source
compares a selected input sensor to a setpoint.
Burner demand will exist if the sensor pressure falls below the
setpoint minus a hysteresis value. Once the burner demand
signal is on, it remains on until the sensor pressure is above
the setpoint plus a hysteresis value, or until the other selected
demand source input (e.g., Stat, Remote Stat) if any, turns off.
750-265
CH ODR Parameters
Setpoint
TOD Setpoint
Minimum Outdoor Temp
Maximum Outdoor Temp
Minimum Water Temp
Boost Time
Boost Max Setpoint
Boost step
Boost recovery step time
Fig. 10. Outdoor reset parameters.
LL ODR Parameters
Setpoint
TOD Setpoint
Minimum Outdoor Temp
Maximum Outdoor Temp
Minimum Water Temp
Boost Time
Boost Max Setpoint
Boost step
Boost recovery step time
Pump (or output) demand may be driven by the selected
demand source input (Stat input, a remote stat, or by the
sensor alone).
A Proportional-Integral-Differential (PID) controller operates to
generate the demand source's requested modulation rate.
The Steam Central Heating function is implemented as shown
in Fig. 11.
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