AERCO C-More Controls Manual June 2010 - Manual (Page 45)

C-More Controller for Benchmark, Innovation & KC
USER MANUAL
04/22/14 AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, New York 10913 Page 45 of 162
OMM-0032_0E Phone: 800-526-0288 GF-112
3.1.1 Deadband High & Deadband Low
The Setpoint, Deadband High and Deadband Low define a PID Correction Deadband in which
the outlet temperature is allowed to drift. Allowing the outlet temperature to drift within this range
(Figure 3-1) minimizes Air/Fuel Valve corrections when deemed unnecessary.
When the Setpoint Temperature is reached, and remains stable for a period of 15 seconds, the
deadband mode is enabled and the °F or °C LED will flash on and off.
No Air Fuel Valve corrections will be attempted until the Outlet Temperature exits the Deadband
zone.
Setpoint
Setpoint + Deadband High
Setpoint - Deadband Low
Deadband
Zone
Outlet
Temp
Figure 3-1: PID Correction Deadband
The PID correction Deadband feature is active for both Boilers and Water Heaters. However,
this feature is not active in the Direct Drive Mode
3.1.2 HI DB Setpt EN Function
When firing at close to the shutdown limit (minimum Valve Position), the C-More will strive to
delay the unit shutdown to Standby Mode for as long as possible while still maintaining
adequate temperature control.
When the Valve Position is less than the Hi_DB_Setpt_En setting, (Figure 3-2), the Outlet
Temperature target is not Setpoint but Setpoint + Deadband_High.
This means that when operating close to the Shutdown Limit we will strive to increase the Valve
Position by changing the Setpoint Temperature to the Setpoint + Deadband_High Temperature
limit thus delaying the Shutdown.