AERCO C-More Controls Manual June 2010 - Manual (Page 119)

C-More Controller for Benchmark, Innovation & KC
USER MANUAL
04/22/14 AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, New York 10913 Page 119 of 162
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When a boiler is manually selected as the Lead or Lag Boiler, it will remain the Lead or
Lag boiler until either another boiler selection is made, or either Run Hours or Unit Size
is selected as the BST Sequencing Mode.
This feature is useful if the user prefers that a selected boiler will always be lit off first.
Lead/Lag Hours (Span = 25 hours – 225 hours, Default = 72 hours)
If the BST Sequencing item is set to Run Hours, the BST will control the boiler light off and
shutdown, in a calculated manner to equalize the Run Hours of all boilers.
When the Run Hours of the Lead unit exceeds the Run Hours of the Lag Unit by the Lead/Lag
Hours item entry, the BST will cycle down the Lead unit and search for a new Lead unit to light
off in its’ place. The Lead/Lag Hours item is designed to spread the total number of run hours
accumulated on all units in the system so that each of the units have approximately the same
number of run hours.
9.5.5 TEMP CTRL MENU
BST Temp Hi Limit (Span = 40°F - 240°F, Default = 210°F)
The BST Temp Hi Limit is the maximum allowable BST Header Temperature before invoking
the BST Master “BST OVERTEMP” message. Invoking the “BST OVERTEMP” message will not
cause any fault conditions, but will further modulate the BST Fire Rate to lower the header
temperature below this limit.
NOTE! In over-temp conditions, each individual boiler on the BST network will respond to its’
own “Setpoint Limiting” settings and Hi Temp Limit settings to either reduce Fire Rates or invoke
Boiler Over-Temp Faults.
BST Setpoint Lo Limit (Span = 40°F - BST Setpt HI Limit, Default = 60°F)
The BST Setpoint Lo Limit is the Minimum allowable BST Setpoint value entered via:
• The C-More Keypad in BST Constant Setpoint Mode.
• The Remote Signal in BST Remote Setpoint Mode.
BST Setpoint Hi Limit (Span = BST Setpt Lo Limit - 220°F Default = 195°F)
The BST Setpoint Hi Limit is the Maximum allowable BST Setpoint value entered via:
• The C-More Keypad in BST Constant Setpoint Mode.
• The Remote Signal in BST Remote Setpoint Mode.
BST Prop Band (Span = 1°F - 120°F, Default = 100°F)
The BST Prop Band item is the Proportional component of the PID control algorithm. The BST
Prop Band generates a valve position based on the error that exists between the BST Setpoint
temperature and the actual header temperature. If the actual error is less than the proportional
band setting (1 to 120°F), the valve position will be less than 100%. If the error is equal to or
greater than the proportional band setting, the valve position will be 100%.
Smaller values (below 70°F) for BST Prop Band will result in more aggressive Fire Rate
changes to reach setpoint temperature. This can cause excessive cycling (or hunting) while
trying to reach setpoint temperature.
BST Integral Gain (Span = 0.00 - 2.00, Default = 0.50)
The BST Integral Gain item is the Integral component of the PID control algorithm.