AERCO C-More Controls Manual June 2010 - Manual (Page 104)

C-More Controller for Benchmark, Innovation & KC
USER MANUAL
Page 104 of 162 AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, New York 10913 04/22/14
GF-112 Phone: 800-526-0288 OMM-0032_0E
BST Multiple Boiler Light Off sequence
Igniting the first boiler:
1. The BST PID determines that there is a demand for heat and begins a light off sequence.
2. BST executes the “Sequence” firmware to select a Lead Boiler to light off.
3. BST examines the Unit Type and Unit Size of the Lead Boiler to light off and sends the
Lead Boiler a Valve Position (Fire Rate) equal to that boiler’s Start Level to initiate a light
off sequence.
4. The boiler being ignited sets its internal Valve Position (Fire Rate) at its’ own particular
Ignition Position (Low Fire Pct) during the light off Sequence.
5. When the boiler is successfully ignited, it executes either the Warmup Delay, if required, or
the Low Fire Delay, if required. The Warmup and Low Fire Delays will be executed with
the boiler at its Ignition Position (Fire Rate).
6. The BST PID will adjust the boiler’s Valve Position (Fire Rate) as required to achieve and
maintain the required Setpoint temperature.
7. If the Valve Position reaches or exceeds the “BST Next Turn On VP” level, the BST will
attempt to light off another boiler to meet the demand.
Igniting the next boiler:
8. The BST executes the “Sequence” firmware to select the next Lead Boiler to light off.
9. The BST examines the Unit Type and Unit Size of the boiler to light off and sends it a
Valve Position (Fire Rate) equal to that boiler’s Start Level to initiate a light off sequence.
10. The boiler being lit off sets its internal Valve Position (Fire Rate) at its own particular
Ignition Position (Low Fire Pct) during the light off Sequence.
11. When the boiler is successfully ignited, it executes either the Warmup Delay, if required, or
the Low Fire Delay, if required. The Warmup and Low Fire Delays will be executed with
the boiler at its Ignition Position (Fire Rate).
12. During the Warmup or Low Fire Delays, the Valve Position of ANY previously ignited
boilers will remain at their present (Fire Rate) level in order to maintain proper loop
temperature during the extended Wait Periods. The boiler temperatures will be locally
monitored and modulated during this Wait period to prevent overheating.
13. During the Warmup or Low Fire Delays, the “Integral” portion of the BST PID Calculation
will be frozen in order to prevent the PID from un-necessarily “Winding UP” and causing
Overtemp problems.
14. Following the successful light off and delays, BST sets the Valve Position (Fire Rate) of all
previously ignited boilers to 30% to evenly distribute the load among all boilers.
15. The BST PID will now modulate all boilers up or down in order to reach and maintain the
Setpoint Temperature.