Chapter 9. Boiler Sequencing Technology; Introduction - Watts Aerco BENCHMARK 750 User Manual

Benchmark 750 – 1000 Boiler User Manual - INTERNATIONAL

CHAPTER 9. BOILER SEQUENCING TECHNOLOGY

CHAPTER 9. BOILER SEQUENCING TECHNOLOGY

9.1 INTRODUCTION

The C-More on-board Boiler Sequencing Technology system (BST) is an integrated 8 Heating
Boiler control system designed into the C-More controller. The BST has its own sophisticated
PID control system designed to simultaneously control the light off and modulation of up to 8
Heating Boilers while achieving maximum operational efficiency.
BST is designed to ensure that all Heating Boilers in the system operate at maximum efficiency.
This is accomplished by lighting off Heating Boilers only if all ignited Heating Boilers reach or
exceed a defined Valve Position (Fire Rate). Operating all Heating Boilers below the defined
Fire Rate "Next on VP" (for Next Turn on Valve Position) insures that they are firing at their most
efficient Fire Rate. One C-More unit is defined as the MASTER unit and all other C-More units
on the BST Modbus Network are defined as SLAVE units. The Master unit will monitor the
system Header Temperature, monitor all Slave units' status information and efficiently control all
units in order to achieve and maintain the required BST Setpoint Temperature.
When there is a demand, the Master unit will light off one of the Heating Boilers based on the
BST Sequencing selection in the BST menu. As system load increases and the valve position of
the ignited units reach the Next On VP (% valve position), the BST master will light off the next
available unit. A simplified block diagram of multiple Heating Boilers connected to a BST is
shown in Figure 9-1 below.
OMM-0119_0A
GF-130-I
Figure 9-1. Simplified BST Block Diagram
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913
Ph.: 800-526-0288
NOTE: Use either
FFWD Header Sensor or
Modbus Header Sensor
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11/03/2016