AERCO Modulex E8 Controller (and BCM) For Modulex EXT Boilers - Manual (Page 90)

E8 Controller and BCM for Modulex EXT
Installation, Operation & Maintenance Manual
CHAPTER 8: BOILER COMMUNICATION MODULE (BCM)
Page 90 of 108 AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 OMM-0093_0A
PRI: 06/24/2013 Phone: 800-526-0288 GF-136-C
start level percentage (programmed by the user into the BMS II/ACS), the BMS II/ACS will call
on the second boiler to begin firing one module, and the BMS II/ACS will then split the fire rate
signal between the two boilers and send each a signal equal to the start level
percentage. When the combined BMS II/ACS fire rate signal to the two boilers reaches a value
three times that of the start level percentage, the BMS II/ACS will call on the third boiler to begin
firing one module, and the BMS II/ACS will then split the fire rate signal between the three
boilers and send each a signal equal to the start level percentage. As the demand increases, in
a similar method as above, the BMS II/ACS will call on the BCM of the fourth boiler to turn on
one module. At this point, the BMS II will modulate the fire rate signal to the boilers in a parallel
manner, while the BCM of each boiler sequences the individual modules.
Boiler inputs will modulate down and come off line in response to the BMS II/ACS in a reverse
manner. Whether the BMS II/ACS is set in a Constant Temperature or Modulating Temperature
mode, it will use the modulating ability to prevent header temperature fluctuation and maximize
efficiency. As well, the BMS II/ACS can stage auxiliary equipment such as combustion air
dampers and fans. Refer to BMS II Operations and Maintenance Manual GF-124/ACS Manual
GF-131, and Product Spec BMS-II for details.