AERCO BMK 3.0 LN Dual-Fuel Series Gas Fired Low NOx Boiler System - Manual (Page 47)

MODE OF OPERATION
5-5
When the space-heating load is such that all the
space-heating boilers are at the 100% valve
position, the BMS will then ask the Combination
Control Panel for the domestic boilers to
become space-heating boilers. Provided the
domestic hot water load is satisfied, the combo
(hot water) boilers will then become space-
heating boilers. If the domestic hot water load is
not satisfied, the combo boiler(s) remain on the
domestic hot water load. If the combo boilers
switch over to space heating, but there is a call
for domestic hot water, the CCP switches the
combo units back to the domestic load.
When the combo units are satisfying the
domestic load they are in constant setpoint
mode of operation. When the combo units
switch over to space heating, their mode of
operation changes to the BMS mode. For more
information concerning the operation of the
Combination Control Panel see the AERCO
CCP-1 literature.
5.7.1 Combination Control System Field
Wiring
Wiring for this system is between the BMS
Model 168 panel, the CCP and the B.M.S.
(PWM) IN terminals in the I/O Box. Wire the
units using a shielded twisted pair of 18 to 22
AWG wire. When wiring multiple units, each
unit’s wiring must conform to the above. For a
complete CCP system-wiring diagram see the
AERCO CCP-1 literature.
5.7.2 Combination Control System Setup
and Startup
Setup for the Combination Mode requires entries
to be made in the Configuration Menu for boiler
mode, remote signal type and setpoint. The
setpoint is adjustable from 40°F to 240°F.
Enter the following settings in the Configuration
Menu:
MENU OPTION SETTING
Boiler Mode Combination
Remote Signal BMS (PWM Input)
Internal Setpt 40°F to 240°F
Refer to paragraph 3.3 for instructions on
changing menu options.
While it is possible to change other temperature-
related functions for combination mode, thes
functions are preset to their factory default
values. These default settings work well in most
applications. It is suggested that AERCO be
contacted prior to changing settings other than
the unit’s setpoint. For a complete listing of
temperature related function defaults, see
Appendix E.
To set the unit to the manual mode, press the
AUTO/MAN switch. The MANUAL LED will
light.
To set the unit back to the auto mode, press the
AUTO/MAN switch. The MANUAL LED will go
off and the REMOTE LED will light.
When the boiler is switched to BMS mode, the
AERCO BMS controls the valve position. There
are no setup requirements to the boiler(s) in this
mode.