AERCO KC1000 Low NOx Boiler equipped with C-More version 3.04 - Manual (Page 47)

MODE OF OPERATION
5-5
Combination Control System (CCS) is one that
The theory behind this type of system is that the
When the combo units are satisfying the
stem is between the BMS
5.7 COMBINATION CONTROL SYSTEM
(CCS)
NOTE
l 168 ca Only BMS Mode n be utilized for
the Combination Mode, not the BMS II
(Model 5R5-384).
A
uses multiple boilers to cover both space-heating
and domestic hot water needs. An AERCO
Boiler Management System (BMS) Model 168
and a Combination Control Panel (CCP) are
necessary to configure this system. Typically, an
adequate number of boilers are installed to cover
the space-heating load on the design day,
however one or more units are used for the
domestic hot water load.
maximum space-heating load and the maximum
domestic hot water load do not occur simultane-
ously. Therefore, boilers used for the domestic
hot water are capable of switching between
constant setpoint and BMS modes of operation.
These boilers are the combination units and are
referred to as the combo boilers. The combo
boilers heat water to a constant setpoint
temperature. That water is then circulated
through a heat exchanger in a domestic hot
water storage tank.
When the space-heating load is such that all the
space-heating boilers are at 100% firing rate, 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.
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 sy
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-
To set the unit back to the auto mode, press the
When the boiler is switched to BMS mode, the
related functions for combination mode, these
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.
AUTO/MAN switch. The MANUAL LED will go
off and the REMOTE LED will light.
AERCO BMS controls the firing rate. There are
no setup requirements to the boiler(s) in this
mode.