AERCO C-More Controls - Manual (Page 34)

C-MORE CONTROL PANEL OPERATION
Wire the units using shielded twisted pair wire
between 18 and 22 AWG. Observe the polarity
shown for the B.M.S. (PWM) IN connections.
The shield is connected at the BMS to any
minus (-) boiler terminal and the boiler end of the
shield must be left floating. Each unit’s wiring
must conform to the above.
5.3.5.2 Boiler Management System Setup
and Startup
This mode of operation is factory preset and the
AERCO BMS Model 168 controls the firing rate.
There are no setup instructions for each
individual unit.
To operate the unit in manual mode, press the
AUTO/MAN switch. The REMOTE LED will go
off and the MANUAL LED will light
To change back to the BMS mode, simply press
the AUTO/MAN switch. The REMOTE LED will
again light and the MANUAL LED will go off.
5.3.6 Combination Control System
(CCS)
NOTE
Only BMS Model 168 can be utilized for
the Combination Mode, not the BMS II
(Model 5R5-384).
A Combination Control System is one that 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, enough
boilers are installed to cover the space-heating
load on the design day, however one or more
units are used for the domestic load.
The theory behind this type of system is that the
maximum space-heating load and the maximum
domestic hot water load do not occur
simultaneously. 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.
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.
5.3.6.1 Combination Control System Field
Wiring
Wiring for this system is between the BMS
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.
5.3.6.2 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 220°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 2.2 for instructions on
changing menu options.
While it is possible to change other temperature-
related functions for combination mode, the unit
is factory preset. These preset settings work
well in most applications. It is suggested that
AERCO be contacted prior to changing settings
other than the unit’s setpoint.
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