AERCO C-More Controls - Manual (Page 31)

C-MORE CONTROL PANEL OPERATION
The current/ voltage signal can be at either of
the following levels:
4 - 20 mA/1 - 5 Vdc
0 - 20 mA/0 - 5 Vdc
The factory default setting for the Remote
Setpoint mode is 4 - 20 mA/1 - 5 Vdc. With this
setting, a 4 to 20 mA/1 to 5 Vdc signal, sent by
an EMS or BAS, is used to change the unit's
setpoint. The 4 mA/1V signal is equal to a 40°F
setpoint while a 20 mA /5V signal is equal to a
240°F setpoint. When a 0 to 20 mA/0 to 5 Vdc
signal is used, 0 mA is equal to a 40°F setpoint.
In addition to the current and voltage signals
described above, the Remote Setpoint mode
can also be driven by a RS485 Modbus Network
signal from an EMS or BAS.
The Remote Setpoint modes of operation can be
used to drive single as well as multiple units.
NOTE
If a voltage, rather than current signal is
used to control the remote setpoint, a DIP
switch adjustment must be made on the
PMC Board located in the Control Panel
Assembly. Refer to Appendix F for details.
In order to enable the Remote Setpoint Mode,
the following menu setting must be made in the
Configuration Menu:
MENU OPTION SETTING
Boiler Mode Remote Setpoint
Remote Signal 4-20mA/1-5V,
0-20mA/0-5V, or
Network
Refer to paragraph 2.2 for detailed instructions
on changing menu options.
If the Network setting is selected for RS485
Modbus operation, a valid Comm Address must
be entered in the Setup Menu. Refer to Modbus
Communication Manual GF-114 for additional
information.
While it is possible to change the settings of
temperature related functions, the unit is factory
preset with settings that work well in most
applications. It is suggested that an AERCO
representative be contacted, prior to changing
any temperature related function settings. For
descriptions of temperature-related functions
and their factory defaults, refer to Tables 3-1
and 3-2.
5.3.2.1 Remote Setpoint Field Wiring
The only wiring necessary for the Remote
Setpoint modes is the external control wiring
from the source, to the ANALOG IN terminals on
the terminal strip inside the I/O Box. The I/O Box
is located on the left side of the KC Series units
and on the front of Benchmark Series units.
Refer to the wiring diagram (Figure 5-1)
provided on the cover of the I/O Box. For a
Network setting, the connections are made at
the RS-485 COMM terminals in the I/O Box. The
signal must be floating (ungrounded), and the
wire used must be a two wire shielded cable of
18 to 22 AWG. Polarity must be observed and
the source end of the shield must be connected
at the source. When driving multiple units, each
unit’s wiring must conform to the above.
5.3.2.2 Remote Setpoint Startup
Since this mode of operation is factory preset
and the setpoint is being externally controlled,
no startup instructions are necessary. In this
mode, the REMOTE LED will light when the
external signal is present.
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 Remote Setpoint mode,
simply press the AUTO/MAN switch. The
REMOTE LED will again light and the MANUAL
LED will go off.
NOTE:
The modes of operation described in
paragraphs 5.3.3 through 5.3.6 apply ONLY
to KC and Benchmark Series Boilers.
External wiring connections for these modes
are made at the Input/Output (I/O) Box
which is located on the left side of KC
Series units and on the front of Benchmark
Series units.
5.3.3 Indoor/Outdoor Reset Mode
This mode of operation is based on outside air
temperatures. As the outside air temperature
decreases, the supply header temperature will
increase and vice versa. For this mode, it is
necessary to install an outside air sensor as well
as select a building reference temperature and a
reset ratio.
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