AERCO Innovation (G-14-2265 and above) - Manual (Page 31)

Innovation Water Heaters Installation, Operation & Maintenance Manual
CHAPTER 2 – INSTALLATION
OMM-0078_0L
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913
Page 31 of
206
GF-128
Phone: 800-526-0288
PRI: 11/25/2014
2.12.5 ANALOG IN Terminals
The ANALOG IN terminals (+ & -) are used when an external signal is used to change the
setpoint (Remote Setpoint Mode) of the heater.
Either a 4 to 20 mA /1 to 5 VDC or a 0 to 20 mA/ 0 to 5 VDC signal may be used to vary the set-
point or air/fuel valve position. The factory default setting is for 4 to 20 mA / 1 to 5 VDC,
however this may be changed to 0 to 20 mA / 0 to 5 VDC using the Configuration Menu
described in Chapter 3.
If voltage rather than current is selected as the drive signal, a DIP switch must be set on the
PMC Board located inside the C-More Control Box. Refer to Appendix D in C-More Manual GF-
112 for information on setting DIP switches.
All supplied signals must be floating (ungrounded) signals. Connections between the source
and the Heater’s I/O Box must be made using twisted shielded pair of 18–22 AWG wire such as
Belden 9841. Polarity must be maintained and the shield must be connected only at the source
end and must be left floating (not connected) at the Heater’s I/O Box.
Whether using voltage or current for the drive signal, they are linearly mapped to a 40°F to
240°F setpoint or a 0% to 100% air/fuel valve position. No scaling for these signals is provided.
2.12.6 VALVE FEEDBACK Terminals
The Valve Feedback terminals are used when the Sequencing Isolation Valve Feedback option
is selected. The Valve Feedback signal is connected to the “Valve Fdbk” terminals and is used
to confirm that the valve has properly opened or closed. If the Valve Feedback signal does not
match the Valve-Open or Valve-Close command for the time defined in the "Valve Fdbk timer"
entry, the controller will proceed as follows:
(a) If the valve fails with the Valve Stuck Open fault, the “Valve Stuck Open” message will be
displayed and the unit will remain active.
(b) If the valve fails with the Valve Stuck Closed fault, the “Valve Stuck Closed” message will
be displayed and the unit will shut down.
NOTE! If the Valve Feedback option is used, Shorting Jumper #JP2 on the I/O Board Must be
inserted.
2.12.7 SHIELD Terminals
The two SHIELD terminals are used to terminate any shields used on sensor wires connected to
the unit. Only shields must be connected to these terminals.
2.12.8 ANALOG OUT Terminals
The ANALOG OUT terminals (+ & -) output from 0 to 20 mA and may be used to monitor
Setpoint, Outlet Temperature, Valve Position 4-20 mA, Valve Position 0-10v or be set to OFF.
Default setting in the C-More controller is Valve Position 0-10v and settings behave as follows:
1. When 0-10VDC is selected, the voltage output is used by the controller to modulate the
combustion blower via the I/O Box terminals labeled VFD/Blower (Section 2.12.11).
2. If “On Board” Water Heater Management is enabled, the Analog Output terminals are
used to drive the isolation valve, open and closed.
NOTE
When driving an isolation valve, shorting jumper #JP2 MUST be installed
on the I/O Board.