AERCO RECON 1000 - Manual (Page 34)

RECON Water Heaters Installation, Operation & Maintenance Manual
CHAPTER 2 – INSTALLATION
Page 34 of 178 AERCO International, Inc.  100 Oritani Dr.  Blauvelt, NY 10913 OMM-0103_0A
PRI: 10/28/2014 Phone: 800-526-0288 GF-147
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 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 Water Heater Management option is enabled, a jumper must
be inserted on #JP3 on the I/O Board (see Figure 2-14).
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,
below).
2) If “On Board” Water Heater Management is enabled, the Analog Output terminals are
used to drive the isolation valve, open and closed.
3) When the 4-20mA is selected for the Analog Output, the 0-10VDC is disabled at the
VFD/Blower terminals, and the selected output is available at the terminals labeled
Analog Output +/-.