AERCO Innovation (G-13-1854 and above) - Manual (Page 32)

Innovation Water Heaters Installation, Operation & Maintenance Manual
CHAPTER 2 – INSTALLATION
Page 32 of
196 AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913
OMM-0078_0J
PRI: 11/22/2013
Phone: 800-526-0288
GF-128
2.12.9 RS485 Comm Terminals
The RS485 communication terminals (+, GND, & -) are used when the Innovation Water
Heaters are being controlled by an Energy Management System (EMS) or the C-More Water
Heater Management (WHM) system using Modbus (RS485) communication. The WHM
software required to control up to 8 AERCO Innovation Water Heaters is included in the C-More
Control System used with each Innovation unit.
2.12.10 RS232 Comm Terminals
The RS232 communication terminals (TxD, RxD) are enabled by setting DIP switch 2 (DIP2) on
the I/O Board to RS232 ENABLE position. When enabled these RS232 terminals permit a
laptop computer or other suitable terminal to be connected to the unit. This RS232
communication feature permits viewing or changing of control panel menu options. In addition, it
provides access to data logs showing: Event Time Line, Fault Log and Sensor Log displays.
2.12.11 VFD/BLOWER Terminals
These terminals (0-10 & AGND) send an analog signal to control the blower speed. When any
of the 4-20mA options is selected for the Analog Outputs (Section 2.12.8), the output from the
VFD/Blower terminals is disabled.
2.12.12 Interlock Terminals
The unit offers two interlock circuits for interfacing with Energy Management Systems and
auxiliary equipment such as pumps or louvers or other accessories. These interlocks are called
the Remote Interlock and Delayed Interlock (REMOTE INTL’K IN and DELAYED INTL’K IN in
Figure 2-12). Both interlocks, described below, are factory wired in the closed position.
NOTE
Both the Remote Interlock and Delayed Interlock must be in the closed
position for the unit to fire.
2.12.12.1 REMOTE INTL’K Terminals
The remote interlock circuit is provided to remotely start (enable) and stop (disable) the unit if
desired. The circuit is 24 VAC and comes factory pre-wired closed (jumped).
2.12.12.2 DELAYED INTL’K Terminals
The delayed interlock is typically used in conjunction with the Auxiliary Relay Contacts
described in section 2.12.14. This interlock circuit is located in the purge section of the start
string. It can be connected to the proving device (end switch, flow switch etc.) of an auxiliary
piece of equipment started by the unit’s auxiliary relay. The delayed interlock must be closed for
the heater to fire. If the delayed interlock is connected to a proving device that requires time to
close (make), a time delay (Aux Start On Dly) that holds the start sequence of the unit long
enough for a proving switch to make (close) can be programmed.
Should the proving switch not prove within the programmed time frame, the unit will shut down.
The Aux Start On Dly can be programmed from 0 to 120 seconds. This option is located in the
Configuration Menu (Chapter 3).