AERCO AM Series Boiler User Manual - Manual (Page 56)

AM Series Boilers and Water Heaters
CHAPTER 3 – INSTALLATION
Page 56 of 156 AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 OMM-0100_0B
PRI - 07/14/14
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3.14.2 0-10 VDC Input Connections
– Boilers & Water Heaters
The AM Series models 500, 750 and 1000 are factory supplied with a 0-10 VDC interface (the
399 model can be equipped with one as an option).
This 0-10 VDC interface allows driving the appliance via a 0-10 VDC analog input. To do this,
you must connect the 0-10 VDC supply between terminals 22 and 23 (see Figure 3-21, 3-22,
and 3-23) in the electrical junction box, and the CH mode (parameter 2003 in the Installer Menu
per Section 5.4) must be set to 4 (four). When configured this way, the heater supply
temperature is controlled by the analogic input 0-10 VDC as shown in Figure 3-25 where:
• If the input voltage stays below 1.5V, the heater stays OFF.
• If the input voltage increases to between 1.5V and 2.0V, the heater start to operate and the
supply temperature stays at the value set for the Minimum CH setpoint (parameter 3018 in
the Factory menu per see Appendix B).
• As the input voltage changes between 2V and 10V, the supply temperature will change
proportionally between the Minimum CH setpoint (parameter 3018 in the Factory menu per
see Appendix B) and the Maximum CH setpoint (parameter 3017, in the Factory menu per
see Appendix B).
Figure 3-25: 0-10 VDC Analog Input Algorithm
3.14.3 MODBUS Interface Connections – Boilers and Water Heaters
The AM Series models 500, 750 and 1000 are factory supplied with a MODBUS interface (the
399 model can be equipped with one as an option). This MODBUS interface can be connected
to drive the unit from a building management device. Instructions for its use are supplied on
demand.