Instruction Manual

Benchmark 750/1000 Boiler Installation, Operation & Maintenance Manual
CHAPTER 5 – MODE OF OPERATION
OMM-0082_0J AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 Page 71 of 192
GF-130 Ph.: 800-526-0288 05/21/2014
Table 5-1: Constant Setpoint Mode Settings
Menu Option Setting
Boiler Mode Constant Setpoint
Internal Setpt
Select desired setpoint using ▲ and ▼
arrow keys (40°F to 240°F)
Refer to section 3.3 for detailed instructions on changing menu options.
5.4 REMOTE SETPOINT MODES
The unit’s setpoint can be remotely controlled by an Energy Management System (EMS) or
Building Automation System (BAS). The Remote Setpoint can be driven by a current or voltage
signal within the following ranges:
• 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 driven by a RS-485 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. Contact your local AERCO
representative for details.
In order to enable the Remote Setpoint Mode, the following menu setting must be made in the
Configuration Menu:
Table 5-2: Remote Setpoint Mode Settings
Menu Option Setting
Boiler Mode Remote Setpoint
Remote Signal
4-20mA/1-5V,
0-20mA/0-5V, or Network
Refer to section 3.3 for detailed instructions on changing menu options.
If the Network setting is selected for RS-485 Modbus operation, a valid Comm Address must be
entered in the Setup Menu. Refer to Modbus Communication Manual GF-114 for additional
information.