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Benchmark 2500DF-3000DF Installation, Operation & Maintenance Manual
4. Once the design outdoor air temperature is chosen, go across the chart to the desired
supply header temperature for the design temperature chosen in step 3.
5. Next, go up that column to the Reset Ratio row to find the corresponding reset ratio.
6. Access the Configuration Menu and scroll through it until the display shows Bldg Ref
Temp. (Building Reference Temperature). If necessary, refer to section 3.3 for detailed
instructions on menu changing.
7. Press the CHANGE key. The display will begin to flash.
8. Use the ▲ and ▼ arrow keys to select the desired Building Reference Temperature.
9. Press ENTER to save any changes.
10. Next, scroll through the Configuration Menu until the display shows Reset Ratio.
11. Press the CHANGE key. The display will begin to flash.
12. Use the ▲ and ▼ arrow keys to select the Reset Ratio determined in step 5.
13. Press ENTER to save the change.
5.3 CONSTANT SETPOINT MODE
The Constant Setpoint mode is used when a fixed header temperature is desired. Common uses of this
mode of operation include water source heat pump loops, and indirect heat exchangers for potable hot
water systems or processes.
No external sensors are required to operate in this mode. While it is necessary to set the desired setpoint
temperature, it is not necessary to change any other temperature-related functions. The unit is factory
preset with settings that work well in most applications.
parameters, other than the setpoint, it is suggested that an AERCO representative be contacted. For
descriptions of temperature-related functions and their factory defaults, see Appendices A and E.
5.3.1 Setting the Setpoint
The setpoint temperature of the unit is adjustable from 40°F to 240°F. To set the unit for operation in the
Constant Setpoint Mode, the following menu settings must be made in the Configuration Menu:
Menu Option
Boiler Mode
Internal Setpt
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
Page 70 of 234
05/21/2014
CHAPTER 5 – MODE OF OPERATION
Indoor/Outdoor Startup – Continued
Setting
Constant Setpoint
Select desired setpoint using ▲ and ▼ arrow keys (40°F to 240°F)
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913
Phone: 800-526-0288
Prior to changing any temperature-related
OMM-0099_0A
GF-145
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