Indoor/Outdoor Startup; Constant Setpoint Mode - Watts Aerco BENCHMARK 750 User Manual

Benchmark 750 – 1000 Boiler User Manual - INTERNATIONAL

5.2.4 Indoor/Outdoor Startup

Startup in the INDOOR/OUTDOOR RESET mode is accomplished as follows:
A design engineer typically provides design outdoor air
temperature and supply header temperature data
1. Refer to the Indoor/Outdoor reset ratio charts in Appendix E.
2. Choose the chart corresponding to the desired Building Reference Temperature.
3. Go down the left column of the chart to the coldest design outdoor air temperature
expected in your area.
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.
Use the ▲ and ▼ arrow keys to select the desired Building Reference Temperature.
8.
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.
Use the ▲ and ▼ arrow keys to select the Reset Ratio determined in step 5.
12.
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. Prior to
changing any temperature-related parameters, other than the setpoint, it is suggested that an
AERCO representative be contacted. For descriptions of temperature-related functions, see
Appendix A; their factory defaults are included in Chapter 3, sections 3.4 – 3.8.
Page 66 of 170
11/03/2016
CHAPTER 5 – MODE OF OPERATION
NOTE
Indoor/Outdoor Startup
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Ph.: 800-526-0288
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