Sequences Of Operations - Aprilaire 1700 Safety And Installation Instructions Manual

DEHUMIDIFIER SEQUENCE OF OPERATION
IF THE DEHUMIDIFIER IS NOT WIRED TO THE HVAC EQUIPMENT, THE DEHUMIDIFIER WILL SAMPLE AT THE END OF THE
CYCLE PERIOD.
With 3 minutes left in the Cycle Period, the Dehumidifier will turn on the Dehumidifier blower for 2 minutes, during this time the
temperature and relative humidity are measured and the dewpoint is calculated. If the dewpoint is higher than the setting at the
Control Knob then the Dehumidifier will turn on the Dehumidifier compressor and the Dehumidifier will run until it reaches set point.
After reaching the set point, the Dehumidifier will not sample again until the end of the next Sample Period.
For example, if the Sample Period is set for 1 hour, the Dehumidifier will sample at the end of the hour. Once the dehumidifier
reaches set point and shuts off, the dehumidifier will not sample again until the end of the next hour.
IF THE DEHUMIDIFIER IS WIRED INTO THE HVAC EQUIPMENT, THE DEHUMIDIFIER WILL SAMPLE THE FIRST TIME THE HVAC
EQUIPMENT RUNS IN THE CYCLE PERIOD OR AT THE END OF THE CYCLE PERIOD IF THE HVAC EQUIPMENT DOES NOT RUN.
For example, if the Cycle Period is set to 1 hour and the air conditioner starts 15 minutes into that hour, the Dehumidifier will
sample when the air conditioner starts. Once the Dehumidifier begins dehumidifying, it will run until set point is reached. If the
Dehumidifier samples and determines that dehumidification is not needed, it will not sample again until the next Cycle Period.
DAMPER SEQUENCE OF OPERATION
In the Whole House Convertible to Localized installation 4 motorized dampers are used to control the air flow through the
Dehumidifier. The dampers are energized when the HVAC equipment is running. This means that when the HVAC equipment is
running, the dampers are in the Whole-House position. When the HVAC equipment is not running, the dampers are in the local
position.
VENTILATION OR AIR CYCLING SEQUENCE OF OPERATION
If the Model 1700 is providing fresh air ventilation or air cycling, it is monitoring the HVAC equipment to provide the amount of
HVAC blower run time that has been set by the Cycle Time during the Cycle Period.
If a fresh air damper has not been installed then the 1700 is providing air cycling. The Dehumidifier will monitor the HVAC system
and if the system has not run for the specified Cycle Time within the Cycle Period, the Dehumidifier will energize the HVAC
blower through the G terminal to provide the desired amount of blower run time.
For example, if the Cycle Time is set for 10 minutes and the Cycle Period is set for 1 hour then the Dehumidifier will provide 10
minutes of air cycling or fresh air ventilation. If the HVAC system runs for 5 minutes during this hour then the Dehumidifier will
energize the blower for an additional 5 minutes.
If a fresh air damper has been installed, then the Model 1700 is providing fresh air ventilation. The 1700 will open the fresh air
damper whenever the HVAC system is running, up to the amount of time specified by the Cycle Time. The Dehumidifier will
energize the HVAC blower and open the fresh air damper to provide the desired ventilation time if the HVAC system has not run
for the specified Cycle Time.
If an Outdoor Temperature Sensor has been installed, then the Dehumidifier will use the outdoor temperature to determine if the
fresh air damper is opened. If the outdoor temperature is above 100°F the damper will not open. If the temperature is between
20°F and 0°F the damper will only open with a Heat call. If the outdoor temperature is below 0°F the damper will not open. If the
outdoor temperature is not installed then the temperature is not considered in opening the damper.
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