42
CNT-SVX07D-EN
Sequence of operations
•
Valves are driven open to allow water to flow through the coil
•
Fan is off
•
Face-and-bypass damper (when present) is at full bypass
•
Economizing is disabled
•
The outdoor/return air damper is closed
•
DX cooling is off
•
Electric heat stages are off
Freeze protection (discharge air temperature low limit)
The controller monitors the discharge air temperature with a 10 k
Ω
thermistor wired to analog
input AI2. The freeze-protection operation is initiated whenever the discharge air temperature falls
below the Discharge Air Temperature Low Limit. The Discharge Air Temperature Low Limit is
configurable using the Rover service tool. During freeze protection, the controller increases the
heating capacity or decreases the cooling capacity in order to raise the discharge air temperature
above the low limit. If the discharge air temperature remains below the low limit for 3 minutes, the
controller generates a Discharge Air Temp Limit diagnostic. See
for the effects of this
diagnostic on outputs.
Содержание Tracer ZN521
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