Cooling Operation - Lennox LHT/LDT024 Installation Instructions Manual

Cooling Operation

A-Two-Stage Thermostat
1-Economizer With Outdoor Air Suitable
Y1 Demand -
Compressor Off
Blower Low
Dampers Modulate
Y2 Demand -
Compressor On (024 units only)
Compressor Low (036-060)
Blower High
Dampers Full Open
Note - Compressor is energized after damper has been
at full open for three minutes.
2-No Economizer or Outdoor Air Not Suitable
Y1 Demand -
Compressor On (024 units only)
Compressor Low (036-060)
Blower Low
Dampers Minimum Position
Y2 Demand -
Compressor On (024 units only)
Compressor High (036-060)
Blower High
Dampers Minimum Position
B-Three-Stage Thermostat OR Room Sensor
1-Economizer With Outdoor Air Suitable
Y1 Demand -
Compressors Off
Blower Low
Dampers Modulate
Y2 Demand -
Compressor On (024 units only)
Compressor Low (036-060)
Blower High
Dampers Full Open
Note - Compressor is energized after damper has been
at full open for three minutes.
Y3 Demand -
Compressor On (024 units only)
Compressor High (036-060)
Blower High
Dampers Full Open
2-No Economizer or Outdoor Air Not Suitable
Y1 Demand -
Compressor On (024 units only)
Compressor Low (036-060)
Blower Low
Dampers Minimum Position
Y2 Demand -
Compressor On (024 units only)
Compressor High (036-060)
Blower High
Dampers Minimum Position
Y3 Demand -
Compressor On (024 units only)
Compressor High (036-060)
Blower High
Dampers Minimum Position
High speed compressor cooling operation:
RTU MENU > COMPONENT TEST > COOLING >
COOLING STAGE 2
Low speed compressor cooling operation:
RTU MENU > COMPONENT TEST > COOLING >
COOLING STAGE 1
Note - For 024 units, either menu path will result in
single-speed output.
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LHT/LDT024, 036, 048, 060