Two-stage variable speed cooling call

What happens, in order

1. Thermostat calls for first-stage cooling
2. Control waits for the compressor off-delay timer to expire
3. First-stage cooling contactor (compressor and fan) is energized
4. Indoor blower starts after a 2 second delay in low cooling mode
5. Second-stage request second-stage contactor is energized and the blower goes to high cooling mode; the control ignores a second-stage request if first stage is not active
6. Second stage satisfied second-stage contactor drops and the blower goes back to low cooling mode
7. First stage satisfied first-stage contactor drops and the blower follows its ramp-down profile selected by the dip switches
8. Blower on and off ramp profiles for low and high cooling are chosen with the blower dip switches

Timings and thresholds

Models

More Lennox furnace sequences

• Single-stage furnace ignition retries and watchguard · Ignition
• Two-stage furnace ignition retries and watchguard · Ignition
• Single-stage furnace gas heating cycle · Heating
• Two-stage furnace heating with single-stage thermostat · Heating
• Two-stage variable speed furnace heating with two-stage thermostat · Heating
• Cooling call on single-stage furnace blower · Cooling
• Continuous fan with heat or cool calls · Standby/shutdown