Lennox L7742U Programming And Application Manual page 24

Stage Delay & Differential Settings (installer settings)
H/C STGS LOCKED IN default NO (heat/cool stages are turned off
separately). If changed to YES, heat/cool stages are turned off together
(see figures 7 through 14). Scroll to H/C STGS LOCKED IN; press EN-
TER. Use arrows to select between NO or YES. Press SAVE.
H/C STGS LOCKED IN
DEFAULT (NO) YES
STG2 HP LOCK TEMP default OFF (heat pump stage 2 operates
normally). Use this setting in dual fuel applications to lock in the 2nd
stage compressor when the outdoor temperature is at or less than the
LOCK TEMP set point. Scroll to STG2 HP LOCK TEMP; press ENTER.
Use arrows to select a LOCK TEMP between −40 and 75ºF. Press
SAVE.
STG2 HP LOCK TEMP
DEFAULT (OFF) 25°F
H/C
Stages
Locked =
NO
H/C
Stages
Locked =
YES
SET-
POINTS:
506061−01 06/08
1st stage
OFF
2nd stage
1st stage
OFF
2nd stage
OFF
SP −1.5 SP −1.0 SP −0.5
Figure 7. Cooling − 1 or 2 stages
(continued)
Configuration
Multi−stage Cooling for Heat Pump/Non−Heat Pump
Heating − Non−Heat Pump (1 or 2 stages)
Heating − Heat Pump with NO backup heat
Heating − Heat Pump w/electric heat (2−stage: 1compr/1backup)
Heating − Heat Pump w/electric heat (3 stage: 2compr/1backup)
Heating − Heat Pump w/electric heat (3 stage: 1compr/2backup)
Heating − Heat Pump w/electric heat (4 stage: 2compr/2backup)
Heating − dual fuel (2−stage: 1compr/1backup)
Heating − dual fuel (3 stage: 1compr/2backup)
Heating − dual fuel (3 stage: 2compr/1backup)
Heating − dual fuel (4 stage: 2compr/2backup)
1st stage
ON
Stg1 Differential
OFF
Stg2 Differential
1st stage
ON
Stg1 Differential
Stg2 Differential
SP +0.5 SP +1.0
SP
Page 24
2nd stage
ON
2nd stage
ON
SP +1.5 SP +2.0
Figure
7
8
8
8
9
9
10
11
12
13
14