Lennox G61MPV Service Manual page 38

OPERATING
SEQUENCE
System System
Step
Condition
NO CALL FOR DEHUMIDIFICATION
Normal Operation −
1
Y1
Normal Operation −
2
Y2
ROOM THERMOSTAT CALLS FOR FIRST STAGE COOLING
BASIC MODE (only active on a Y1 thermostat demand)
Normal Operation 1
Dehumidification
2
Call
PRECISION MODE (operates independent of a Y1 thermostat demand)
Normal Operation 1
Dehumidification
2
call
Dehumidification
1
call ONLY
ROOM THERMOSTAT CALLS FOR FIRST AND SECOND STAGE COOLING
BASIC MODE (only active on a Y1 thermostat demand)
Normal Operation 1
Dehumidification
2
Call
PRECISION MODE (operates independent of a Y1 thermostat demand)
Normal Operation 1
Dehumidification
2
call
Dehumidification
1
call ONLY
Jumpers at indoor unit with a two stage outdoor unit p
Cut factory jumper from Y1 to Y2 or cut W915 (Y1 to Y2) C t f
With Condensing unit − Cut W914 (R to DS) on SureLight board With Condensing unit − Cut W914 (R to DS) on SureLight board
With Heat Pump − Cut W914 (R to DS) & W951 (R to O) on SureLight board
Dave Lennox SignatureStat to use for this application − 51M27 2 heat / 2 cool or 51M28 − 2 heat / 2 cool for heat pumps
*Normal operation first stage cooling blower speed is 70% of COOL speed.
**In Precision mode, SignatureStats built before 10−2003 will maintain room temperature up to 3°F(1.8°C) cooler than room
setting. SignatureStats built 10−2003 and later will maintain room temperature up to 2 °F (1.2°C) cooler than room setting.
G61MPV, SignatureStatt and TWO STAGE OUTDOOR UNIT
SYSTEM DEMAND
Thermostat Demand
W W
Y1 Y2 O G
1 2
On On On
On On On On
On On On
On On On On
On On On
On On On On
On On On On
On On On On
On On On On
On On On
On On On On
On On On On
t j f Y1 t Y2
TABLE 24
Relative Humidity
Compressor
Status D
24
Acceptable Low
VAC
24
Acceptable High
VAC
24
Acceptable Low
VAC
0
Demand High
VAC
24
Acceptable Low
VAC
0
Demand High
VAC
0
Demand High
VAC
24
Acceptable High
VAC
0
Demand High
VAC
24
Acceptable Low
VAC
0
Demand High
VAC
0
Demand High
VAC
g
t W915 (Y1 t Y2)
Page 38
SYSTEM RESPONSE
Blower Blower
Comments
CFM
(COOL)
70%*
Compressor and indoor
blower follow thermostat blower follow thermostat
demand
100%
70%*
SignatureStat energizes
Y2 and de−energizes D on Y2 and de−energizes D on
a call for de−humidification
70%*
70%*
Dehumidification mode be-
gins when humidity is gins when humidity is
greater than set point
70%*
SignatureStat will try to
maintain room humidity
setpoint by allowing the
70%*
room space to maintain a
cooler room thermostat
setpoint**
100%
SignatureStat energizes
Y2 and de−energizes D on Y2 and de−energizes D on
a call for de−humidification
70%*
70%*
Dehumidification mode be-
gins when humidity is
gins when humidity is
greater than set point
70%*
SignatureStat will try to
70%*
maintain room humidity
setpoint by allowing the setpoint b allo ing the
room space to maintain a room space to maintain a
cooler room thermostat
setpoint** setpoint**