Lennox CBX25UHV Series Installation And Service Procedure page 8

Table 7. CBX25UHV‐048 Air Handler Performance (0 through 0.80 in. w.g. External Static Pressure Range)
HEAT Speed
ADJUST
1 2
Jumper
cfm cfm
Setting
+ 1450 1670
NORM 1340 1520
- 1210 1390
NOTES - The effect of static pressure, filter and electric heater resistance is included in the air volumes listed.
. . . . . . . . First-stage cooling air volume is approximately 70% of the second-stage COOL speed setting.
. . . . . . . . Continuous fan speed is approximately 50% of second-stage COOL speed setting.
®
. . . . . . . . Lennox Harmony III Zone Control Applications - Minimum air handler speed is approximately 450 cfm.
Table 8. CBX25UHV‐060 Air Handler Performance (0 through 0.80 in. w.g. External Static Pressure Range)
HEAT Speed
ADJUST
1 2
Jumper
Setting cfm cfm
+ 1700 1930
NORM 1570 1760
- 1420 1595
NOTES - The effect of static pressure, filter and electric heater resistance is included in the air volumes listed.
. . . . . . . . First-stage cooling air volume is approximately 70% of the second-stage COOL speed setting.
. . . . . . . . Continuous fan speed is approximately 50% of second-stage COOL speed setting.
®
. . . . . . . . Lennox Harmony III Zone Control Applications - Minimum air handler speed is approximately 450 cfm.
Table 9. CBX25UHV, Thermostat and Single-Stage Outdoor Unit Operating Sequence
Operating Sequence
System
Step
Condition
NO CALL FOR DEHUMIDIFICATION
Normal
1
Operation
BASIC MODE (only active on a Y1 thermostat demand)
Normal
1
Operation
Dehumidification
2
Call
PRECISION MODE (operates independent of a Y1 thermostat demand)
Normal
1
Operation
Dehumidification
2
call
Dehumidification
1
call ONLY
Jumpers at indoor unit with a single stage outdoor unit
With Condensing unit - Y1 to Y2 and R to O
With Heat Pump - Y1 to Y2
* During dehumidification, cooling air handler speed is as follows: 70% of second-stage COOL cfm for 018, 024, 030, 65% for 036 and 60% for 042, 048 and
060 units.
** Thermostat will maintain the room temperature up to 2°F (1.2°C) cooler than the room thermostat setting in precision mode.
3 4
cfm cfm cfm
1880 2340 1050
1730 2100 950
1570 1915 850
3 4
cfm cfm cfm
2120 2275 1225
1925 2100 1120
1760 1920 1015
System Demand
Thermostat Demand
Y1 Y2 O G W1 W2
On On On
On On On
On On On
On On On
On On On
On On On
BDC3 Jumper Speed Positions
First-Stage COOL Speed
1 2 3
cfm cfm
1200 1340
1200 1230
1000 1100
BDC3 Jumper Speed Positions
First-Stage COOL Speed
1 2 3
cfm cfm
1410 1530
1260 1400
1160 1275
Relative Humidity
Status D
Acceptable 24 VAC
Acceptable 24 VAC
Demand 0 VAC
Acceptable 24 VAC
Demand 0 VAC
Demand 0 VAC
Page 8
Second-Stage COOL Speed
4 1 2
cfm cfm cfm
1650 1440 1670
1520 1325 1530
1375 1200 1380
Second-Stage COOL Speed
4 1 2
cfm cfm cfm
1690 1720 1930
1540 1580 1765
1390 1430 1625
System Response
Air
Com­
Handler
Comments
pressor CFM
(COOL)
Compressor and indoor
High 100% air handler follow thermo­
stat demand.
High 100%
Thermostat energizes Y1
and de-energizes D on a
60%/65
call for dehumidification.
High
70%*
High 100%
Dehumidification mode
begins when humidity is
60%/65%
greater than set point.
High
70%*
60%/65% Thermostat will try to
High
70%*
maintain room humidity
setpoint by allowing the
room space to maintain a
cooler room thermostat
setpoint.**
3 4
cfm cfm
1950 2340
1740 2150
1600 1950
3 4
cfm cfm
2140 2270
1970 2100
1780 1890