Lennox Merit CBX25UHV - Page 20

Page 20
Table 8. Merit
®
CBX25UHV‐048 Air Handler Performance (0 through 0.80 in. w.g. [0 — 200 Pa] External Static Pressure Range)
“ADJUST”
Jumper
Setting
Jumper Speed Positions
“HEAT” Speed First-Stage “COOL” Speed Second-Stage “COOL” Speed
1 2 3 4 1 2 3 4 1 2 3 4
cfm cfm cfm cfm cfm cfm cfm cfm cfm cfm cfm cfm
+ 1450 1670 1880 2340 1050 1200 1340 1650 1440 1670 1950 2340
NORM 1340 1520 1730 2100 950 1100 1230 1520 1325 1530 1740 2150
– 1210 1390 1570 1915 850 1000 1110 1375 1200 1380 1600 1950
NOTES 
The effect of static pressure, filter and electric heater resistance is included in the air volumes listed.
First-stage cooling air volume is 70% of COOL (second-stage) speed setting. Continuous blower speed is approximately 50% of COOL speed setting.
Lennox Harmony III™ Zoning System applications  minimum blower speed is 450 cfm.
Table 9. Merit
®
CBX25UHV‐060 Air Handler Performance (0 through 0.80 in. w.g. [0 — 200 Pa] External Static Pressure Range)
“ADJUST”
Jumper
Setting
Jumper Speed Positions
“HEAT” Speed First-Stage “COOL” Speed Second-Stage “COOL” Speed
1 2 3 4 1 2 3 4 1 2 3 4
cfm cfm cfm cfm cfm cfm cfm cfm cfm cfm cfm cfm
+ 1700 1930 2120 2275 1225 1410 1530 1690 1720 1930 2140 2270
NORM 1570 1760 1925 2100 1120 1260 1400 1540 1580 1765 1970 2100
– 1420 1595 1760 1920 1015 1160 1275 1390 1430 1625 1780 1890
NOTES 
The effect of static pressure, filter and electric heater resistance is included in the air volumes listed.
First-stage cooling air volume is 70% of COOL (second-stage) speed setting. Continuous blower speed is approximately 50% of COOL speed setting.
Lennox Harmony III™ Zoning System applications  minimum blower speed is 450 cfm.
Table 10. Merit
®
CBX25UHV, Thermostat and Single-Stage Outdoor Unit Operating Sequence
Operating Sequence System Demand System Response
System
Condition
Step
Thermostat Demand Relative Humidity
Com
pressor
Air
Handler
CFM
(COOL)
Comments
Y1 Y2 O G W1 W2 Status D
NO CALL FOR DEHUMIDIFICATION
Normal Operation 1 On On On Acceptable 24 VAC High 100%
Compressor and indoor air handler fol
low thermostat demand
BASIC MODE (only active on a Y1 thermostat demand)
Normal
Operation
1 On On On Acceptable 24 VAC High 100%
Thermostat energizes Y1 and de-ener
gizes D on a call for dehumidification
Dehumidification Call 2 On On On Demand 0 VAC High
60%/65
70%*
PRECISION MODE (operates independent of a Y1 thermostat demand)
Normal Operation 1 On On On Acceptable 24 VAC High 100%
Dehumidification mode begins when hu
midity is greater than set point
Dehumidification Call 2 On On On Demand 0 VAC High
60%/65%
70%*
Dehumidification Call
ONLY
1 On On On Demand 0 VAC High
60%/65%
70%*
Thermostat will try to maintain room hu
midity setpoint by allowing the room
space to maintain a cooler room ther
mostat setpoint**
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 COOL cfm for 018, 024, 030; 65% for 036; 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.