Air Handler Performance Table - Lennox Merit CBX25UHV Installation Instructions Manual

speed position #4 is 1000 CFM. The + adjustment setting for
that position is 1080 CFM and for the - adjustment setting is
910 CFM. After the adjustment setting has been determined,
choose the remaining speed jumper settings from those
offered in the table in that row.
The TEST pin is available to bypass the BDC3 control and
run the motor at approximately 70% to test that the motor is
operational. This is beneficial primarily in troubleshooting.
G must be energized for motor to run.
COOL JUMPER
The COOL jumper is used to determine the CFM during
either cooling or heat pump operation without a call for
electric heat. These jumper selections are activated for
cooling when Y2 and DS terminals in the Merit
CBX25UHV are energized. The are activated for heating
when Y2 is energized.
Applications without the Lennox ComfortSense
thermostat will provide 70% of the COOL CFM during
first-stage cooling for two-stage outdoor units. 100% of
COOL speed is provided for systems with a single-stage
outdoor unit.
Applications with the Lennox ComfortSense
®
Table 3. Merit CBX25UHV‐018 Air Handler Performance (0 through 0.80 in. w.g. [0 — 200 Pa] External Static Pressure Range)
"ADJUST"
Jumper
Setting
+
NORM
–
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 250 cfm.
®
Table 4. Merit CBX25UHV‐024 Air Handler Performance (0 through 0.80 in. w.g. [0 — 200 Pa] External Static Pressure Range)
"ADJUST"
Jumper
Setting
+
NORM
–
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 250 cfm.
®
®
"HEAT" Speed
1 2 3
cfm cfm cfm
470 670 890 1080
440 615 810 1000
400 560 730
"HEAT" Speed
1 2 3
cfm cfm cfm
470 690 900 1120
430 640 810 1020
410 550 720
thermostat, but no demand for de-humidification will
operate as follows: during a first-stage cooling call
(two-stage outdoor unit), the air volume is 70% of the
COOL jumper selection. This arrangement provides for
additional dehumidification during standard first-stage
cooling. See the tables that follow for various scenarios
concerning use of the ComfortSense
and the Merit
For applications with Harmony III
handler CFM volume is determined by the Harmony III
control center.
predetermined at 250 CFM for -018, -024, -030 and -036
units and 450 CFM for -042, -048 and -060 units. This
speed is not adjustable. See footnotes in the blower
®
performance tables.
With the thermostat set for Continuous Fan and without a
call for heating or cooling, the Merit
7000 50% of the COOL CFM selected.
NOTE - For two-stage heat pumps, air handler will operate
at 70% of the COOL selection until supplemental electric
heat is demanded. At that time, the air handler will operate
at the selected HEAT speed. This arrangement provides
7000 warmer supply air during second-stage heating.
Jumper Speed Positions
First-Stage "COOL" Speed
4 1 2
cfm cfm cfm
350 470
350 450
910 350 420
Jumper Speed Positions
First-Stage "COOL" Speed
4 1 2
cfm cfm cfm
350 470
330 450
900 300 405
Page 18
®
CBX25UHV series unit.
®
The minimum
®
Second-Stage "COOL" Speed
3 4 1
cfm cfm cfm
620 760 470
560 700 435
520 650 400
Second-Stage "COOL" Speed
3 4 1
cfm cfm cfm
625 775 480
580 720 430
505 650 390
®
7000 thermostat
zone control, the air
blower speed is
CBX25UHV provides
2 3 4
cfm cfm cfm
675 890 1090
610 815 1020
575 725 915
2 3 4
cfm cfm cfm
670 890 1125
605 820 1020
545 740 930