Airflow - Cooling Blower Speed - Lennox Merit CBX25UH Series Installation Instructions Manual

THERMOSTAT
R
G
SEE
NOTE
Y
COOLING‐ONLY APPLICATION
THERMOSTAT
R
G
SEE
Y
NOTE
COOLING APPLICATION WITH
ELECTRIC HEAT
NOTE - Connect common wire only if required (Refer to the appropriate thermostat installation instructions)
Figure 12. Low Voltage Connections (3-Speed PSC Motor) - Field Wiring
Airflow — Cooling Blower Speed
The cooling blower speed is factory configured to provide
correct airflow for an outdoor unit that matches the cooling
capacity rating of the air handler.
If the outdoor unit is smaller than the maximum cooling
capacity rating for the air handler, the cooling blower speed
may need to be changed. Refer to blower performance
chart, table 2 on page 11 .
WARNING
Electric shock hazard! - Disconnect all
power supplies before servicing.
Replace all parts and panels before op­
erating.
Failure to do so can result in death or elec­
trical shock.
AIR HANDLER
BU
AIR
CONDITIONER
UNIT
AIR HANDLER
CONNECT COMMON
WIRE ONLY IF
(REFER TO THE
W
APPROPRIATE
THERMOSTAT
INSTALLATION
BK
INSTRUCTIONS)
BU
AIR CONDITIONER
UNIT
THERMOSTAT
SEE
NOTE
THERMOSTAT
REQUIRED
CHANGE BLOWER SPEED
1. Disconnect all power supplies.
2. Remove the air handler access panel.
3. Locate pin number 2 on the blower relay. Two black
wires are connected to this terminal pin. One connects
to pin number 5 on the blower relay, one connects to
an in-line splice connecting to a red wire.
4. Remove the wire going to the 4-pin blower motor
connector from the splice.
5. Connect the blower lead [Red (LO), Black (HI)] onto
the splice from the 4-pin blower motor connector.
NOTE — Reuse the factory-installed plastic cap on
whichever wire is not used.
6. Replace all panels.
7. Reconnect power.
Page 10
AIR HANDLER
R
G
BU
W
HEAT‐ONLY APPLICATION
AIR HANDLER
R
G
BU
BK
W
HEAT PUMP APPLICATION WITH
ELECTRIC HEAT
HEAT PUMP
UNIT