Lennox International Inc Lennox Air Handler Airflow - Cooling Blower Speed, Change Blower Speed

Models: Merit CBX25UH Series Lennox Air Handler

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Airflow — Cooling Blower Speed

THERMOSTAT

AIR HANDLER

 

 

 

 

 

R

 

 

THERMOSTAT

AIR HANDLER

 

 

G

 

 

 

R

 

 

 

 

 

 

 

SEE

 

BU

 

 

G

 

 

 

 

 

 

NOTE

 

 

SEE

 

BU

 

 

 

 

 

 

 

 

 

NOTE

 

W

 

 

 

 

 

 

 

 

Y

 

 

 

 

 

 

 

 

 

HEAT‐ONLY APPLICATION

 

 

 

AIR

 

 

 

 

 

 

CONDITIONER

THERMOSTAT

 

 

HEAT PUMP

 

 

UNIT

 

 

AIR HANDLER

UNIT

 

 

 

 

 

 

 

COOLING‐ONLY APPLICATION

 

 

R

 

 

 

 

 

 

 

THERMOSTAT

AIR HANDLER

 

 

G

 

 

R

 

 

 

 

 

 

 

 

 

 

 

G

 

CONNECT COMMON

 

BU

 

 

 

WIRE ONLY IF

 

 

 

 

 

 

 

 

 

REQUIRED

 

 

 

 

 

 

 

 

 

 

 

W

(REFER TO THE

 

 

 

 

 

APPROPRIATE

 

 

 

 

 

 

THERMOSTAT

 

BK

 

 

 

BK

INSTALLATION

 

 

 

 

INSTRUCTIONS)

 

 

 

 

 

 

 

 

 

SEE

 

BU

 

 

W

 

Y

 

 

 

 

NOTE

 

 

 

 

 

 

 

 

 

 

 

 

AIR CONDITIONER

 

HEAT PUMP APPLICATION WITH

 

 

 

 

 

ELECTRIC HEAT

 

 

 

UNIT

 

 

 

 

 

 

 

 

 

 

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 .

CHANGE BLOWER SPEEDWARNING

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.

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.

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Lennox International Inc Lennox Air Handler, Merit CBX25UH Series Airflow - Cooling Blower Speed, Change Blower Speed