Page 49
CBX40UHV
3.
Cooling Operation
Room thermostat calls
for first
stage?
Air Handler Control (AHC) receives inputs on Y1 terminal.
Y1 terminal on AHC is configured as input and passes
signal from room thermostat to outdoor unit.
Y1 input to the AHC will control the indoor blower
according to the cooling or heating mode blower speed,
ramping and adjust selection jumper pins.
Room thermostat calls
for second stage?
Still calling for first
stage?
Y2 terminal on AHC is
configured as input and
passes signal from room
thermostat to outdoor unit.
Y2 terminal is an
input to the AHC.
The indoor blower
will be controlled
according to the
jumper pin
selections.
Still calling for
second stage?
NOTE - The outdoor unit control
directly controls the outdoor unit
operation.
De-energize Y1 (and O in cooling) terminals on
AHC.
De-energize indoor blower per ramping
profile.
No
Yes
AHC on-board link must be cut between Y1 and Y2 to allow 2 stage cooling operation.
Air Handler Control AHC) Indoor Blower Mode Speed and Profiles
settings
1.
Set
Cooling Mode Blower Speed
jumper pin.
2.
Set
Cooling Mode Blower Ramping
jumper pin.
3.
Set Blower Adjust Selection jumper pin.
Single or Two-Stage Unit
NOTE - The outdoor unit control directly controls the
outdoor unit operation.
De-energize Y2 terminal on AHC.
Indoor blower speed will reset to
Y1 demand.
NOTE - The outdoor unit control directly
controls the outdoor unit operation.
NOTE - The outdoor unit
control directly controls the
outdoor unit operation.
Yes
Yes
Yes
Yes
No
No
CUT ON-BOARD LINK Y1-Y2 FOR
TWO-STAGE A/C
Y1-Y2
2-STAGE
COMPR
R-O
HEAT
PUMP
R-DS
DEHUM
OR
HARMONY
CUT FOR OPTION
RECOMMEND
- USE FIGURE 11 AS A REFERENCE
FOR SETTING JUMPER CONFIGURATIONS ON THE
AIR HANDLER CONTROL.
IMPORTANT
- USE CARE WHEN CUTTING LINKS TO
PREVENT DAMAGE TO CONTROL. SEE FIGURE 11,
CBX40UHV JUMP AND LINK GUIDE FOR FURTHER DETAILS.
Figure 39. Cooling Operation