Carrier 58TP0B Installation, Start-Up, Operating And Service And Maintenance Instructions page 46

58TP0B/58TP1B: Installation, Start-up, Operating and Service and Maintenance Instructions
the furnace control CPU can turn on the air conditioning relay ACR to
energize the Y/Y2 terminal and switch the outdoor unit to high-cooling.
The furnace control CPU can start up the cooling unit in either low- or
high-cooling. If starting up in low-cooling, the furnace control CPU
determines the low-cooling on-time (from 0 to 20 minutes) which is
permitted before switching to high-cooling. If the power is interrupted,
the stored history is erased and the furnace control CPU will select
low-cooling for up to 20 minutes and then energize the air conditioning
relay ACR to energize the Y/Y2 terminal and switch the outdoor unit to
high-cooling, as long as the thermostat continues to call for cooling.
Subsequent selection is based on stored history of the thermostat cycle
times.
The wall thermostat "calls for cooling", closing the R-to-G-and-Y
circuits. The R-to-Y1 circuit starts the outdoor unit on low-cooling
speed, and the R-to-G-and-Y1 circuits starts the furnace blower motor
BLWM at low-cooling airflow. Low cooling airflow is based on the low
cooling blower speed (CL1) selection. See
If the furnace control CPU switches from low-cooling to high-cooling,
the furnace control CPU will energize the air conditioning relay ACR.
When the air conditioning relay ACR is energized the R-to-Y1-and-Y2
circuits switch the outdoor unit to high-cooling speed, and the
R-to-G-and-Y1-and-Y/Y2 circuits transition the furnace blower motor
BLWM to high-cooling airflow. High-cooling airflow is based on high
cooling blower speed (CL2) selection. See
The electronic air cleaner terminal EAC-1 is energized with 115 VAC
whenever the blower motor BLWM is operating.
When the thermostat is satisfied, the R-to-G-and-Y circuit are opened.
The outdoor unit stops, and the furnace blower BLWM and electronic air
cleaner terminal EAC-1 will remain energized for an additional 5, 30, or
90 seconds (depending on the cooling blower-OFF delay (Cod) setting).
The furnace CPU is factory set for a 90 second cooling blower-OFF
delay (See Fig. 45).
c. Two-Stage Thermostat and Two-Speed Cooling
See Fig. 30 for thermostat connections
NOTE: (Ctt) setting must be set to (2st) to allow thermostat control
of the outdoor unit staging. (See
The thermostat closes the R-to-G-and-Y1 circuits for low-cooling or
closes the R-to-G-and-Y1-and-Y2 circuits for high-cooling. The
R-to-Y1 circuit starts the outdoor unit on low-cooling speed, and the
R-to-G-and-Y1 circuit starts the furnace blower motor BLWM at
low-cooling airflow based on low cooling blower speed (CL1) selection.
The R-to-Y1-and-Y2 circuits start the outdoor unit on high-cooling
speed, and the R-to- G-and-Y/Y2 circuits start the furnace blower motor
BLWM at high-cooling airflow. High-cooling airflow is based on high
cooling blower speed (CL2) selection (See
The electronic air cleaner terminal EAC-1 is energized with 115 VAC
whenever the blower motor BLWM is operating.
When the thermostat is satisfied, the R-to-G-and-Y1 or R-to-
G-and-Y1-and-Y2 circuits are opened. The outdoor unit stops, and the
furnace blower BLbWM and electronic air cleaner terminal EAC-1 will
remain energized for 5, 30, or 90 seconds (depending on the cooling
blower-OFF delay (Cod) setting). The furnace CPU is factory set for a
90 second cooling blower-OFF delay (See
4. Dehumidification Mode
See Fig. 30 for thermostat connections.
The dehumidification output on the thermostat should be connected
to the furnace control thermostat terminal DHUM. When there is a
dehumidify demand, the DHUM input is activated, which means 24
VAC signal is removed from the DHUM input terminal. In other
words, the DHUM input logic is reversed. The DHUM input is
turned ON when no dehumidify demand exists. Once 24 VAC is
detected by the furnace control on the DHUM input,
dehumidification capability is activated. If the DHUM input is
removed for more than 48 hours, the furnace control reverts back to
non-dehumidification mode.
The cooling operation described in item 3 above also applies to
operation with a dehumidification thermostat. The exceptions are
listed below:
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
Fig. 45.
Fig. 45.
Fig. 45).
Fig. 45).
Fig. 45).
a. Low cooling-When the R-to-G-and-Y1 circuit is closed and
there is a demand for dehumidification, the low cooling airflow
demand is reduced by 10 percent.
b. High cooling-When the R-to-G-and Y/Y2 circuit is closed and
there is a demand for dehumidification, high cooling airflow
demand is reduced by 10 percent.
c. Cooling OFF-delay-When the "call for cooling" is satisfied and
there is a demand for dehumidification, the cooling blower-OFF
delay is decreased from its normal setting based on (Cod) to 5
seconds.
5. Continuous Fan Mode
When the R-to-G circuit is closed by the thermostat, the blower
motor BLWM will operate at continuous fan airflow. Continuous
fan airflow selection is initially based on the CF (continuous fan)
selection shown in Fig.
Terminal EAC-1 is energized as long as the blower motor BLWM is
energized.
During a call for heat, the furnace control CPU will transition the
blower motor BLWM to continuous fan airflow or low-heat airflow
whichever is lowest. The blower motor BLWM will remain ON
until the main burners ignite then shut OFF and remain OFF for the
blower-ON delay (45 seconds in low-heat, and 25 seconds in
high-heat), allowing the furnace heat exchangers to heat up more
quickly, then restarts at the end of the blower-ON delay period at
low-heat or high-heat airflow, respectively.
The blower motor BLWM will revert to continuous-blower airflow
after the heating cycle is completed. In high-heat, the furnace
control CPU will drop the blower motor BLWM to low-heat airflow
during the selected blower-OFF delay period before transitioning to
continuous-blower airflow.
When the thermostat "calls for low-cooling", the blower motor
BLWM will switch to operate at low-cooling airflow. When the
thermostat is satisfied, the blower motor BLWM will operate an
additional 90 seconds at low-cooling airflow before transitioning
back to continuous-blower airflow.
When the thermostat "calls for high-cooling", the blower motor
BLWM will operate at high cooling airflow. When the thermostat is
satisfied, the blower motor BLWM will operate an additional 90
seconds at high-cooling airflow before transitioning back to
continuous-blower airflow. When the R-to-G circuit is opened, the
blower motor BLWM will continue operating for an additional 5
seconds, if no other function requires blower motor BLWM
operation.
The primary continuous fan airflow (CFn) can be selected using the
3-digit display/pushbuttons or via the service tech app. Refer to the
FURNACE CONTROL PROGRAMMING AND NAVIGATION
section of this manual for instructions on adjusting the continuous fan
speed via the control board interface. Alternate continuous fan airflows,
(CF2 and CF3), can only be modified via the service tech app.
Setting Active Continuous Fan Speed
Method 1: If the G input (or FAN switch/setting at the thermostat) is
turned OFF for 1 to 3 seconds and then back ON, the active continuous
fan speed will cycle to the next speed (CFnCF2). Repeating will
change the active continuous fan speed to the next speed (CF2CF3).
Repeating again will set the active continuous fan back to the primary
speed (CFn). This method is intended as a way for home owners to
adjust the continuous fan speed setting from the thermostat depending on
their needs.
Method 2: The active continuous fan speed (CFn, CF2 or CF3) can be
selected via the service tech app.
6. Heat pump
See Fig. 30 for thermostat connections.
When installed with a heat pump, the furnace control automatically
changes the timing sequence to avoid long blower off times during
demand defrost cycles. Whenever W/W1 is energized along with
Y1 or Y/Y2, the furnace control CPU will transition to or bring on
the blower motor BLWM at cooling airflow or low-heat airflow
whichever is lowest. The blower motor BLWM will remain on until
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45. Factory default is shown in Table 11.