58TN0B/58TN1B: Installation, Start–Up, Operating and Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
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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, 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 Fig. 45).
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 Fig. 45).
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 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).
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, the
furnace control operates in dehumidify mode. If the DHUM input is
removed for more than 48 hours, the furnace control reverts back to
non-dehumidify mode.
The cooling operation described in item 3. above also applies to
operation with a dehumidification thermostat. The exceptions are
listed below:
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 current setting to 5 seconds.
5. Super-Dehumidify Mode
Super-Dehumidify mode can only be entered if the furnace control
is in the Dehumidify mode and there is a demand for
dehumidification. The cooling operation described in item 3. above
also applies to operation with a dehumidification thermostat. The
exceptions are listed below:
a. When the R-to-Y1 circuit is closed, R-to-G circuit is open, and
there is a demand for dehumidification, the furnace blower motor
BLWM will drop the blower airflow to 65 percent of low-cooling
airflow for a maximum of 10 minutes each cooling cycle or until
the R-to-G circuit closes or the demand for dehumidification is
satisfied.
b. When the R-to-Y/Y2 circuit is closed, R-to-G circuit is open, and
there is a demand for dehumidification, the furnace blower motor
BLWM will drop the blower airflow to 65 percent of
high-cooling airflow for a maximum of 10 minutes each cooling
cycle or until the R-to-G circuit closes or the demand for
dehumidification is satisfied. High-cooling airflow is based on
high cooling blower speed (CL2) selection, see Fig. 45.
c. When the “call for cooling” is satisfied and there is a demand for
dehumidification, the cooling blower-off delay is decreased from
current setting to 5 seconds.
6. 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. 45. Factory default is shown in Table 13.
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 sec in low-heat, and 25 sec 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 fan 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 fan 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 sec 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 sec
at high-cooling airflow before transitioning back to continuous fan
airflow. When the R-to-G circuit is opened, the blower motor
BLWM will continue operating for an additional 5 sec, 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 blower 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 (CFnCF2). Repeating will
change the active continuous fan speed to the next speed (CF2CF3).
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.
7. 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
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