Carrier 58TP1A Installation, Start-Up, Operating And Service And Maintenance Instructions page 43

58TP0A/58TP1A: Installation, Start-up, Operating and Service and Maintenance Instructions
non-Thermidistat mode.
The cooling operation described in item 3. above also applies to
operation with a Thermidistat. 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 furnace blower motor
BLWM will drop the blower airflow to 90 percent of low-cooling
airflow which is the true on-board CF selection. (See
and Fig. 55).
b. High cooling-When the R-to-G-and Y/Y2 circuit is closed and
there is a demand for dehumidification, the furnace blower motor
BLWM will drop the blower airflow to 90 percent of
high-cooling airflow. High-cooling airflow is based on the A/C
(air conditioning) selection. (See
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 90 seconds to 5 seconds.
5. Continuous Blower Mode
When the R-to-G circuit is closed by the thermostat, the blower
motor BLWM will operate at continuous blower airflow.
Continuous blower airflow selection is initially based on the CF
selection shown in Table 12
in Table 12. 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
blower 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.
Continuous Blower Speed Selection from Thermostat
To select different continuous-blower airflow from the room thermostat,
momentarily turn off the FAN switch or push button on the room
thermostat for 1-3 seconds after the blower motor BLWM is operating.
The furnace control CPU will shift the continuous-blower airflow from
the factory setting to the next highest CF selection airflow. (See
and Fig. 55). Momentarily turning off the FAN switch again at the
thermostat will shift the continuous-blower airflow up one more
increment. If you repeat this procedure enough you will eventually shift
the continuous-blower airflow to the lowest CF selection. (See
and Fig. 55). The selection can be changed as many times as desired and
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
Table 12
Fig. 55).
and Fig. 55. Factory default is shown
Table 12
Table 12
is stored in the memory to be automatically used following a power
interruption.
NOTE: If the blower-off delay is set to the maximum, the adjustable
continuous-fan feature is locked (i.e., fan speed cannot be changed from
its current setting).
6. Heat pump
See Fig. 30 - Fig. 33 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
the main burners ignite then shut OFF and remain OFF for 25
seconds before coming back on at heating airflow. When the W/W1
input signal disappears, the furnace control begins a normal inducer
post-purge period while changing the blower airflow. If Y/Y2 input
is still energized the furnace control CPU will transition the blower
motor BLWM airflow to cooling airflow. If Y/Y2 input signal
disappears and the Y1 input is still energized the furnace control
CPU will transition the blower motor BLWM to low-cooling
airflow. If both the Y1 and Y/Y2 signals disappear at the same time,
the blower motor BLWM will remain on at low-heat airflow for the
selected blower-OFF delay period. At the end of the blower- OFF
delay, the blower motor BLWM will shut OFF unless G is still
energized, in which case the blower motor BLWM will operate at
continuous blower airflow.
7. Component test
The furnace features a component test system to help diagnose a
system problem in the case of a component failure. To initiate the
component test procedure, ensure that there are no thermostat
inputs to the control and all time delays have expired. Turn on setup
switch SW1-6. (See Fig.
NOTE: The component test feature will not operate if the control is
receiving any thermostat signals or until all time delays have expired.
The component test sequence is as follows:
a. The furnace control CPU turns the inducer motor ON at
high-heat speed and keeps it ON through step c.
b. After waiting 10 seconds the furnace control CPU turns the hot
surface igniter ON for 15 seconds, then OFF.
c. The furnace control CPU then turns the blower motor BLWM on
at 50 percent torque for 15 seconds, then OFF.
d. After shutting the blower motor OFF the furnace control CPU
switches the inducer to low-heat speed for 10 seconds, then OFF.
NOTE: The EAC terminals are energized when the blower is operating.
After the component test is completed, 1 or more status codes 11 or 25
will flash. See component test section or Service Label
explanation of status codes.
NOTE: To repeat component test, turn setup switch SW1-6 to OFF and
then back ON.
Wiring Diagram
Refer to Fig. 59 for wiring diagram.
Troubleshooting
Refer to the service label (see
information. Also, the Troubleshooting Guide (see
useful tool in isolating furnace operation problems. Beginning with the
word "Start," answer each question and follow the appropriate arrow to
the next item. The Guide will help to identify the problem or failed
component. After replacing any component, verify correct operation
sequence.
43
36).
(Fig.
Fig. 53) for some troubleshooting
Fig. 60) can be a
53) for