Carrier 58SP0A, Installation, Start-Up, Operating And Service And Maintenance Instructions

Page: 41 / 44

58SP0A/58SP1A: 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.
41
The blower motor BLWM will revert to continuous-blower airflow after
the hea ting cycle is completed.
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 as shown in
Table 13 and Fig. 46 . 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 as shown in
Table 13 and Fig. 46 . The selection can be changed as many times as
desired and 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).
5. Heat pump
See Fig. 28 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.
6. 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. 45 .
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 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.
NOTE: The EAC terminals are energized when the blower is operating.
After the component test is completed, status code 11 will show. See
component test section or Service Label ( Fig. 43 ) for 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. 44 for wiring diagram.
Troubleshooting
Refer to the service label (see Fig. 43 ). The Troubleshooting Guide (see
Fig. ) can be a 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.