Component Tests - Carrier 58MTB Service And Maintenance Instructions

Inducer Housing Drain Tube Cap
Fig. 19 - -
Funnel in Drain Tube and Antifreeze
Fig. 20 - -
Running Through Trap
Record the code and repeat the disconnect and reconnect of the red
wire, recording each code until code 11 is displayed indicating no
additional codes. After the last code is displayed or after 2 minutes
in the code recall mode the control will return to normal standby
mode.
Component Test
NOTE:
The furnace control component test allows all
components to run for a short time; except the gas valve and
humidifier terminal HUM are not energized for safety reasons. The
EAC- -1 terminal is energized when blower is energized. This
feature helps diagnose a system problem in case of a component
failure. The component test feature will not operate if any
thermostat signal is present at control and not until all time delays
are completed.
To Begin Component Self-Test:
!
ELECTRICAL
OPERATE HAZARD
Failure to follow this warning could result in electrical shock,
personal injury, or death.
Blower access panel door switch opens 115-v power to control
board. No component operation can occur. Caution must be
A99118
taken when manually closing this switch for service purposes.
1. Remove blower access door.
2. Disconnect thermostat R lead from furnace control.
3. Manually close blower door switch.
4. For approximately 2 sec, short (jumper) the C
minal on control to the TEST/TWIN 3/16-in. quick-connect
terminal on control until LED turns off. Remove jumper
from terminals. (See Fig.16.)
NOTE: If TEST/TWIN and COM- -24v terminals are jumpered
longer than 2 sec, LED will flash rapidly and ignore status code
retrieval request.
Component test sequence for 2-stage furnace is as follows:
a. LED will display previous status code 4 times.
b. Inducer motor starts on high- -speed and continues to run
until Step g of component test sequence.
c. Hot surface igniter is energized for 15 sec, then off.
d. Blower motor operates on LO- -HEAT speed for 10 sec.
e. Blower motor operates on HI- -HEAT speed for 10 sec.
f. Blower motor operates on COOL speed for 10 sec.
g. Inducer motor goes to low- -speed for 10 sec, then stops.
5. Reconnect R lead to furnace control, remove tape from
blower door switch, and re-install blower door.
6. Operate furnace per instruction on outer door.
7. Verify furnace shut down by lowering thermostat setting
A99119 below room temperature.
8. Verify that furnace restarts by raising thermostat setting
above room temperature.
14
WARNING
SHOCK AND UNIT MAY NOT
-24 v ter-
OM