Component Test; Start-Up Procedures; General; Prime Condensate Trap With Water - Carrier 58MXA Installation, Start-Up, And Operating Instructions Manual

W-and-Y1-and-Y/Y2, or R to W-and-Y1-and-Y/Y2-and-G
circuits are energized the furnace control CPU will switch to
or turn on the blower motor BLWM at HEAT speed, and
begin a heating cycle. The blower motor BLWM will remain
on until the end of the prepurge period, then shut off for 24
seconds then come back on at HEAT speed. When the W input
signal disappears, the furnace control begins a normal inducer
post-purge period and the blower switches to COOL speed
after a 3 second delay. If the R to W-and-Y/Y2-and-G or R to
W-and-Y1-and-Y/Y2-and-G signals disappear at the same
time, the blower motor BLWM will remain on for the selected
blower-OFF delay period. If the R to W-and-Y/Y2 or R to
W-and-Y1-and-Y/Y2 signals disappear, leaving the G signal,
the blower motor BLWM will remain on for the selected
blower-OFF delay period then switch to continuous-blower
speed.
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COMPONENT TEST

NOTE: The furnace control component test allows all compo-
nents to run for a short time; except the gas valve and humidifier
terminal HUM are not energized when the 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 ant the control and not until all
time delays are completed.
To Begin Component Self-Test:
Blower access panel door switch opens 115-v power to
control center. No component operation can occur. Caution
must be taken when manually closing this switch for service
purposes. Failure to follow this warning could result in
electrical shock, personal injury, or death.
1. Remove blower access door.
2. Disconnect the thermostat R lead from furnace control.
3. Manually close blower door switch.
4. For approximately 2 sec, short (jumper) the C
on control to the TEST/TWIN 3/16-inch quick-connect termi-
nal on control until the LED goes out. Remover jumper from
terminals
NOTE: If TEST/TWIN and C
longer than 2 sec, LED will flash rapidly and ignore status code
retrieval request.
Component test sequence is as follows:
a. LED will display previous status code 4 times.
b. Inducer motor starts and continues to run until Step g of
component test sequence.
c. After 7 seconds the hot surface ignitor is energized for 15
sec., then off.
d. Blower motor operates on Continuous-FAN speed for 10
sec.
e. Blower motor operates on HEAT speed for 10 sec.
f. Blower motor operates on COOL speed for 10 sec.
g. Inducer motor 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
below room temperature.
8. Verify that furnace restarts by raising thermostat setting above
room temperature.
-24v terminal
OM
-24v terminals are jumpered
OM

START-UP PROCEDURES

Step 1—General
1. Furnace must have a 115-v power supply properly connected
and grounded. Proper polarity must be maintained for correct
operation.
NOTE: Proper polarity must be maintained for 115-v wiring. If
polarity is incorrect, control center LED status indicator light will
flash rapidly and furnace will not operate.
2. Thermostat wire connections at terminals R, W, G, and Y
must be made at 24-v terminal block on control center.
3. Natural gas service pressure must not exceed 0.5 psig (14-in.
wc), but must be no less than 0.16 psig (4.5-in. wc).
4. Blower access panel must be in place to complete 24-v
electrical circuit to furnace.
These furnaces are equipped with a manual reset limit switch
in burner box. This switch will open if an overheat condition
(rollout) occurs in burner enclosure. Correct inadequate
combustion-air supply or improper venting condition and
reset switch. DO NOT jumper this switch.
Before operating furnace, check each manual reset switch for
continuity. If necessary, press button to reset switch.
Step 2—Prime Condensate Trap With Water
Condensate trap must be PRIMED or proper draining may not
occur. The condensate trap has 2 internal chambers which can
ONLY be primed by pouring water into the inducer drain side
of condensate trap.
1. Remove upper inducer housing drain connection cap. (See
Fig. 55.)
Fig. 55—Inducer Housing Drain Tube
2. Connect field-supplied 1/2-in. ID tube to upper inducer
housing drain connection.
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