Adjustments - Carrier 58CTA Installation And Service Instructions Manual

SETUP
SWITCH NO.
SW-1 Adaptive Heat Mode
SW-2
SW-3
2. Check gas lines for leaks.
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in electrical shock,
personal injury, or death.
Blower access door switch opens 115-v power to control. No
component operation can occur unless switch is closed.
Caution must be taken when manually closing this switch for
service purposes.
3. To Begin Component Self-Test:
Remove blower access door. Disconnect the thermostat R lead
from furnace control board. Manually close blower door
switch. Short (jumper) for approximately 2 sec the C
terminal on control to the TEST/TWIN 3/16-inch quick-
connect terminal on control until the LED goes out. Remove
jumper from terminals. (See Fig. 32 and Table 8.)
NOTE: The furnace control allows all components, except the gas
valve, to be run for short period of time. This feature helps
diagnose a system problem in case of a component failure.
Component test feature will not operate if any thermostat signal is
present at the control.
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Refer to service label attached to furnace or See Fig. 55.
Component test sequence 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.
h. Reconnect R lead to furnace control board, remove tape
from blower door switch and re-install blower door.
4. Operate furnace per instruction on inner door.
5. Verify furnace shut down by lowering thermostat setting
below room temperature.
6. Verify furnace restarts by raising thermostat setting above
room temperature.
Table 8—2 Stage Furnace Setup Switch Description
SWITCH NORMAL
NAME POSITION
Blower OFF delay ON or OFF
Blower OFF delay ON or OFF
When OFF, allows 2-stage operation with a single stage thermostat.
Turn ON when using 2 stage thermostat to allow Low Heat opera-
OFF
tion when R to W/W1 closes and High Heat operation when R to
Control blower OFF delay time. Used in conjunction with SW-3
Control blower OFF delay time. Used in conjunction with SW-2
Step 3—Adjustments
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FIRE HAZARD
Failure to follow this warning could result in reduced furnace
life, property damage, injury, and death.
DO NOT bottom out gas valve regulator adjusting screw.
This can result in unregulated manifold pressure and result in
excess overfire and heat exchanger failures.
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FURNACE DAMAGE HAZARD
Failure to follow this caution may result in reduced furnace
life.
-24v
DO NOT redrill orifices. Improper drilling (burrs, out-of-
OM
round holes, etc.) can cause excessive burner noise and
misdirection of burner flames. This can result in flame
impingement of heat exchangers, causing failures. (See Fig.
48.)
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Furnace gas input rate on rating plate is for installations at altitudes
up to 2000 ft. Furnace input rate must be within ±2 percent of
furnace rating plate input. For altitudes above 5500 ft., a field-
supplied high altitude pressure switch is required.
1. Determine the correct gas input rate.
In the U.S.:
The input rating for altitudes above 2,000 ft. must be reduced
by 4 percent for each 1,000 ft. above sea level.
For installations below 2000 ft., refer to the unit rating plate.
For installations above 2000 ft., multiply the input on the
rating plate by the de-rate multiplier in Table 9 for the correct
input rate.
EXAMPLE:
88,000 BTUH INPUT FURNACE INSTALLED AT 4300 FT.
Furnace Input Rate
at Sea Level
88,000
In Canada:
The input rating must be reduced by 10 percent for altitudes of
2,000 ft. to 4,500 ft. above sea level by an authorized Gas
Conversion Station or Dealer. To determine correct input rate
for altitude, see example and use 0.90 as derate multiplier
factor.
2. Determine the correct orifice and manifold pressure adjust-
ment. All models in all positions except Low NOx models in
downflow and horizontal positions use Table 13 (22,000
BTUH per burner).
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DESCRIPTION
OF USE
W/W1 and W2 close.
See Table 12.
See Table 12.
Derate Furnace Input Rate
X Multiplier = at Installation
Factor Altitude
X 0.90 = 79,200