Service And Maintenance Procedures - Carrier 59TN6C Installation, Start-Up, Operating, Service And Maintenance Instructions

59TN6C: Installation, Start-up, Operating, Service and Maintenance Instructions
2. When thermometer readings
temperature from supply-air temperature to determine air
temperature rise.
NOTE: The temperatures read by the RAT and SAT sensors connected
to the control board can be displayed during heating and cooling
operation by enabling this feature in the (t°) menu item. See Fig. 60.
Select F for Fahrenheit or C for Celsius. When enabled, the display will
cycle through the current operating mode, SAT, RAT, and temperature
differential. If displayed SAT value does not agree with measured
values, relocate SAT sensor farther away from furnace or after a bend in
the ductwork.
NOTE: Temperature rise can be determined for low-heat and high-heat
operation by locking the furnace in each mode of operations. The mode
of operation is based on the (Htt) setting on the furnace control board.
3. This furnace is capable of automatically providing proper airflow to
maintain the temperature rise within the range specified on furnace
rating plate. If temperature rise is outside this range, proceed as
follows:
a. Check gas input for low- and high-heat operation.
b. Check derate for altitude, if applicable.
c. Check all return and supply ducts for excessive restrictions
causing static pressure greater than 0.5-in. w.c.
To lock the furnace in low heat:
1. On the 3 digit display, navigate to (Htt) and select (2St) to lock the
furnace in low-heat operation. See
If the temperature rise is too high or too low in low heat:
1. Remove jumpers from R and W/W1.
2. Wait until the blower off delay is completed.
3. Remove blower door.
4. Refer to the FURNACE CONTROL PROGRAMMING AND
NAVIGATION section of this manual for instructions on adjusting
the blower speed.
5. Replace blower door.
6. Re-check low heat temperature rise.
To lock the furnace in high heat:
1. Connect a jumper across R and W/W1 and W2 at the thermostat
terminals at the furnace control.
2. Allow the burners to ignite and the blower to turn on.
3. Allow the supply temperature to stabilize and verify the proper rise
range.
If the temperature rise is too high or too low in high heat:
1. Remove jumpers from R and W/W1 and W2.
2. Wait until the blower off delay is completed.
3. Remove blower door.
4. Refer to the FURNACE CONTROL PROGRAMMING AND
NAVIGATION section of this manual for instructions on adjusting
the blower speed.
5. Replace blower door.
6. Re-check high heat temperature rise.
After the temperature rise has been verified:
1. Remove jumpers from thermostat terminals.
2. Allow the blower off delay to complete.
3. On the 3 digit display, navigate to (Htt) and select (1St) or (2St) to
depending on thermostat type. See
4. Proceed to "Adjust Blower Off Delay" or install blower door if
complete.
Check Safety Controls
The flame sensor, gas valve, and pressure switch were all checked in the
Start-up procedure section as part of normal operation.
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
stabilize, subtract return-air
Fig. 60 and Fig. 61.
Fig. 60. and Fig. 61.
1. Check Main Limit Switch
This control shuts off combustion system and energizes
air-circulating blower motor, if furnace overheats. By using this
method to check limit control, it can be established that limit is
functioning properly and will operate if there is a restricted
return-air supply or motor failure. If limit control does not function
during this test, cause must be determined and corrected.
a. Run furnace for at least 5 minutes.
b. Gradually block off return air with a piece of cardboard or sheet
metal until the limit trips.
c. Unblock return air to permit normal circulation.
d. Burners will re-light when furnace cools down.
2. Check Pressure Switch(es)
This control proves operation of the draft inducer blower.
a. Turn off 115-V power to furnace.
b. Disconnect inducer motor lead wires from wire harness.
c. Turn on 115-V power to furnace.
d. Set thermostat to "call for heat" and wait 1 minute. When low
pressure switch is functioning properly, hot surface igniter
should NOT glow and control diagnostic light flashes a status
code (32.2). If hot surface igniter glows when inducer motor is
disconnected shut down furnace immediately, determine reason
pressure switch did not function properly and correct condition.
e. Turn off 115-V power to furnace.
f. Reconnect inducer motor wires, replace door, and turn on 115-V
power.
g. Blower will run for 90 sec before beginning the call for heat
again.
h. Furnace should ignite normally.
Checklist
• Put away tools and instruments. Clean up debris.
• Check Input/Output gas pressure
• Check heat rise per application static pressure
• Cooling CFM per application static pressure
• Verify that blower-OFF delay time is selected as desired.
• Verify that blower and burner access doors are properly installed.
• Cycle test furnace with room thermostat.
• Check operation of accessories per manufacturer's instructions.
• Review User's Guide with owner.
• Attach literature packet to furnace

SERVICE AND MAINTENANCE PROCEDURES

Untrained personnel can perform basic maintenance functions such as
cleaning and replacing air filters. All other operations must be performed
by trained service personnel. A qualified service person should inspect
the furnace once a year.
!
FIRE, INJURY OR DEATH HAZARD
Failure to follow this warning could result in personal injury, death
and/or property damage.
The ability to properly perform maintenance on this equipment requires
certain knowledge, mechanical skills, tools, and equipment. If you do
not possess these, do not attempt to perform any service and
maintenance on this equipment other than those procedures
recommended in the Owner's Manual.
60
WARNING