Service And Maintenance Procedures - Carrier N92ESN Installation, Start-Up, Operating And Service And Maintenance Instructions

N92ESN: Installation, Start-up, Operating and Service and Maintenance Instructions
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.
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 the temperature limit control, it can be established
that the limit is functioning properly and that the limit will operate
if there is a restricted return-air supply or motor failure. If the limit
control does not function during this test, the 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 3. If hot surface igniter glows when inducer motor is
disconnected, shut down furnace immediately.
e. Determine reason low pressure switch did not function properly
and correct condition.
f. Turn off 115-v power to furnace.
g. Reconnect inducer motor wires, replace door, and turn on 115-v
power.
h. Blower will run for 90 sec before beginning the call for heat
again.
i. Furnace should ignite normally.
Checklist
1. Put away tools and instruments. Clean up debris.
2. Verify that the jumper is removed from the TEST/TWIN terminal.
Verify that there is nothing plugged into the PLT connector. (Note:
If there is a jumper connector plugged into PLT, remove it and
discard.) See Fig. 36.
3. Verify that the Blower/Heat Off Delay jumpers are set as desired.
See Fig. 36 and Fig. 70.
4. Verify that the blower (lower door in upflow position) and control
("Main" or upper door in upflow position) doors are properly
installed.
5. Verify that the Status LED heartbeat (bright-dim). If not, check that
the power supply is energized and that the blower door is secure.
See Fig. 70 to interpret diagnostic codes.
6. Cycle test furnace with room thermostat to be sure that it operates
properly with the room thermostat. Check all modes including
Heat, Cool and Fan.
7. Check operation of accessories per manufacturer's instructions.
8. Review Owner's Manual with owner.
9. Attach entire 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.
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
!
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.
!
ENVIRONMENTAL HAZARD
Failure to follow this caution may result in environmental pollution.
Remove and recycle all components or materials (i.e. oil, refrigerant,
control board, etc.) before unit final disposal.
!
ELECTRICAL OPERATION HAZARD
Failure to follow this caution may result in improper furnace operation
or failure of furnace.
Label all wires prior to disconnection when servicing controls. Wiring
errors can cause improper and dangerous operation.
!
ELECTRICAL SHOCK, FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal injury or death,
or property damage.
Before installing, modifying, or servicing system, main electrical
disconnect switch must be in the OFF position and install a lockout tag.
There may be more than one disconnect switch. Lock out and tag
switch with a suitable warning label. Verify proper operation after
servicing. Always reinstall access doors after completing service and
maintenance.
General
These instructions are written as if the furnace is installed in an upflow
application. An upflow furnace application is where the blower is
located below the combustion and controls section of the furnace, and
conditioned air is discharged upward. Since this furnace can be installed
in any of the 4 positions shown in
orientation to component location accordingly.
Electrical Controls and Wiring
Each pressure switch is labeled with the reference location (noted as
"COLLECTOR BOX-LPS" or "HOUSING-HPS" on the switch). The
nominal break point of each switch is shown on the label below the
reference location in inches of water column, "W.C." The maximum and
minimum break point of the switch is +/- 0.05 inches of water column
from the nominal break point of the switch. The maximum make point of
the switch is 0.10 inches of water above the maximum break point of the
switch.
Example: Nominal break point on pressure switch is 0.68-in. W.C. The
minimum break point of the switch is 0.63-in. W.C. The maximum break
point of the switch is 0.73-in. W.C. The maximum make point of the
switch is 0.83-in. W.C.
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WARNING
CAUTION
CAUTION
WARNING
Fig. 2, you must revise your