Service And Maintenance Procedures - Carrier 58SB0B Operating Instructions Manual

58SB0B/58SB1B: Installation, Start–Up, Operating and Service and Maintenance Instructions
WARNING
!
FURNACE OVERHEATING HAZARD
Failure to follow this caution may result in reduced furnace life.
Recheck temperature rise. It must be within limits specified on the
rating plate. Recommended operation is at the mid-point of rise range
or slightly above.
6. Adjust heating blower-OFF delay. The blower-OFF delay has four
adjustable settings from 90 sec to 180 sec. Refer to the FURNACE
CONTROL PROGRAMMING AND NAVIGATION section of
this manual for instructions.
Factory off delay setting is 120 sec.
7. Set airflow CFM for cooling. See
filter).
8. Adjust cooling blower-OFF delay. Refer to the FURNACE
CONTROL PROGRAMMING AND NAVIGATION section of
this manual for 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(es)
This control shuts off combustion control 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 duct
system 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 draft safeguard switch.
The purpose of this control is to cause the safe shutdown of the
furnace during certain blocked vent conditions.
a. Verify vent pipe is cool to the touch.
b. Disconnect power to furnace and remove vent connector from
furnace vent elbow.
c. Restore power to furnace and set room thermostat above room
temperature.
d. After normal start-up, allow furnace to operate for 2 minutes,
then block vent elbow in furnace 80 percent of vent area with a
piece of flat sheet metal.
e. Furnace should cycle off within 2 minutes. If gas does not shut
off within 2 minutes, determine reason draft safeguard switch did
not function properly and correct condition.
f. Remove blockage from furnace vent elbow.
g. Switch will auto-reset when it cools.
h. Re-install vent connector.
NOTE: Should switch remain open longer than 3 minutes, furnace
control board will lockout the furnace for 3 hours. To reset furnace
control board, turn thermostat below room temperature or from HEAT to
OFF and turn 115-V power OFF, then back ON.
3. Check Pressure Switch
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
pressure switch is functioning properly, hot surface igniter
should NOT glow and control diagnostic light flashes a status
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
Table 9-Air Delivery-CFM (with
code (31.1). If hot surface igniter glows when inducer motor is
disconnected, shut down furnace immediately.
e. Determine reason pressure switch did not function properly and
correct condition.
f. Turn off 115-V power to furnace.
g. Reconnect inducer motor wires, replace outer 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
• 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 maintenance on this
equipment other than those procedures recommended in the User's
Manual.
!
ELECTRICAL SHOCK, FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal injury or death.
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.
servicing.
!
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.
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
36
WARNING
WARNING
Verify proper operation after
CAUTION