Carrier 100 Series Service And Maintenance Procedures Manual

Contents

Carrier 100 Series Service And Maintenance Procedures Manual Manual pdf 4 page image

10. If a greasy residue is present on blower wheel, remove wheelfrom the blower housing and wash it with an appropriatedegreaser. To remove wheel:a. Mark blower wheel location on shaft before disassembly toensure proper reassembly.b. Loosen setscrew holding blower wheel on motor shaft.NOTE: Mark blower mounting arms, motor, and blower housingso motor and each arm is positioned at the same location duringreassembly.c. Mark blower wheel orientation and cutoff plate location toensure proper reassembly.d. Remove screws securing cutoff plate and remove cutoffplate from housing.e. Disconnect capacitor and ground wire attached to blowerhousing before removing motor.f. Remove bolts holding motor and motor mounts to blowerhousing and slide motor and mounts out of housing. Motormount belly band need not be removed unless motor is to bereplaced.g. Remove blower wheel from housing.The blower wheel should not be dropped or bent as balancewill be affected.11. Reassemble motor and blower by reversing items 9a through9g. Be sure to reattach ground wire.12. Reinstall blower assembly in furnace.13. Reinstall control and transformer support assembly in furnace.14. Reconnect blower leads to furnace control.Refer to furnace wiring diagram, and connect thermostat leadsif previously disconnected. (See Fig. 7.)NOTE: Refer to Table 2 for motor speed lead relocation if leadswere not identified before disconnection.Heating air speed selection MUST be adjusted to provideproper air temperature rise as specified on the rating plate.Failure to adjust the heating speed may shorten heat ex-changer life. Recommended operation is at the midpoint ofrise range or above.15. Downflow or horizontal furnaces with vent pipe throughfurnace only: Reinstall internal vent pipe by reversing items 3aand 3b.16. Reinstall vent connector to furnace vent elbow. Securelyfasten vent connector to vent elbow with 2 field-supplied,corrosion-resistant, sheet metal screws located 180° apart.17. Turn on electrical supply. Manually close blower access doorswitch. Use a piece of tape to hold switch closed. Check forproper rotation and speed changes between heating andcooling by jumpering R-to-W/W1 R-to-W/W1-and-W2, andthen R-to-Y on furnace control thermostat terminals.Blower access door switch opens 115-v power to furnacecontrol. No component operation can occur. Caution must betaken when manually closing this switch for service purposes.Failure to follow this warning could result in electrical shock,personal injury, or death.NOTE: If thermostat terminals are jumpered at the time bloweraccess door switch is closed, blower will run for 90 sec beforebeginning a heating or cooling cycle.18. If furnace is operating properly, REMOVE TAPE TO RE-LEASE BLOWER ACCESS DOOR SWITCH, and thenreplace blower access door.Step 3—Cleaning Heat ExchangerThe following steps should be performed by a qualified servicetechnician:NOTE: If the heat exchangers get a heavy accumulation of sootand carbon, they should be replaced rather than trying to cleanthem thoroughly. A build-up of soot and carbon indicates that aproblem exists which needs to be corrected, such as improperadjustment of manifold pressure, insufficient or poor qualitycombustion air, incorrect size or damaged manifold orifice(s),improper gas, or a restricted heat exchanger. Action must be takento correct the problem.If it becomes necessary to clean the heat exchangers because ofdust or corrosion, proceed as follows:1. Turn OFF gas and electrical power to furnace.2. Remove outer access door.3. Disconnect vent connector from furnace vent elbow.4. For downflow or horizontal furnace having an internal ventpipe, disconnect internal vent pipe within the casing.5. Disconnect wires to the following components. Mark wires toaid in reconnection of:a. Draft safeguard switch.b. Inducer motor.c. Pressure switches.d. Limit overtemperature switch.e. Gas valve.f. Hot surface igniter.g. Flame-sensing electrodeh. Flame rollout switches.6. Remove screws that fasten the inducer assembly with backingplate to the cell panel. Be careful not to damage backing plate.Inducer assembly and elbow need not be removed frombacking plate.7. Remove burner, gas manifold and support assembly and NOxdevices if present. Individual burners need not be removedfrom support assembly.NOTE: Be very careful when removing burner assembly to avoidbreaking igniter. See Fig. 4 for correct igniter location.8. Using field-provided small wire brush, steel spring cable,reversible electric drill, and vacuum cleaner, clean cells asfollows:a. Assemble wire brush and steel spring cable.TABLE 2—SPEED SELECTORCOLOR SPEEDFACTORY-ATTACHEDTOWhite Common BLWBlack High COOLYellow (When Present) Medium High SPAREOrange† Medium SPAREBlue Medium Low HI HEATRed Low LO HEAT† Available on 5-speed blowers only.4