Lennox SL280DFV - Manuals

Page 5 chilled air from entering the furnace (see figure 1). If thedamper is manually operated, it must be equipped to pre-vent operation of either the heating or the cooling unit, un-less it is in the full HEAT or COOL setting. FIGURE 1 AIR HANDLER GAS UNIT Dampers (open during cooling operation on...

Page 6 D The gas cock must be T handle" type. D When a furnace is installed in an attic, the passage-way to and service area surrounding the equipmentshall be floored. WARNING Product contains fiberglass wool. Disturbing the insulation in this product duringinstallation, maintenance, or repair w...

Page 7 Confined Space A confined space is an area with a volume less than 50 cu-bic feet (1.42 m 3 ) per 1,000 Btu (.29 kW) per hour of the combined input rating of all appliances installed in thatspace. This definition includes furnace closets or smallequipment rooms. When the furnace is installed ...

Page 8 EQUIPMENT IN CONFINED SPACE ALL AIR FROM OUTSIDE (Inlet Air from Crawlspace and Outlet Air to Ventilated Attic) NOTE−The inlet and outlet air openings shall each have a free area of at least one square inch (645 mm 2 ) per 4,000 Btu (1.17 kW) per hour of the total input rating of all equipmen...

Page 9 Downflow Installation Downflow unit installs in three ways: on non−combustibleflooring, on combustible flooring using a downflow com-bustible flooring base, or on a reverse−flow cooling cabinet.Do not drag the unit across the floor. Installation on Non−Combustible Flooring (Figure 6) 1 − Cut ...

Page 10 SL280DFV UNIT COOLING COIL PLENUM FIGURE 8 PROPERLY SIZED FLOOR OPENING Return Air Opening −− Downflow Units The following steps should be taken when installing ple-num: 1 − Bottom edge of plenum should be flanged with a hemmed edge (See figure 9). SECURE FROM OUTSIDE CABINET HEMMED EDGE PLE...

Page 11 FIGURE 12 Front Back Horizontal Downflow ApplicationAllow for clearances to combustible materials as indi-cated on the unit nameplate. Minimum clearances forcloset or alcove installations are shown in figure 13. Downflow Application Installation Clearances Top Bottom Left Side Right Side Typ...

Page 12 Duct System Use industry-approved standards (such as those pub-lished by Air Conditioning Contractors of America or Ameri-can Society of Heating, Refrigerating and Air ConditioningEngineers) to size and install the supply and return air ductsystem. This will result in a quiet and low-static ...

Page 13 FIGURE 15 Common Venting Using Tile−Lined Interior Masonry Chimney and Combined Vent Connector MINIMUM LENGTH = AS SHORT AS PRACTICAL. FOR MAXIMUM LENGTH SEE NOTE TO LEFT INTERIOR TILE−LINEDMASONRY CHIMNEY NOTE − the chimney must be properlysized per provided venting tables orlined with list...

Page 14 Never connect a Category I appliance to a chimney that isservicing a solid−fuel appliance. If a fireplace chimney flueis used to vent this appliance, the fireplace opening mustbe permanently sealed. A type B or listed chimney lining system that passesthrough an unused masonry chimney flue is...

Page 19 Removal of the Furnace from Common Vent In the event that an existing furnace is removed from aventing system commonly run with separate gas ap-pliances, the venting system is likely to be too large toproperly vent the remaining attached appliances. Conduct the following test while each appl...

Page 20 TABLE 11 Gas Pipe Capacity − ft 3 /hr (m 3 /hr) Nominal Iron Pipe Size inches (mm) Internal Diameter inches (mm) Length of Pipe − feet (m) 10 (3.048) 20 (6.096) 30 (9.144) 40 (12.192) 50 (15.240) 60 (18.288) 70 (21.336) 80 (24.384) 90 (27.432) 100 (30.480) 1/2 (12.7) .622 (17.799) 175 (4.96)...

Page 21 Leak Check After gas piping is completed, carefully check all pipingconnections (factory− and field−installed) for gas leaks. Usea leak detecting solution or other preferred means. NOTE − If emergency shutoff is necessary, shut off the mainmanual gas valve and disconnect the main power to th...

Page 22 2 − Holes are on both sides of the furnace cabinet to facili- tate wiring. 3 − Install a separate (properly sized) disconnect switch near the furnace so that power can be turned off forservicing. 4 − Before connecting the thermostat or the power wiring, check to make sure the wires will be l...

Page 25 TABLE 13 SL280 Field Wiring Applications With Conventional Thermostat Thermostat DIP Switch Settings and On−Board Links (See figure 25) Wiring Connections DIP Switch 1 Thermostat Heating Stages On Board Links Must Be Cut To Select System Options 1 Heat / 1 Cool NOTE − Use DIPswitch 2 to sets...

Page 26 TABLE 13 SL280 Field Wiring Applications With Conventional Thermostat (Continued) Thermostat DIP Switch Settings and On−Board Links (See figure 25) Wiring Connections DIP Switch 1 Thermostat Heating Stages On Board Links Must Be Cut To Select System Options 2 Heat / 2 Cool OFF CUT ON−BOARD L...

Page 29 SL280DFV Schematic Wiring Diagram FIGURE 23

Page 30 TYPICAL SL280DFV FIELD WIRING DIAGRAM FIGURE 24 FIELD INSTALLED CLASS II 24V FIELD INSTALLED LINE VOLTAGE

Page 31 Integrated Control FIGURE 25 THERMOSTAT CONNECTIONS (TB1) 1/4" QUICK CONNECT TERMINALS RS−BUS LINK (TB82, future use) I+ = DATA HIGH CONNECTIONI − = DATA LOW CONNECTION RS−BUS OUTDOOR (TB83) R = 24VACI + = DATA HIGH CONNECTIONI − = DATA LOW CONNECTIONC = 24VAXC COMMON RS−BUS INDOOR (TB84...

Page 34 On−Board Links Note: In icomfort t systems with a conventional outdoor unit (non−communicating), the on−board clippable linksmust be set to properly configure the system WARNING Carefully review all configuration information pro-vided. Failure to properly set DIP switches, jumpersand on−boar...

Page 35 BLOWER DATA SL280DF070V36A BLOWER PERFORMANCE (less filter) 0 through 0.8 in. w.g. (Heating) and 0 through 1.0 in. w.g. (Cooling) External Static Pressure Range HEATING 1 Heating Speed DIP Switch Settings First Stage Heating Speed - cfm Second Stage Heating Speed - cfm +24% 1065 1170 +18% 10...

Page 37 TABLE 20 SL280DFV, Non−Communicating Thermostat with Humidity Control Feature and Single−Speed Outdoor Unit OPERATING SEQUENCE SYSTEM DEMAND SYSTEM RESPONSE System Condition Step Thermostat Demand Relative Humidity Compressor Blower CFM (COOL) Comments Y1 O G W 1 Status D NO CALL FOR DEHUMID...

Page 39 Unit Start−Up FOR YOUR SAFETY READ BEFORE LIGHTING WARNING Do not use this furnace if any part has been underwa-ter. Immediately call a licensed professional servicetechnician (or equivalent) to inspect the furnace andto replace any part of the control system and any gascontrol which has bee...

Page 40 12− If the appliance will not operate, follow the instructions Turning Off Gas to Unit" and call your service techni-cian or gas supplier. Turning Off Gas to Unit 1 − Set the thermostat to the lowest setting. 2 − Turn off all electrical power to the unit if service is to be performed. 3 ...

Page 41 High Altitude The manifold pressure, gas orifice and pressure switchmay require adjustment or replacement to ensure properoperation at higher altitudes. Tables 24 through 27 showsmanifold pressure, pressures switch and gas conversionkits at all altitudes. IMPORTANT For safety, shut unit off ...

Page 43 Applications Using A Single−Stage Thermostat See figure 29 for ignition control sequence B − Heating Sequence −− Control Thermostat SelectionDIP Switch 1 ON in Single−Stage" Position NOTE − In these applications, two−stage heat will be initi-ated by the integrated control if heating dema...

Page 44 Service WARNING ELECTRICAL SHOCK, FIRE, OR EXPLOSION HAZARD. Failure to follow safety warnings exactly could resultin dangerous operation, serious injury, death orproperty damage.Improper servicing could result in dangerous opera-tion, serious injury, death, or property damage.Before servici...

Page 46 12− To clean the combustion air inducer visually inspect and using a wire brush clean where necessary. Use com-pressed air to clean off debris and any rust. 13− Reinstall heat exchanger in vestibule. (Replace the five screws in the cabinet from step 10 if removed). 14− Reinstall collector bo...

Page 48 Integrated Control Diagnostic Modes Display Action (when button released) No change (idle)* Remain in idle mode Solid E" Enter diagnostic recall mode Solid D" Discharge Air Installed Solid F" Enter flame signal mode Solid P" (variable speed only) Program unit capacity/size (U...

Page 49 Integrated Control Diagnostic Codes (continued) Code Diagnostic Codes/Status of Equipment Action Required to Clear and Recover E 105 Device communication problem − No other devices on RS BUS (Commu-nicationsystem). Equipment is unable to communicate. Indicatesnumerous message errors. In most...

Page 54 Integrated Control Diagnostic Codes (continued) E 406 LSOM − Compressor open start circuit. Required amount of current is not passing throughStart current transformer. Clears the error after cur-rent is sensed in START sensor, or after power re-set. E 407 LSOM − Compressor open run circuit. ...

Page 55 Program Unit Capacity/Size Mode Power−Up − Number displayed represents by integrated control unit size code (furnace model and capacity). If three horizontal bars are displayed followed by continuous E203, furnacecontrol does not recognize unit size code. Configure per the following: Furnace...

Page 56 Troubleshooting: Heating Sequence of Operation HIGH LIMIT SWITCH CLOSED? LOW PRESSURE SWITCH OPEN? INDUCER ON PRE − PURGE (15 SECONDS) 1ST STAGE GAS VALVE ENERGIZED FLAME SENSED WITHIN 4 SECONDS? (LOW HEAT SPEED) HEAT FAN OFF DELAY (LOW HEAT SPEED) AFTER HEAT FAN OFF DELAY (LOW HEAT SPEED) Y...

Page 60 Troubleshooting: Continuous Fan Sequence of Operation CALL FOR FAN CALL FOR FAN REMOVED? YES NO NO REQUEST FOR HEAT RECEIVED? REQUEST FOR COOLING RECEIVED? GO TO CALL FOR 1ST STAGE HEAT YES GO TO CALL FOR COOLING 1 1 1 4 YES NO CALL FOR FAN INDOOR BLOWER ON CONTINUOUS FAN SPEED MAINTAIN INDO...