Lennox International Inc SL280UH090V48B, SL280UH070V36A, SL280UH090V36B 10% approx

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Integrated Control DIP Switch Settings − Conventional Thermostat (non−communi- cating)

SL280UHV units are equipped with a two−stage, variable speed integrated control. This control manages ignition timing, heating mode fan off delays and indoor blower speeds based on selections made using the control dip switches and jumpers. The control includes an internal watchguard feature which automatically resets the ignition control when it has been locked out. After one hour of con- tinuous thermostat demand for heat, the watchguard will break and remake thermostat demand to the furnace and automatically reset the control to relight the furnace.

Note: All icomfortt settings are set at the icomfort Touch® thermostat. See icomfortt installation instruction. In icom- fortt communication system all DIP switch and clippable link settings are ignored. For conventional thermostats pro- ceed with DIP switch and clippable link settings as outlined in the following.

Heating Operation DIP Switch Settings

Switch 1 −− Thermostat Selection −− This unit may be used with either a single−stage or two−stage thermostat. The thermostat selection is made using a DIP switch which must be properly positioned for the particular application. The DIP switch is factory−positioned for use with a two− stage thermostat. If a single−stage thermostat is to be used, the DIP switch must be repositioned.

Select " for two−stage heating operation con- trolled by a two−stage heating thermostat (factory set- ting);

b − Select " for two−stage heating operation con- trolled by a single−stage heating thermostat. This set- ting provides a timed delay before second−stage heat is initiated.

Switch 2 −− Second Stage Delay (Used with Single− Stage Thermostat Only) −− This switch is used to deter- mine the second stage on delay when a single−stage ther- mostat is being used. The switch is factory−set in the OFF position, which provides a 7−minute delay before second− stage heat is initiated. If the switch is toggled to the ON position, it will provide a 12−minute delay before second− stage heat is initiated. This switch is only activated when the thermostat selector jumper is positioned for SINGLE− stage thermostat use.

Switches 3 and 4 −− Blower−Off Delay −− The blower−on delay of 30 seconds is not adjustable. The blower−off delay (time that the blower operates after the heating demand has been satisfied) can be adjusted by moving switches 3 and 4 on the integrated control. The unit is shipped from the factory with a blower−off delay of 90 seconds. The blower off delay affects comfort and is adjustable to satisfy individ- ual applications. Adjust the blower off delay to achieve a supply air temperature between 90° and 110°F at the exact moment that the blower is de−energized. Longer off delay

settings provide lower supply air temperatures; shorter set- tings provide higher supply air temperatures.Table 12 pro- vides the blower off timings that will result from different switch settings.

TABLE 12

Blower Off Delay Switch Settings

Blower Off Delay

Switch 3

Switch 4

(Seconds)

 

 

60

On

Off

90 (Factory)

Off

Off

120

Off

On

180

On

On

Indoor Blower Operation DIP Switch Settings Switches 5 and 6 −− Cooling Mode Blower Speed −− The unit is shipped from the factory with the dip switches posi- tioned for high speed (4) indoor blower motor operation during the cooling mode. Table 13 provides the cooling mode blower speeds that will result from different switch settings. Switches 5 and 6 set the blower cfm for second− stage cool. The integrated control automatically ramps down to 70% of the second−stage cfm for first−stage cfm. Refer to tables for corresponding cfm values.

TABLE 13

Cooling Mode Blower Speeds

Speed

Switch 5

Switch 6

Low

On

On

Medium Low

Off

On

Medium High

On

Off

High (Factory)

Off

Off

Switches 7 and 8 −− Cooling Blower Speed Adjustment

−−The unit is shipped from the factory with the dip switches positioned for NORMAL (no) adjustment. The dip switches may be positioned to adjust the blower speed by +10% or −10% to better suit the application. Table 14 below provides blower speed adjustments that will result from different switch settings. Refer to tables for corresponding cfm val- ues.

TABLE 14

Cooling Blower Speed Adjustment

Adjustment

Switch 7

Switch 8

+10% (approx.)

On

Off

Factory Default

Off

Off

−10% (approx.)

Off

On

Switches 9 and 10 −− Cooling Mode Blower Speed Ramping −− Blower speed ramping may be used to en- hance dehumidification performance. The switches are factory set at option A which has the greatest effect on de− humidification performance. Table 15 provides the cooling mode blower speed ramping options that will result from different switch settings. The cooling mode blower speed ramping options are detailed on the next page.

NOTE − The off portion of the selected ramp profile also ap- plies during heat pump operation in dual fuel applications.

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Contents Installation Instructions SL280UHV Table of ContentsUnit Dimensions − inches mm Return air from both sidesSide Return Air Opening Either SideAccess Panel Blower Assembly Parts ArrangementSight Glass Safety Information SL280UHV Gas FurnaceShipping and Packing List Use of Furnace as Construction Heater GeneralAir Handler Unit EvaporatorCombustion, Dilution & Ventilation Air Equipment in Confined Space ALL AIR from InsideEquipment in Confined Space ALL AIR from Outside Equipment in Confined SpaceEquipment Confined Space ALL AIR from Outside Setting Equipment BottomBlower Motor Rigid LEG 20 X 25 X Furnace FrontIndoor AIR Return AIR BaseHorizontal Application Installation Clearances Top Left RightEnd Bottom Typical Horizontal ApplicationFilters Duct SystemVenting Upflow PositionTop Vent Discharge Left Side Vent DischargeHorizontal Left Position Horizontal Right PositionSide Vent Discharge Common Venting Using Metal−Lined Masonry Chimney Disconnected VentSticker Vent PipeVent Connector Through an unused masonry chimney flue is not considered102 127 −1/2 152 178 10−1/2 MIN MAX Feet FAN + FAN FAN + NAT 130 Carbon Monoxide Poisoning Hazard Ers or straps. Install a drip leg in vertical pipe runs to − In some localities, codes may require the installationGas Piping Every 8 to 10 feet 2.44 to 3.01 m with suitable hangHorizontal Application Left−Side Air DischargeRight−Side Air Discharge Interior MAKE−UP BOX Installation ElectricalElectrostatic Discharge ESD BOXNon−Communicating CommunicatingIcomfortt Integrated Control Outdoor Unit Icomfort Touch NON−COMMUNICATING System Wiring Communicating System Wiring120V Connections ApplicationsDIP Switch Settings and On−Board Links See figure OFF Single Stage Thermostat w Dual fuel capa Bilities SL280UHV Schematic Wiring Diagram Typical SL280UHV Field Wiring Diagram Integrated Control RS−BUS Link TB82, future use+ = Data High Connection − = Data LOW Connection −10% approx OFF On−Board Links 1045 985940 880SL280UH090V36B Blower Performance less filter 1280 12201155 10951295 12351170 11101360 12301165 11001290 12251160 1380+18% 1605 SL280UH110V60C Blower Performance less filter +18% 1785 SL280UH135V60D Blower Performance less filter Operating Sequence Compressor Thermostat energizes Y2For Your Safety Read Before Lighting Unit Start−UpWhite Rodgers GAS Valve Honeywell GAS ValveGas Pressure Adjustment GAS Meter Clocking ChartProper Combustion DialHigh Altitude Other Unit Adjustments Heating Sequence of OperationHeating Operation with TWO−STAGE Thermostat Heating Operation with Single Stage ThermostatSEC Service Electrical SHOCK, Fire Or Explosion HazardSL280UHV BURNER, Combustion AIR Inducer Assembly 13− To clean the combustion air inducer visually inspect11− Back wash using steam. Begin from the burner opening 17− Reinstall burner box, manifold assembly and burner boxSL280UHV NOX Inserts Planned Service Repair Parts ListIntegrated Control Diagnostic Modes Integrated Control Diagnostic CodesNormal operation 5 seconds after fault recovered Furnace / air handler. Clears after fault recoveredPower at the thermostat. Alert stops all services Equipment is unable to communicate. IndicatesReconfigure the system. Replace control if heating Missioning and Execute ’Set Factory Default mode’Control will still operate on default parameter set Ate feature will be set as ’installed’ and that couldLow pressure switch failed open Sumes normal operation after fault is clearedFault is cleared Tion after fault is clearedOpen or not within specifications −hour soft lock Out. Clears when flame has been proven stableSoft lockout or reset To flame failurePair/add duct. Cleared after the current service de Is not running. Check power to outdoor unit. ClearsError after current is sensed in both RUN Vice is removed, or after power resetSor run cycle, or after power reset Program Unit Capacity/Size Mode FinishedTroubleshooting Heating Sequence of Operation Call for FIRST−STAGE HeatCall for SECOND−STAGE Heat Call for Heat SatisfiedCall for Heat Satisfied FIRST−STAGE Heat SECOND−STAGE Heat 2ND Stage HeatTroubleshooting Cooling Sequence of Operation Call for CoolingTroubleshooting Continuous Fan Sequence of Operation Call for FAN
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