Lennox International Inc SL280UH090V36B, SL280UH090V48B, SL280UH070V36A 2ND Stage Heat

Page 70

Troubleshooting: Heating Sequence of Operation (Continued)

CALL FOR HEAT SATISFIED

FIRST−STAGE HEAT SECOND−STAGE HEAT

RUN MODE:

1ST OR 2ND STAGE CALL FOR HEAT.

ALL INPUTS MONITORED (LIMIT, PRESSURE, CALL FOR HEAT/COOL, FLAME LEVEL)

2ND STAGE HEAT

2ND STAGE

CALL FOR HEAT

SATISFIED?

YES

DE−ENERGIZE 2ND STAGE

GAS VALVE

INDUCER SPEED SWITCHED

TO LOW SPEED

INDOOR BLOWER SWITCHED

TO LOW HEAT SPEED

1ST STAGE HEAT

1ST STAGE

CALL FOR HEAT

SATISFIED?

YES

GAS VALVE

DE−ENERGIZED

INDUCER OFF AFTER

5 SECOND POST PURGE

INDOOR BLOWER OFF

AFTER FIELD SELECTABLE

OFF DELAY

Page 70

Image 70

Contents Installation Instructions SL280UHV Table of ContentsSide Return Air Opening Unit Dimensions − inches mmReturn air from both sides Either SideParts Arrangement Access Panel Blower AssemblySight Glass SL280UHV Gas Furnace Safety InformationShipping and Packing List Air Handler Unit Use of Furnace as Construction HeaterGeneral EvaporatorCombustion, Dilution & Ventilation Air Equipment in Confined Space ALL AIR from InsideEquipment in Confined Space Equipment in Confined Space ALL AIR from OutsideEquipment Confined Space ALL AIR from Outside Bottom Setting EquipmentBlower Motor Rigid LEG Indoor AIR 20 X 25 XFurnace Front Return AIR BaseEnd Bottom Horizontal Application Installation Clearances Top LeftRight Typical Horizontal ApplicationFilters Duct SystemTop Vent Discharge VentingUpflow Position Left Side Vent DischargeHorizontal Right Position Horizontal Left PositionSide Vent Discharge Sticker Common Venting Using Metal−Lined Masonry ChimneyDisconnected Vent 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 Gas Piping Ers or straps. Install a drip leg in vertical pipe runs to− In some localities, codes may require the installation Every 8 to 10 feet 2.44 to 3.01 m with suitable hangLeft−Side Air Discharge Horizontal ApplicationRight−Side Air Discharge Electrostatic Discharge ESD Interior MAKE−UP BOX InstallationElectrical BOXNon−Communicating CommunicatingIcomfortt Integrated Control Outdoor Unit Icomfort Touch 120V Connections NON−COMMUNICATING System WiringCommunicating System Wiring 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 RS−BUS Link TB82, future use Integrated Control+ = Data High Connection − = Data LOW Connection −10% approx OFF On−Board Links 940 1045985 880SL280UH090V36B Blower Performance less filter 1155 12801220 10951170 12951235 11101165 13601230 11001160 12901225 1380+18% 1605 SL280UH110V60C Blower Performance less filter +18% 1785 SL280UH135V60D Blower Performance less filter Operating Sequence Compressor Thermostat energizes Y2White Rodgers GAS Valve For Your Safety Read Before LightingUnit Start−Up Honeywell GAS ValveProper Combustion Gas Pressure AdjustmentGAS Meter Clocking Chart DialHigh Altitude Other Unit Adjustments Heating Sequence of OperationHeating Operation with Single Stage Thermostat Heating Operation with TWO−STAGE ThermostatSEC Service Electrical SHOCK, Fire Or Explosion Hazard11− Back wash using steam. Begin from the burner opening SL280UHV BURNER, Combustion AIR Inducer Assembly13− To clean the combustion air inducer visually inspect 17− Reinstall burner box, manifold assembly and burner boxSL280UHV NOX Inserts Planned Service Repair Parts ListIntegrated Control Diagnostic Modes Integrated Control Diagnostic CodesPower at the thermostat. Alert stops all services Normal operation 5 seconds after fault recoveredFurnace / air handler. Clears after fault recovered Equipment is unable to communicate. IndicatesControl will still operate on default parameter set Reconfigure the system. Replace control if heatingMissioning and Execute ’Set Factory Default mode’ Ate feature will be set as ’installed’ and that couldFault is cleared Low pressure switch failed openSumes normal operation after fault is cleared Tion after fault is clearedSoft lockout or reset Open or not within specifications −hour soft lockOut. Clears when flame has been proven stable To flame failureError after current is sensed in both RUN Pair/add duct. Cleared after the current service deIs not running. Check power to outdoor unit. Clears 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