Lennox International Inc Troubleshooting Cooling Sequence of Operation, Call for Cooling

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Troubleshooting: Cooling Sequence of Operation (Continued)

CALL FOR COOLING

1

1ST STAGE COOLING REQUEST RECEIVED 1

WAIT FOR COMPRESSOR TIMED

OFF DELAY TO EXPIRE

ENERGIZE 1ST STAGE COOLING CONTACTOR (COMPRESSOR & FAN)

INDOOR BLOWER 2

SECOND ON DELAY

ENERGIZE INDOOR BLOWER	2
(LOW COOLING MODE)

MAINTAIN INDOOR

BLOWER

(LOW COOLING MODE)

YES

YES

	1				1ST STAGE
2ND STAGE					1ST STAGE
2ND STAGE			NO		COOLING REQUEST
COOLING

					STILL ACTIVE?
REQUEST?					STILL ACTIVE?

YES

YES

ENERGIZE 2ND STAGE		ENERGIZE INDOOR BLOWER
COOLING CONTACTOR		(HIGH COOLING MODE)	2
(COMPRESSOR & FAN)
(COMPRESSOR & FAN)

			NO
	2ND STAGE		MAINTAIN INDOOR BLOWER
	COOLING REQUEST	YES	MAINTAIN INDOOR BLOWER
	COOLING REQUEST	YES	(HIGH COOLING MODE)
	STILL ACTIVE?		(HIGH COOLING MODE)
	STILL ACTIVE?
	NO
	DE−ENERGIZE 2ND
	STAGE COOLING
	CONTACTOR
	(COMPRESSOR & FAN)
	1ST STAGE		ENERGIZE AND MAINTAIN
	COOLING REQUEST	YES	ENERGIZE AND MAINTAIN
	COOLING REQUEST	YES	INDOOR BLOWER AT
	STILL ACTIVE?		(LOW COOLING MODE)
			(LOW COOLING MODE)
	NO

DE−ENERGIZE 1ST

STAGE COOLING

CONTACTOR

(COMPRESSOR & FAN)

DE−ENERGIZE INDOOR

BLOWER 2

1CONTROL WILL NOT RESPOND TO A 2ND STAGE COOLING REQUEST UNLESS A 1ST STAGE COOLING REQUEST IS ACTIVE.

2INDOOR BLOWER LOW COOLING MODE AND HIGH COOLING MODE HAVE SPECIFIC ON, OFF AND SPEED RAMPING PROFILES. THE SPECIFIC PROFILE IS SELECTED USING THE

DIP SWITCHES ON THE CONROL.

1

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Contents Table of Contents Installation Instructions SL280UHVEither Side Unit Dimensions − inches mmReturn air from both sides Side Return Air OpeningSight Glass Access Panel Blower AssemblyParts Arrangement Shipping and Packing List Safety InformationSL280UHV Gas Furnace Evaporator Use of Furnace as Construction HeaterGeneral Air Handler UnitCombustion, Dilution & Ventilation Air Space ALL AIR from Inside Equipment in ConfinedEquipment Confined Space ALL AIR from Outside Equipment in Confined Space ALL AIR from OutsideEquipment in Confined Space Blower Motor Rigid LEG Setting EquipmentBottom Return AIR Base 20 X 25 XFurnace Front Indoor AIRTypical Horizontal Application Horizontal Application Installation Clearances Top LeftRight End BottomDuct System FiltersLeft Side Vent Discharge VentingUpflow Position Top Vent DischargeSide Vent Discharge Horizontal Left PositionHorizontal Right Position Vent Pipe Common Venting Using Metal−Lined Masonry ChimneyDisconnected Vent StickerThrough an unused masonry chimney flue is not considered Vent Connector102 127 −1/2 152 178 10−1/2 MIN MAX Feet FAN + FAN FAN + NAT 130 Carbon Monoxide Poisoning Hazard Every 8 to 10 feet 2.44 to 3.01 m with suitable hang Ers or straps. Install a drip leg in vertical pipe runs to− In some localities, codes may require the installation Gas PipingRight−Side Air Discharge Horizontal ApplicationLeft−Side Air Discharge BOX Interior MAKE−UP BOX InstallationElectrical Electrostatic Discharge ESDCommunicating Non−CommunicatingIcomfortt Integrated Control Outdoor Unit Icomfort Touch Applications NON−COMMUNICATING System WiringCommunicating System Wiring 120V ConnectionsDIP 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 + = Data High Connection − = Data LOW Connection Integrated ControlRS−BUS Link TB82, future use −10% approx OFF On−Board Links 880 1045985 940SL280UH090V36B Blower Performance less filter 1095 12801220 11551110 12951235 11701100 13601230 11651380 12901225 1160+18% 1605 SL280UH110V60C Blower Performance less filter +18% 1785 SL280UH135V60D Blower Performance less filter Operating Sequence Thermostat energizes Y2 CompressorHoneywell GAS Valve For Your Safety Read Before LightingUnit Start−Up White Rodgers GAS ValveDial Gas Pressure AdjustmentGAS Meter Clocking Chart Proper CombustionHigh Altitude Heating Sequence of Operation Other Unit AdjustmentsSEC Heating Operation with TWO−STAGE ThermostatHeating Operation with Single Stage Thermostat Electrical SHOCK, Fire Or Explosion Hazard Service17− Reinstall burner box, manifold assembly and burner box SL280UHV BURNER, Combustion AIR Inducer Assembly13− To clean the combustion air inducer visually inspect 11− Back wash using steam. Begin from the burner openingSL280UHV NOX Inserts Repair Parts List Planned ServiceIntegrated Control Diagnostic Codes Integrated Control Diagnostic ModesEquipment is unable to communicate. Indicates Normal operation 5 seconds after fault recoveredFurnace / air handler. Clears after fault recovered Power at the thermostat. Alert stops all servicesAte feature will be set as ’installed’ and that could Reconfigure the system. Replace control if heatingMissioning and Execute ’Set Factory Default mode’ Control will still operate on default parameter setTion after fault is cleared Low pressure switch failed openSumes normal operation after fault is cleared Fault is clearedTo flame failure Open or not within specifications −hour soft lockOut. Clears when flame has been proven stable Soft lockout or resetVice is removed, or after power reset Pair/add duct. Cleared after the current service deIs not running. Check power to outdoor unit. Clears Error after current is sensed in both RUNSor run cycle, or after power reset Finished Program Unit Capacity/Size ModeCall for FIRST−STAGE Heat Troubleshooting Heating Sequence of OperationCall for Heat Satisfied Call for SECOND−STAGE Heat2ND Stage Heat Call for Heat Satisfied FIRST−STAGE Heat SECOND−STAGE HeatCall for Cooling Troubleshooting Cooling Sequence of OperationCall for FAN Troubleshooting Continuous Fan Sequence of Operation