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Page 26

Troubleshooting Motor Windings

Ensure that motor windings are not damaged by perform­

ing the following tests:

NOTE

 - If your ohm meter is not an auto-ranging type, set it

to the highest ohm scale (100k ohms or greater) before

performing tests.

TABLE 14

Scale

Measurement Range

in words

ohms

2M

two megohm -- two
million ohms

0-2,000,000

200k

two hundred kilohm
-- two hundred thou­
sand ohms

0-200,000

20k

twenty kilohm --
twenty thousand
ohms

0-20,000

2k

two kilohm -- two
thousand ohms

0-2,000

200

two hundred ohm

0-200

FIGURE 10

TEST A

Measure the resistance between each of the three motor
leads (3-pin plug) and the unpainted part of the end shield.

If the winding resistance to ground is <100k
ohms, replace the motor and control module. If
the resistance to ground is >100k, the motor
windings are fine.  Proceed to Test B.

Test A

FIGURE 11

TEST B

Use an ohmmeter to measure the motor phase-to-phase
resistance by checking these combinations of the the 3-pin
motor plug. For the purpose of this test, start at either end of
the connector as lead 1.

 1 - The lead-to-lead resistance across any two leads

should be less than 20 ohms.

 2 - Each lead-to-lead resistance should be the same.

If the measured resistance is greater than 20 ohms, re­
place the motor and control module.

Test B

FIGURE 12

Summary of Contents for SL280UH060NV36A

Page 1: ...res outlined in this manual are presented as a recom mendation only and do not supersede or replace local or state codes In the absence of local or state codes the guidelines and procedures outlined i...

Page 2: ...according to FTC labeling regulations Isolated combustion system rating for non weatherized furnaces SPECIFICATIONS Gas Heating Performance Model No SL280UH080NV60C SL280UH100NV60C 1 AFUE 80 80 High F...

Page 3: ...Exchanger Combustion Air Inducer Gas Valve Intake Air Elbow Access Panel Inner Access Panel Intake Screen Blower Assem Power Choke 4 and 5 Ton Only Control Box includes integrated control interlock sw...

Page 4: ...ace entire control Can cause injury or death Unsafe operation will re sult if repair is attempted 4 Integrated Control A92 Units are equipped with the communicating enabled Sur eLight two stage variab...

Page 5: ...ermostat Move the DIP switch to ON for use with a single stage thermostat While in the single stage thermostat mode the burners will always fire on first stage heat The combustion air inducer will ope...

Page 6: ...STAGE T STAT R CLASS 2 VOLTAGE TO THERMOSTAT G MANUAL FAN FROM T STAT C THERMOSTAT SIGNAL GROUND CONNECTED TO TRANSFORMER GRD TR CHASIS GROUND GRD Y1 THERMOSTAT 1ST STAGE COOL SIGNAL Y2 THERMOSTAT 2N...

Page 7: ...2 100 50 OFF OPTION B OFF 82 100 OFF OPTION C OFF 100 100 OFF OPTION D OFF 100 OFF DEFAULT 10 10 HIGH SPEED MEDIUM HIGH SPEED MEDIUM LOW SPEED LOW SPEED 7 PROTECTIVE PLASTIC FILM ON DIP SWITCHES MAY B...

Page 8: ...e flame signal mode The integrated control will display the flame current on 7 segment LED in in micro amps uA Flame signal mode is exited after any of the following D Power is reset D Pressing and ho...

Page 9: ...clears 5 seconds after fault recovered E 111 Line voltage polarity reversed Reverse line power voltage wiring System resumes normal operation 5 seconds after fault recovered E 112 Ground not detected...

Page 10: ...re will be set as installed and that could be seen in About screen In normal operation after control recognizes sensors alarm will be sent if valid temperature reading is lost To get rid of set ting a...

Page 11: ...switch open during trial for ignition or run mode Refer to troubleshooting Check pressure inches w c of low pressure switch closing on heat call Measure operating pressure inches w c Inspect vent and...

Page 12: ...soft lockout Clears when calibra tion has finished successfully E 290 Ignitor circuit fault Failed ignitor or triggering circuitry Measure resistance of hot surface ignitor Replace if open or not wit...

Page 13: ...tegrated control with non communi cating outdoor unit Dual fuel module required for heat pump applica tion Configuration link R to O needs to be restored Re place link or hard wire Applicable in non c...

Page 14: ...econd 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...

Page 15: ...uns at 82 for approximately 7 1 2 minutes If demand has not been satisfied after 7 1 2 minutes motor runs at 100 until demand is satisfied S Once demand is met motor ramps down to stop OFF OFF 82 CFM...

Page 16: ...tage Heating Speed cfm Second Stage Heating Speed cfm 24 985 1100 18 950 1050 12 875 1000 6 850 935 Factory Default 800 890 6 750 840 12 700 790 18 680 740 COOLING 1 Cooling Speed DIP Switch Settings...

Page 17: ...tage Heating Speed cfm Second Stage Heating Speed cfm 24 1245 1385 18 1180 1320 12 1130 1245 6 1045 1185 Factory Default 1095 1120 6 1020 1050 12 825 975 18 840 865 COOLING 1 Cooling Speed DIP Switch...

Page 18: ...witch Settings First Stage Heating Speed cfm Second Stage Heating Speed cfm 24 1375 1530 18 1330 1450 12 1260 1390 6 1185 1315 Factory Default 1130 1235 6 1050 1165 12 980 1090 18 940 1020 COOLING 1 C...

Page 19: ...ressure Range HEATING 1 Heating Speed DIP Switch Settings First Stage Heating Speed cfm Second Stage Heating Speed cfm 24 1350 1485 18 1280 1420 12 1220 1345 6 1155 1270 Factory Default 1100 1200 6 10...

Page 20: ...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 1600 1785 18 1530 1685 12 1...

Page 21: ...t be cut if two stage cooling will be used If the Y1 to Y2 link is not cut the outdoor unit will operate in second stage cool ing only TABLE 12 OPERATING SEQUENCE SL280UHNV Non Communicating Thermosta...

Page 22: ...wing the room space to maintain a cooler room thermostat setpoint ROOM THERMOSTAT CALLS FOR FIRST AND SECOND STAGE COOLING BASIC MODE only active on a Y1 thermostat demand Normal Opera tion 1 On On On...

Page 23: ...S BEARING ROTOR The controller uses sensing devices to sense what position the rotor is in at any given time By sensing the position of the rotor and then switching the motor windings on and off in se...

Page 24: ...t before attempt ing to service motor DANGER Disconnect power from unit and wait at least five minutes to allow capacitors to discharge before at tempting to service motor Failure to wait may cause pe...

Page 25: ...48 5 Pin Line Voltage Connector J49 4 Pin Control Connector J48 5 Pin J49 4 Pin FIGURE 9 BLOWER B3 HARNESS CONNECTORS MOTOR with INTEGRATED CONTROLLER SHAFT P49 4 Pin P48 5 Pin P48 5 Pin P49 4 Pin J48...

Page 26: ...re the resistance between each of the three motor leads 3 pin plug and the unpainted part of the end shield If the winding resistance to ground is 100k ohms replace the motor and control module If the...

Page 27: ...regu lator adjustment screw is located on the valve LPG change over kits are available from Lennox Kits include burner orifices and a gas valve 4 Thermal Switch S47 The auto reset switch is located on...

Page 28: ...SL280UHNV HEATING COMPONENTS FIGURE 13 Air Gas Plenum Burner Gasket Orifice Housing Gas Valve Air Orifice Sensor Ignitor Gas Orifice Thermal Switch location Intake Air Screen Intake Air Elbow Coupling...

Page 29: ...is correct then then there is a problem with the wiring between the jack plug and control If the reading is not correct the issue is the ignitor Meter set to ohms Test 3 Insert meter probes into the t...

Page 30: ...the combustion air inducer is not operat ing or if the flue becomes obstructed On heat demand first or second stage the switch senses that the combustion air inducer is operating It closes a cir cuit...

Page 31: ...nit 1 Set thermostat to lowest setting 2 Turn off all electrical power to unit if service is to be per formed 3 Remove access panel 4 Move switch on valve to OFF Do not force 5 Replace access panel Fa...

Page 32: ...e to the manometer E Proper Gas Flow Approximate Furnace should operate at least 5 minutes before check ing gas flow Determine time in seconds for two revolu tions of gas through the meter Two revolut...

Page 33: ...power and gas supply to the fur nace 2 Remove the air hose fitting from the brass fitting on the air inlet screen 3 Use a 5 16 nut driver to loosen the clamps on the gray coupling 4 Remove the air inl...

Page 34: ...1 219 19X32 G Proper Combustion Furnace should operate a minimum 15 minutes with cor rect manifold pressure and gas flow rate before checking combustion Take combustion sample beyond the flue out let...

Page 35: ...eplace air orifice Check signal Pressure Signal pressure within range Replace gas valve Check the following 1 Vent air intake pipe restriction 2 Plugged air inlet screen 3 Signal hoses to gas valve fo...

Page 36: ...TEMPERATURE RISE Supply Duct Temperature ________ Return Duct Temperature _ _____ Temperature Rise ________ C External Static Pressure 1 Tap locations shown in figure 23 2 Punch a 1 4 diameter hole i...

Page 37: ...air inducer and clean if neces sary 8 Evaluate the heat exchanger integrity by inspecting the heat exchanger per the AHRI heat exchanger inspec tion procedure This procedure can be viewed at www ahrin...

Page 38: ...used by for eign matter Remove any blockage Figure 24 shows burner detail Replace gasket between burner plate and air fuel plenum then re install burner plate 10 To clean the combustion air inducer vi...

Page 39: ...IGURE 24 Gas Valve Air Intake Assembly Air Fuel Plenum Air Fuel Plenum Burner Heat Exchanger Re install screws per the numbered sequence shown Gasket Gasket Gasket replace FIGURE 25 Remove 5 screws if...

Page 40: ...at prove switch normally open contacts Once self check is complete and all safety switches are operational heat call can continue NOTE The ignition control thermostat selection DIP switch is factory s...

Page 41: ...operation The indoor blower motor is switched to the low fire heating speed 8 When the thermostat demand for low fire first stage heat is satisfied the gas valve is de energized and the field selected...

Page 42: ...r control and four wires between the outdoor unit and the fur nace air handler control When a thermostat cable with more than four wires is used the extra wires must be properly connected to avoid ele...

Page 43: ...RSBus Rf W Gh Gs Cf HVAC EQUIP DEHUMIDIFIER CONTROL HVAC EQUIPMENT DH STANDARD 1 OR 2 STAGE AC OR HP UNIT 24V IN JUMPER COMMUNICATING ENABLED FURNACE COMMUNICATING ENABLED FURNACE THERMOSTAT CONVENTIO...

Page 44: ...ON DO NOT CUT ANY ON BOARD LINKS S1 T STAT FURNACE TERM STRIP OUTDOOR UNIT 1 Heat 2 Cool NOTE Use DIP switch 2 to set second stage heat ON delay OFF 7 minutes ON 12 minutes ON CUT ON BOARD LINK W915...

Page 45: ...15 2 STAGE COMPR S1 T STAT FURNACE TERM STRIP OUTDOOR UNIT 2 Heat 2 Cool with t stat with humidity control OFF CUT ON BOARD LINK W915 2 STAGE COMPR CUT ON BOARD LINK W914 DEHUM OR HARMONY S1 T STAT FU...

Page 46: ...RD LINK W951 HEAT PUMP L7742U T STAT FURNACE TERM STRIP HEAT PUMP 67M41 Y H L Y2 D B L Y2 T T outdoor sensor Dual Fuel Two Stage Heat Pump ComfortSense thermostat w dual fuel capa bilities Capable of...

Page 47: ...NK W914 DEHUM OR HARMONY L7742U T STAT FURNACE TERM STRIP HEAT PUMP 67M41 Y H L Y2 D B L Y2 T T outdoor sensor Dual Fuel Two Stage Heat Pump ComfortSense thermostat w dual fuel capa bilities Capable o...

Page 48: ...od During that period press and hold push button for 5 seconds Integrated control will store code in memory and will automatically exit Program Unit Capacity Size Mode and reset If second period expir...

Page 49: ...DS H S I OFF NO INDUCER OFF AFTER POST PURGE HARD LOCKOUT ERROR CODE FLASHES YES YES YES 1 2 1 LOW PRESSURE SWITCH OPENS 1 2 HARD LOCKOUT REQUIRES THERMOSTAT RESET OR CYCLING OF POWER TO RESET THE LOC...

Page 50: ...ZED ONLY FOR 1ST REQUEST FOR 2ND STAGE HEAT YES CALL FOR HEAT SATISFIED INDUCER SWITCHED TO HIGH SPEED SINGLE STAGE THERMOSTAT 2 STAGE THERMOSTAT NO INDUCER SWITCHED TO LOW SPEED 5 MINUTE DELAY ERROR...

Page 51: ...L 2ND STAGE CALL FOR HEAT SATISFIED NO YES DE ENERGIZE 2ND STAGE GAS VALVE INDUCER SPEED SWITCHED TO LOW SPEED 1 2 3 1ST STAGE HEAT 1ST STAGE CALL FOR HEAT SATISFIED NO YES GAS VALVE DE ENERGIZED INDU...

Page 52: ...SPEED RAMPING PROFILES THE SPECIFIC PROFILE IS SELECTED USING THE 1 1 2 2 1 1 1 2 2 DE ENERGIZE 1ST STAGE COOLING CONTACTOR COMPRESSOR FAN 2ND STAGE COOLING REQUEST STILL ACTIVE COOLING REQUEST STILL...

Page 53: ...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 INDOOR BLOWER AT CONTINUOUS FAN MAINTAIN INDOOR BLOWER AT CONTINUOUS FAN DE ENERGIZ...

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