Download
Share
Print this page
Lennox ML193UHE Series Unit Information
  1. Manuals
  2. Brands
  3. Lennox Manuals
  4. Air Conditioner
  5. ML193UHE Series
  6. Unit information

Lennox ML193UHE Series Unit Information

Hide thumbs Also See for ML193UHE Series:

Advertisement

Quick Links

S e r v i c e L i t e r a t u r e
ML193UHE series units are high-efficiency gas furnac-
es manufactured with Lennox DuralokPlus
steel clamshell-type heat exchangers, with a stainless
steel condensing coil. ML193UHE units are available in
heating input capacities of 30,000 to 110,000 Btuh (8.8 to
32.2 kW) and cooling applications from 2 through 5 tons
(7.0 through 17.6 kW). Refer to Engineering Handbook for
proper sizing.
Units are factory equipped for use with natural gas. A kit
is available for conversion to LPG operation. All ML193U-
HE units are equipped with a hot surface ignition system.
The gas valve is redundant to assure safety shut-off as
required by C.S.A.
The heat exchanger, burners and manifold assembly can
be removed for inspection and service. The maintenance
section gives a detailed description on how this is done.
The ML193UHE can be "twinned" with a second unit. See
twinning kit 16W72 for information for two units to operate
as one, in a shared duct system controlled by a single
thermostat. All specifications are subject to change. Pro-
cedures outlined in this manual are presented as a rec-
ommendation only and do not supersede or replace local
or state codes.
WARNING
Electric shock hazard. Can cause injury
or death. Before attempting to perform
any service or maintenance, turn the
electrical power to unit OFF at disconnect
switch(es). Unit may have multiple power
supplies.

Table of Contents

Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
. . . . . . . . . . . . . . . . . . . . . . . . . . 4
. . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
II Placement and Installation . . . . . . . . . . . . . . . . . . . . 21
III-Start-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
V-Typical Operating Conditions
VI-Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
VII-Sequence of Operation and Flow Charts
UNIT INFORMATION
UNIT INFORMATION
ML193UHE SERIES UNITS
aluminized
™
. . . . . . . . . . . . . . . . . . . . . . 5
. . . . . . . . . . . . . . 41
. . . . . . . . . . . . . . . . . 45
. . . . . . 49
Corp 1905-L1
08/2022
Improper installation, adjustment, alteration, service
or maintenance can cause property damage,
personal injury or loss of life. Installation and service
must be performed by a licensed professional HVAC
instale (or equivalent), service agency or the gas
supplier.
As with any mechanical equipment, contact with
sharp sheet metal edges can result in personal
injury. Take care while handling this equipment and
wear gloves and protective clothing.
Page 1
ML193UHE
WARNING
CAUTION
©2016 Lennox Industries, Inc.

Advertisement

loading

Related Manuals for Lennox ML193UHE Series

Summary of Contents for Lennox ML193UHE Series

  • Page 1: Table Of Contents

    Corp 1905-L1 S e r v i c e L i t e r a t u r e 08/2022 ML193UHE SERIES UNITS ML193UHE series units are high-efficiency gas furnac- es manufactured with Lennox DuralokPlus aluminized ™ steel clamshell-type heat exchangers, with a stainless steel condensing coil.

  • Page 2: Specifications

    SP ECIF ICATIONS Model No. ML193UH030XE36B ML193UH045XE36B ML193UH070XE36B ML193UH090XE36C Heating AHRI Reference No. 20256877 20256878 20256879 20256880 Performance AFUE Input - Btuh 30,000 44,000 66,000 88,000 Output - Btuh 29,000 42,000 63,000 84,000 Temperature rise range - °F 25 - 55 30 - 60 40 - 70 50 - 80...

  • Page 3: Optional Accessories

    OPT IONAL AC C ESSORIES “B” Width Models “C” Width Models CABINET ACCESSORIES Horizontal Suspension Kit - Horizontal only 51W10 51W10 Return Air Base - Upflow only 50W98 50W99 High Performance Economizer (Commercial Only) 10U53 10U53 CONDENSATE DRAIN KITS Condensate Drain Heat Cable 6 ft.

  • Page 4: Blower Performance Data

    BLOWER DATA ML193UH030XE36B PERFORMANCE (Less Filter) Air Volume / Watts at Various Blower Speeds External High Medium-High Medium Medium-Low Static (Black) (Brown) (Blue) (Yellow) (Red) Pressure in. w.g. Watts Watts Watts Watts Watts 0.00 1435 1170 1000 0.10 1400 1130 0.20 1360 1085...
  • Page 5 BLOWER DATA ML193UH090XE48C PERFORMANCE (Less Filter) Air Volume / Watts at Various Blower Speeds External High Medium-High Medium Medium-Low Static (Black) (Brown) (Blue) (Yellow) (Red) Pressure in. w.g. Watts Watts Watts Watts Watts 0.00 1710 1500 1395 1315 1205 0.10 1675 1475 1365...
  • Page 6 PARTS IDENTIFICATION FLEXIBLE NO-HUB EXHAUST COLLAR BURNER BOX ASSEMBLY TOP CAP GAS VALVE DuralokPlus HEAT EXCHANGER ASSEMBLY COMBUSTION AIR INDUCER BURNER ACCESS PANEL BAG ASSEMBLIES (shipping location) PRIMARY LIMIT COLD END BLOWER ACCESS HEADER BOX PANEL BLOWER COMBUSTION ASSEMBLY AIR PRESSURE SWITCH CONTROL BOX former, circuit breaker and interlock switch)

  • Page 7: I-Unit Components

    I-UNIT COMPONENTS 3. Circuit Breaker (CB8) A 24V circuit breaker is also located in the control box. The ELECTROSTATIC DISCHARGE (ESD) switch provides overcurrent protection to the transform- Precautions and Procedures er (T1). The breaker is rated at 3A at 32V. If the current CAUTION exceeds this limit the breaker will trip and all unit opera- tion will shutdown.
  • Page 8 TABLE 3 1/4” Quick Connect Terminals 120HUM Humidifier 120VAC LINE 120VAC XFMR Transformer 120VAC CIRC Indoor blower 120VAC Indoor air quality accessory 120VAC NEUTRALS Common 120VAC HUM24 Humidifier 24VAC 3/16” Quick Connect Terminals COOL Cooling tap 24VAC HEAT Heating tap 24VAC Continuous blower 24 VAC PARK Park terminal for speed taps...
  • Page 9 Fan Time Control - Ignition Control 103217-03 IGNITION CONTROL 103217-03 Heating Fan On Time The fan on time of 30 seconds is not adjustable. Heating Fan Off Time Fan off time (time that the blower operates after the heat demand has been satisfied) can be adjusted by moving the jumper to a different setting.
  • Page 10 TABLE 5 Ignition Control 107163-01 RED LED Flash Code Diagnostic Codes / Status of Furnace No Power to Control or Board Fault Detected Board Fault Detected Fast Heartbeat Call for Heat / Burner Operation Slow Heartbeat Normal Operation – Idle, Continuous Fan, or Cool 1 Flash Reverse Line Voltage Polarity or Phasing of 120V power 2 Flashes...
  • Page 11 Burner Box Assembly Burner Assembly Rollout Switch(s) Flame Sensor Ignitor Gas Valve Burner Box Front FIGURE 6 B-Heating Components The combustion air inducer pulls fresh air through the burner box. This air is mixed with gas in the burners. The Combustion air inducer (B6), primary limit control (S10), gas / air mixture is then burned at the entrance of each ignitor, burners, flame rollout switch (S47), gas valve...
  • Page 12 5. Flame Sensor (FIGURE 6) Primary Limit Location and Heat Exchanger A flame sensor is located on the left side of the burner support. The sensor is mounted on the front burner box plate and the tip protrudes into the flame envelope of the leftmost burner.
  • Page 13 Measuring Flame Signal Flame Signal In Microamps Normal Drop Out 0.5 - 1.4 Flame Sensor Wire Remove sensor from integrated control and connect alligator clip (−) to flame sensor lead. Multi−Meter Intergrated Control Set Dial to DC MicroAmps Flame Sensor Terminal (−) T o Flame Terminal...
  • Page 14 Test 1 Check ignitor circuit for correct resistance. Remove 4-pin plug from control. Check ohms reading across terminals 2 and 4. Reading should be between 39 and 70 ohms. If value is correct, this is the only test needed. If the reading on the meter is not correct, (0 or infinity) then a second test is needed.
  • Page 15 -110 1.406” TABLE 7 8. Combustion Air Pressure Switch (FIGURE 11) Altitude Ft ML193UHE series units are equipped with a differential 0-4500 4501-7500 7501-10000 Unit pressure switch located on the cold end header box. The switch monitors across the combustion air inducer orifice Set Point “w.c.
  • Page 16 Measuring Pressure Differential Black Tubing (positive +) Red and Black Tubing or Red Tubing (negative -) To Cold End Header Box To Cold End Header Box Field Provided Tubing To Pressure Switch “+” High “-” 1 - Remove thermostat demand and allow unit to cycle off.
  • Page 17 TABLE 8 Problem Corrective Action Check that the pressure switch is open without the com- Pressure switch stuck closed bustion air inducer operating. Replace if defective. Pressure switch does not close due to obstruction in vent Check for restricted vent. Remove all blockage. Check for pipe.
  • Page 18 C- Blower Compartment BLOWER WHEEL REPLACEMENT IMPORTANT Center Blower Wheel in Blower Housing Each blower is statically and dynamically balanced as an assembly before installation in the unit. ML193UHE units are equipped with a constant torque ECM motor. It has a DC motor coupled to an electronic control module both contained in the same motor housing.
  • Page 19 Multi−Meter (set to VAC) Multi−Meter (set to VAC) Test 1 Test 3 (if necesssary) Turn on power to unit. Check for 120 volts across terminals Check for 120 volts across terminals “CIRC” and “Neutrals” “L” and “N” on input plug P48. If voltage is present continue on the integrated control.
  • Page 20 Replacing the Motor Module Motor Test 1 - Disconnect electrical power to unit. 2 - Remove unit access panel. 3 - Unplug the two harnesses from the motor control module. See FIGURE 17. 4 - Remove the two hex head bolts securing the motor control module to the motor.
  • Page 21 II-PLACEMENT AND INSTALLATION IMPORTANT Pipe & Fittings Specifications Exhaust and intake connections are made of PVC. Use PVC primer and solvent cement when using All pipe, fittings, primer and solvent cement must conform PVC vent pipe. When using ABS vent pipe, use with American National Standard Institute and the Ameri- transitional solvent cement to make connections to can Society for Testing and Materials (ANSI/ASTM) stan-...
  • Page 22 TABLE 11 OUTDOOR TERMINATION USAGE* STANDARD CONCENTRIC Wall Kit 1-1.2 inch 2 inch 3 inch Flush Mount Kit 2 inch 3 inch Vent Pipe 71M80 69M29 Input Size Field 60L46 (US) 51W11 22G44 Dia. in. (US) (US) 44J40 (US) Fabricated 44W93 (US) (US)
  • Page 23 Vent Piping Guidelines 2 - When furnace is installed in a residence where unit NOTE - Lennox has approved the use of DuraVent is shut down for an extended period of time, such ® Centrotherm manufactured vent pipe and terminations as a vacation home, make provisions for draining as an option to PVC.
  • Page 24 In some applications which permit the use of several dif- Which needs ferent sizes of vent pipe, a combination vent pipe may be most elbows? used. Contact Lennox’ Application Department for assis- Intake or tance in sizing vent pipe in these applications. exhaust? NOTE - The exhaust collar on all models is sized to ac- commodate 2”...
  • Page 25 TABLE 13 Maximum Allowable Intake or Exhaust Vent Length in Feet NOTE - Size intake and exhaust pipe length separately. Values in table are for Intake OR Exhaust, not combined total. Both Intake and Exhaust must be same pipe size NOTE - Additional vent pipe and elbows used to terminate the vent pipe outside the structure must be included in the total vent length calculation.
  • Page 26 TYPICAL EXHAUST AND INTAKE PIPE CONNECTIONS IN UPFLOW DIRECT OR NON-DIRECT VENT APPLICATIONS 2” EXHAUST EXHAUST INTAKE INTAKE 2” 2” 2” 2” 2” 3” 3” 030/045/070 Only 1−1/2” TRANSITION Exhaust 2” 6” Min Exhaust DO NOT transition from larger to smaller DO NOT transition pipe in horizontal runs from smaller to larger...
  • Page 27 Intake Piping TYPICAL AIR INTAKE PIPE CONNECTIONS The ML193UHE furnace may be installed in either direct HORIZONTAL NON−DIRECT VENT APPLICATIONS vent or non-direct vent applications. In non-direct vent ap- (Horizontal Right−Hand Air Discharge Application Shown) plications, when intake air will be drawn into the furnace from the surrounding space, the indoor air quality must be considered and guidelines listed in Combustion, Dilution and Ventilation Air section must be followed.
  • Page 28 General Guidelines for Vent Terminations CAUTION In Non-Direct Vent applications, combustion air is taken If this unit is being installed in an application with from indoors and the flue gases are discharged to the out- combustion air coming in from a space serviced by an doors.
  • Page 29 TABLE 15 Maximum Allowable Exhaust Vent Pipe Length (in ft.) Without Insulation In Unconditioned Space For Winter Design Temperatures Single - Stage High Efficiency Furnace Winter Design Unit Input Size Vent Pipe Temperatures1 °F Diameter (°C) 1-1/2” 32 to 21 2 in (0 to -6) 2-1/2 in...
  • Page 30 ‡ Permitted only if veranda, porch, deck or balcony is fully open NOTE - This figure is intended to illustrate clearance on a minimum of two sides beneath the floor. Lennox recommends requirement and does not serve as a substitute for avoiding this location if possible.
  • Page 31 ‡ Permitted only if veranda, porch, deck or balcony is fully open on a minimum of locally adopted installation codes. two sides beneath the floor. Lennox recommends avoiding this location if possible. FIGURE 33 Page 31...
  • Page 32 Details of Intake and Exhaust Piping Terminations for TABLE 16 Direct Vent Installations Exhaust Pipe Termination Size Reduction NOTE - In Direct Vent installations, combustion air is taken ML193UHE Model Termination Pipe Size from outdoors and flue gases are discharged to outdoors. *030, *045, *070 1-1/2”...
  • Page 33 7 - If intake and exhaust piping must be run up a side wall to position above snow accumulation or other obstructions, piping must be supported. At 12” EXHAUST least one bracket must be used within 6” from the (305mm) VENT 5-1/2”...
  • Page 34 FIELD FABRICATED WALL TERMINATION NOTE − FIELD−PROVIDED REDUCER MAY BE 2” (51mm) 3” (76mm) REQUIRED TO ADAPT Vent Pipe Vent Pipe LARGER VENT PIPE SIZE TO TERMINATION A− Minimum clearance above grade or average 12” (305 mm) 12” (305 mm) snow accumulation B−...
  • Page 35 4 - Distance between exhaust pipe terminations on FIGURE 44 multiple furnaces must meet local codes. Crawl Space and Extended Horizontal Venting Lennox provides kit 51W18 (USA) kit 15Z70 (Canada) to 12” (305mm) install 2” or 3” PVC exhaust piping through the floor joists ABOVE AVE.
  • Page 36 If this is not pos- sible, a heat cable kit may be used on the condensate trap and line. Heating cable kit is available from Lennox in various lengths; 6 ft. (1.8m) - kit no. 26K68 and 24 ft.
  • Page 37 CONDENSATE TRAP LOCATIONS Condensate Trap With Optional Overflow Switch (Unit shown in upflow position with remote trap) From Evaporator Coil HorizontalFurnace4” Min. to 5” Max.above FieldProvidedVent condensatedrain connection) Min. 1” Above Condensate Drain Connection 1” Min. 2” Max. FurnaceCondensate DrainConnection *5’...
  • Page 38 Furnace with Evaporator Coil Using a Separate Drain (Unit shown in horizontal left-hand discharge position) Field Provided Vent Evaporator (4” min. to 5” max. above Coil condensate connection) 4”min 5”max 5’ max. PVC Pipe Only Condensate Drain Connection (Trap at coil is optional) Drain Pan Piping from furnace and evaporator coil must slope down a minimum 1/4”...
  • Page 39 TRAP / DRAIN ASSEMBLY USING 1/2” PVC OR 3/4” PVC Optional Condensate Drain Connection Adapter 3/4 inch slip X 3/4 inch mpt (not furnished) 90° Street Elbow 3/4 inch PVC (not furnished) Adapter 3/4 inch slip X 3/4 inch mpt (not furnished) Condensate Drain Connection In Unit 1 (25 mm) Min.

  • Page 40: Iii-Start-Up

    III-START-UP 2 - Set the thermostat to the lowest setting. 3 - Turn off all electrical power to the unit. A-Preliminary and Seasonal Checks 4 - This furnace is equipped with an ignition device 1 - Inspect electrical wiring, both field and factory which automatically lights the burners.

  • Page 41: Iv-Heating System Service Checks

    Use of a All units are C.S.A. design certified without modifications. specialty Gas Leak Detector is strongly recommended. It is available through Lennox under part number 31B2001. Refer to the ML193UHE Operation and Installation In- See Corp. 8411-L10, for further details.
  • Page 42 Manifold Pressure Measurement Follow the steps below and use FIGURE 56 as a reference. Gas manifold Kit 10L34 provides additional components if needed. 1 - Connect the test gauge positive side “+“ to manifold pressure tap on gas valve. 2 - Tee into the gas valve regulator vent hose and connect to test gauge negative “-”. 3 - Start unit and let run for 5 minutes to allow for steady state conditions.
  • Page 43 E-Proper Combustion F-High Altitude Furnace should operate minimum 15 minutes with correct NOTE - In Canada, certification for installations at eleva- manifold pressure and gas flow rate before checking com- tions over 4500 feet (1372 m) is the jurisdiction of local bustion.
  • Page 44 G- Proper Ground and Voltage 2 - In addition, measure the AC voltage from Line Hot to Line Neutral (spade terminals) on the integrated WARNING control. See figure 57. This voltage should be in the range of 97 to 132 Vac Electric Shock Hazard.
  • Page 45 V-TYPICAL OPERATING CHARACTERISTICS C-External Static Pressure 1 - Tap locations shown in FIGURE 59. A-Blower Operation and Adjustment1 2 - Punch a 1/4” diameter hole in supply and return NOTE- The following is a generalized procedure and does air plenums. Insert manometer hose flush with not apply to all thermostat controls.

  • Page 46: Vi-Maintenance

    Check the condensate hose screens for blockage and specifications provided by the filter manufacturer against clean if necessary. the data given in the appropriate Lennox Product 1 - Turn off power to the unit. Specifications bulletin. Additional information is provided in Service and Application Note ACC002 2 - Remove hoses from cold end header box.
  • Page 47 17 - Mark and disconnect any remaining wiring to Condensate Hose Screens heating compartment components. Disengage strain relief bushing and pull wiring and bushing through the hole in the blower deck. 18 - Remove the primary limit from the vestibule panel. 19 - Remove top cap screws to allow top cap to be tilted upward to allow clearance for removing heat Hose...
  • Page 48 40 - Secure burner assembly to vestibule panel using 7 - Disconnect and label ground wire from burner/ four existing screws. Burners are self aligning to manifold assembly. center of clam shells. 8 - Remove four screws that secures burner/manifold 41 - Reconnect gas supply line to gas valve.
  • Page 49 VII-WIRING DIAGRAM AND SEQUENCE OF OPERATION FIGURE 61 When there is a call for heat, W1 of the thermostat energizes W of the furnace control with 24VAC. S10 primary limit switch and S47 rollout switch are closed. Call for heat can continue. The integrated control (A92) energizes combustion air inducer B6.
  • Page 50 VIII-Troubleshooting: Heating Sequence of Operation HEATING SEQUENCE OF OPERATION ABNORMAL HEATING MODE NORMAL HEATING MODE POWER ON GAS VALVE OFF. COMBUSTION AIR INDUCER OFF. INDOOR BLOWER DELAY OFF. CONTROL SELF-CHECK OKAY? LED SLOW FLASH (RESET CONTROL BY TURNING MAIN POWER OFF.) LED FLASHES CODE 1 - POLARITY REVERSED.
  • Page 51 Heating Sequence of Operation Continued HEATING SEQUENCE CONTINUED 15 SECOND COMBUSTION AIR INDUCER PREPURGE INITIATED BY CLOSED PRESSURE SWITCH. LED FLASHES CODE 13 - LOW LINE VOLTAGE. ONCE VOLTAGE IS ABOVE IS VOLTAGE ABOVE 70 VOLTS? IGNITOR WARM UP -- 20 SECONDS. 75 VOLTS, HEATING SEQUENCE RESTARTS.
  • Page 52 Cooling Sequence of Operation COOLING SEQUENCE OF OPERATION POWER ON IGNITION CONTROL MAIN POWER ON. GAS VALVE OFF. COMBUSTION AIR INDUCER OFF. INDOOR BLOWER OFF WITH NORMAL DELAY. CONTROL SELF DIAGNOSTIC CHECK. SIGNAL CIRCUIT BOARD FAILURE AT LED. IS CONTROL OPERATING NORMALLY? INTERRUPT MAIN POWER TO RESET CONTROL.
  • Page 53 Continuous Fan / Accessories Sequence of Operation CONTINUOUS FAN SEQUENCE OF OPERATION LED: SLOW FLASH RATE REMAINS UNCHANGED THROUGHOUT SEQUENCE. MANUAL FAN SELECTION MADE AT THERMOSTAT. CONTROL (G) ENERGIZES SYSTEM FAN AT FAN SPEED. EAC TERMINAL IS ENERGIZED. THERMOSTAT CALLS FOR HEAT (W). SYSTEM FAN CONTINUES FAN SPEED WITHOUT THERMOSTAT CALLS FOR COOLING.

This manual is also suitable for:

Ml193uh030xe36bMl193uh045xe36bMl193uh070xe36bMl193uh090xe36cMl193uh090xe48cMl193uh110xe48c ... Show all