Lennox ML180UHE Series Manual
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- Installation instructions manual (44 pages) ,
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- User's information manual (7 pages)
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S e r v i c e L i t e r a t u r e
ML180UHE(X) series units are mid-efficiency gas furnac-
es used for upflow or horizontal applications only, man-
ufactured with Lennox Duralok heat exchangers formed
of aluminized steel. ML180UHE(X) units are available in
heating capacities of 44,000 to 132,000 Btuh and cooling
applications 2 to 5 tons. Refer to Engineering Handbook
for proper sizing.
Units are factory equipped for use with natural gas. Kits
are available for conversion to LP/Propane operation.
ML180UHE(X) model units are equipped with a hot sur-
face ignition system. The ML180UHE(X) unit meets the
California Nitrogen Oxides (NOx) Standards and Califor-
nia Seasonal Efficiency requirements.
All units use a redundant gas valve to assure safety shut-
off as required by C.S.A. All specifications in this manual
are subject to change. Procedures outlined in this manual
are presented as a recommendation only and do not su-
persede or replace local or state codes. In the absence
of local or state codes, the guidelines and procedures
outlined in this manual (except where noted) are recom-
mended only and do not constitute code.
WARNING
Improper
installation,
service or maintenance can cause property damage,
personal injury or loss of life. Installation and service
must be performed by a licensed professional HVAC
installer (or equivalent), service agency or the gas
supplier.
TABLE OF CONTENTS
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 2
Blower Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 4
Parts Identification . . . . . . . . . . . . . . . . . . . . . . . . . Page 6
I Unit Components . . . . . . . . . . . . . . . . . . . . . . . . Page 7
II Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 21
III Start Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 21
V Typical Operating Characteristics . . . . . . . . . Page 26
VI Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . Page 26
UNIT INFORMATION
UNIT INFORMATION
Corp 1120-L4
Revised 10-2017
ML180UHE(X) SERIES UNITS
adjustment,
alteration,
Electric Shock Hazard. Can cause injury
or death. Unit must be properly grounded
in accordance with national and local
codes.
Line voltage is present at all components
when unit is not in operation on units
with single-pole contactors. Disconnect
all remote electric power supplies before
opening access panel. Unit may have
multiple power supplies.
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
ML180UHE(X)
WARNING
CAUTION
©2016 Lennox Industries, Inc.
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Table of Contents
Related Manuals for Lennox ML180UHE Series
Summary of Contents for Lennox ML180UHE Series
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Page 1: Table Of Contents
ML180UHE(X) series units are mid-efficiency gas furnac- es used for upflow or horizontal applications only, man- ufactured with Lennox Duralok heat exchangers formed of aluminized steel. ML180UHE(X) units are available in heating capacities of 44,000 to 132,000 Btuh and cooling applications 2 to 5 tons. -
Page 2: Specifications
SPECIFI CAT IONS Model No. ML180UH045E36A ML180UH070E36A ML180UH070E36B ML180UH090E48B Heating Model No. - Low Nox ML180UH045XE36A ML180UH070XE36A ML180UH070XE36B ML180UH090XE48B Performance AFUE Input - Btuh 44,000 66,000 66,000 88,000 Output - Btuh 36,000 53,000 53,000 72,000 Temperature rise range - °F 15 - 45 40 - 70 40 - 70... - Page 3 O PTI ONAL ACCESS ORIES - ORDER SE PA RAT E LY “A” Width “B” Width “C” Width “D” Width Models Models Models Models CABINET ACCESSORIES Horizontal Suspension Kit - Horizontal only 51W10 51W10 51W10 51W10 Return Air Base - Upflow only 65W75 50W98 50W99...
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Page 4: Blower Data
B L OWER DATA ML180UH045E36A 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 1380 1155 0.10 1345 1120 0.20 1320... - Page 5 ML180UH090E60C PERFORMANCE (Less Filter) Air Volume / Watts at Different Blower Speeds Bottom Return Air, Side Return Air from Both Sides or Return Single Side Return Air − Air volumes in bold (over 1800 cfm) Air from Bottom and One Side. require Optional Return Air Base and field fabricated transition to External accommodate 20 x 25 x 1 in.
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Page 6: Parts Identification
PARTS ARRANGEMENT Make-Up Box Heat Exchanger Combustion Air Inducer Combustion Air Inducer Pressure Switch Burner Box (includes sensor, ignitor and rollout switches) Gas Valve Primary Limit Control Box (under (includes integrated control, combustion interlock switch and transformer) air inducer) Upper Access Panel Blower Assembly Blower Access Panel Power Choke... -
Page 7: I Unit Components
I-UNIT COMPONENTS 4. Integrated Control (A92) ML180UHE(X) unit components are shown in figure 1.The WARNING gas valve, combustion air inducer and burners can be ac- cessed by removing the upper access panel. Electrical Shock hazard. components are in the control box (figure 2) found in the Disconnect power before servicing. - Page 8 TABLE 3 TABLE 1 1/4” Quick Connect Terminals 4-Pin Terminal Designation 120HUM Humidifier 120VAC PIN # FUNCTION LINE 120VAC Combustion Air Inducer Line XFMR Transformer 120VAC Ignitor Line CIRC Indoor blower 120VAC Combustion Air Inducer Neutral Indoor air quality accessory 120VAC Ignitor Neutral NEUTRALS Common 120VAC...
- Page 9 TABLE 4 (-02 inegrated Control) RED LED Diagnostic Codes / Status of Furnace Flash Code No power to control or board fault detected Heartbeat Normal Operation - Idle, Continuous Fan, Cool Reverse Line Voltage Polarity Improper Earth Ground Burner failed to light, or lost flame during heat demand Low Flame Signal - check flame sensor Watchguard - burner failed to light, exceeded maximum number of retries or recycles.
- Page 10 TABLE 5 (-03 Integrated Control) RED LED Diagnostic Codes / Status of Furnace Flash Code No power to control or board fault detected Heartbeat Normal Operation - Idle, Continuous Fan, Cool Continuous Rapid Flash Call For Heat / Burner Operation Reverse Line Voltage Polarity Improper Earth Ground Burner failed to light, or lost flame during heat demand...
- Page 11 ELECTRONIC IGNITION 5 SEC Trial for Pre -Purge Ignitor Warm-up Blower “On”* Post Ignition Delay Purge DEMAND IGNITOR GAS VALVE INDOOR BLOWER *Blower on time will be 30 seconds after flame is sensed. Blower off time will depend on “OFF TIME” Setting. FIGURE 4 Fan Time Control Cooling Fan On Time...
- Page 12 The switch may have flame signal is sensed. a different setpoint for each unit model number. If limit switch must be replaced, refer to Lennox ProductZone re- A microamp DC meter is needed to check the flame signal pair parts list.
- Page 13 Flame (microamp) signal is an electrical current which 4 - Connect (-) lead to flame sensor wire. passes from the integrated control to the sensor during 5 - Connect (+) lead to Terminal FS on integrated control. unit operation. Current passes from the sensor through 6 - Turn supply voltage on and close thermostat contacts the flame to ground to complete a safety circuit.
- Page 14 Inlet and outlet pressure taps are located on the valve. A Model C.A.I. Orifice Size regulator adjustment screw is located on the valve. LPG 045E36A 1.063” changeover kits are available from Lennox. Kits include 070E36B 1.316” burner orifices and a gas valve regulator spring. 090E48B, 090E60C 1.531”...
- Page 15 IGNITOR CHECKS Test 1 Check ignitor circuit for correct resistance. Remove 4-pin plug from control. Check ohms reading across terminals 2 and 4. The 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 16 11. Combustion Air Inducer Pressure Switch (S18) TABLE 8 ML180UHE(X) series units are equipped with a combus- inches wc Unit tion air pressure switch located on the combustion air in- Make Break + 0.05 ducer orifice bracket. The switch is connected to the com- 045E36A-1, -2, -54 -0.75 -0.65...
- Page 17 Multiple Venting Remove the four mounting screws, rotate the assembly (assembly consists of orifice plate, proving switch, gasket The ML180UHE(X) furnace can vent in multiple positions. and combustion air inducer), then reinstall the mounting See figure 11. The make up box may be removed and the screws.
- Page 18 12. Blower Motor 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. ML180UHE 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 15. Unplug the Two Harness Connection TWO HARNESS CONNECTIONS MOTOR MOTOR CONTROL MODULE...
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Page 21: Installation
II- PLACEMENT AND INSTALLATION Turning Off Gas to Unit 1 - Set the thermostat to the lowest setting. Make sure unit is installed in accordance with installation instructions and applicable codes. 2 - Turn off all electrical power to the unit if service is to be performed. - Page 22 3 - While waiting for the unit to stabilize, observe the specialty Gas Leak Detector is strongly recommended. It flame. Flame should be stable and should not lift is available through Lennox under part number 31B2001. from burner. Natural gas should burn blue. See Corp. 8411-L10, for further details.
- Page 23 TABLE 12 Manifold Pressure Settings at all Altitudes Line Pressure in. wg. Model 7501 - 10,000 0 - 2000 ft. 2001 -4500 ft . 4501 - 7500 ft. Input Size 13.0 LP/Propane 10.0 10.0 10.0 10.0 11.0 13.0 13.0 LP/Propane 10.0 10.0 10.0...
- Page 24 H- Proper Ground and Voltage TABLE 14 A poorly grounded furnace can contribute to poor flame Measurement VAC Furnace Status sense signal. Use the following procedure to check for Expected Maximum ground and voltage to the integrated control. Power on Furnace Idle 1 - Measure the AC voltage between Line Neutral (spade terminals) and “C”...
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Page 25: Typical Operating Characteristics
V-TYPICAL OPERATING CHARACTERISTICS C-External Static Pressure 1 - Tap locations shown in figure 24 . A-Blower Operation and Adjustment 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 26: Maintenance
At the beginning of each heating season, and to comply 6 - Check the cleanliness of blower assembly and with the Lennox Limited Warranty, your system should be clean the housing, blower wheel and blower motor checked by a licensed professional technician (or equiva- if necessary . - Page 27 3 - Clock gas meter to ensure that the unit is operating 3 - Label the wires from gas valve, rollout switches, at the specified firing rate. Check the supply primary limit switch and make-up box then pressure and the manifold pressure. On two-stage disconnect them.
- Page 28 7 - NOX units only - Remove screw securing NOX NOx INSERTS insert. Remove NOX insert. See figure 26. 8 - Remove screws from both sides, top and bottom of vestibule panel. 9 - Remove heat exchanger. It may be necessary to spread cabinet side to allow more room.
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Page 29: Wiring And Sequence Of Operation
VII- Wiring and Sequence of Operation Schematic Wiring Diagram and Sequence of Operation Line voltage is applied to L1 and N. the T1 low voltage transformer is energized, and line voltage is applied to B3 indoor blower. S47 rollout switch(es) must be closed in order for 24V from transformer to be output on integrated control ”R” to power thermostat. When there is a call for heat, W1 of the thermostat energizes W of the furnace control with 24VAC. - Page 30 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. IS POLARITY CORRECT? LED FLASHES CODE 2 - IMPROPER GROUND.
- Page 31 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 32 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. LED FLASHES CODE 2 IMPROPER GROUND IS THERE A PROPER GROUND? CONTROL WILL CONTINUE TO CALL FOR COOLING...
- Page 33 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.