Page 1: Table Of Contents
2022 INSTALLATION INSTRUCTIONS WARNING To prevent serious injury or death: LHT/LDT078H Lock-out/tag-out before performing maintenance. (6.5 Ton) If system power is required (e.g., smoke detector mainte LHT/LDT092H nance), disable power to blower, remove fan belt where (7.5 Ton) applicable, and ensure all controllers and thermostats are LHT/LDT102H set to the “OFF”...
Page 2: Dimensions
CAUTION As with any mechanical equipment, contact with sharp sheet metal edges can result in personal in jury. Take care while handling this equipment and wear gloves and protective clothing. LHT/LDT078, 092, 102H DIMENSIONS - GAS HEAT SECTION SHOWN 6-1/8 5-5/8 BOTTOM SUPPLY (156)
Page 3 LHT/LDT122, 150H DIMENSIONS - GAS HEAT SECTION SHOWN 6−1/8 5−5/8 BOTTOM SUPPLY (156) (143) AIR OPENING 6−1/8 10−3/4 (156) (610) (711) (273) (508) (686) 60−1/8 (1527) BASE BOTTOM BOTTOM RETURN AIR OPENING POWER ENTRY 5−1/2 (140) Dia. 6−5/8 7 (178) (168) BOTTOM 7 (178)
Page 4: Parts Arrangements
LHT078, 092, 102, 120, 150 PARTS ARRANGEMENT OUTDOOR FANS BLOWER INDOOR (3 ON 122 & 150) (DIRECT DRIVE) COIL FILTERS (FOUR - 20 X 25 X 2”) ECONOMIZER (OPTIONAL) WIFI ANTENNA UNIT CONTROLLER WIRELESS BOARD OUTDOOR COIL ELECTRIC HEAT CONDENSATE COMPRESSORS (OPTIONAL) REVERSING...
Page 5: Shipping And Packing List
Shipping and Packing List UNIT CLEARANCES Package 1 of 1 contains: 1- Assembled unit Optional Outdoor Check unit for shipping damage. Receiving party should Air Hood contact last carrier immediately if shipping damage is found. General These instructions are intended as a general guide and do not supersede local codes in any way.
Page 6: Unit Support
S The unit operating conditions (including airflow, The LHT/LDT unit is ETL/CSA certified for outdoor installations only at the clearances to combustible cooling operation, ignition, input rate, temperature materials listed on unit nameplate and in figure 1. rise and venting) must be verified according to these installation instructions.
Page 7: Duct Connection
4- Duct must be attached to the roof mounting frame 3- All panels must be in place for rigging. and not to the unit. Supply and return plenums must 4- Place field‐provided H‐style pick in place just above be installed before setting the unit. top edge of unit.
Page 8 Rear Drain Connection CONDENSATE SIDE DRAIN CONNECTION 1- Open blower and heat access doors. See figure 5. CAULK AROUND CONDENSATE COUPLING BLOWER ACCESS DOOR FILTER ACCESS DOOR NOTE - Allow clearance to open doors when installing condensate piping. UNIT Minimum Pitch 1”...
Page 9: Gas Piping
6- Make sure the cap over the unit bottom drain hole is 7- From the inside of the pan, use a Vari-Bit ® bit to secure. enlarge the hole to 7/8”. Do not damage coupling threads. 7- Rotate the drain pan until the downward slope is 8- Remove the cap over the unit bottom drain hole.
Page 10: Pressure Test Gas Piping
OUTSIDE OF UNIT GAS PIPE CONNECTION BOTTOM GAS ENTRY THROUGH THE UNIT ALL ELBOWS ARE 3/4” MULLION BETWEEN HEAT AND COMPRES SOR SECTIONS 5” NIPPLE GROMMET TO GAS VALVE 4” NIPPLE 10” NIPPLE GROUND 7-1/2” NIPPLE JOINT UNION GROMMET 4” NIPPLE TO GAS TO GAS VALVE...
Page 11: High Altitude Derate
Download Mobile Service App PRESSURE TEST GAS LINE A-Mobile Device Requirements S Android hardware requires 2GB RAM and a 2Ghz core processor. Tablets are supported. MANUAL MAIN S Minimum Android 6.0 (Marshmallow) or higher. SHUT-OFF VALVE Recommend Android 10 and Apple products require iOS version 11 or higher.
Page 12: Electrical Connections - Power Supply
Electrical Connections - Power Supply Electrical Connections - Control Wiring NOTE ‐ Optional wireless sensors are available for use with this unit. Refer to the instructions provided with Route field wiring in conduit between bottom power entry each sensor. disconnect. See figure 14. This does not supersede local codes or authorities having jurisdiction.
Page 13 3- Connect thermostat wiring to Unit Controller on the Zone Sensor Mode lower side of the controls hat section. The Unit Controller will operate heating and cooling 4- Wire as shown in figure 15 for electro-mechanical based on the Unit Controller internal setpoints and the electronic thermostats.
Page 14: Blower Operation And Adjustments
Initiate blower only (G) demand at thermostat according Blower Operation to instructions provided with thermostat. Unit will cycle on Units are equipped with variable speed, direct drive thermostat demand. The following steps apply to blowers. The supply CFM can be adjusted by changing applications using typical...
Page 15 LOCATION OF STATIC PRESSURE READINGS INSTALLATIONS WITH DUCTWORK INSTALLATIONS WITH CEILING DIFFUSERS ROOFTOP UNIT ROOFTOP UNIT RETURN AIR READING LOCATION RETURN AIR READING RE RE SUPPLY SUPPLY LOCATION TURN TURN FIRST BRANCH OFF OF MAIN RUN MAIN DUCT RUN SUPPLY AIR SUPPLY AIR READING READING...
Page 16: Direct Drive Start-Up
Blower calibration is required only on units that are newly Direct Drive Blower Start-Up installed or if there is a change in the duct work or air filters after installation. Use the mobile service app to navigate The supply CFM can be adjusted by changing the to the SETUP>TEST &...
Page 17 BLOWER DATA BLOWER TABLE INCLUDES RESISTANCE FOR BASE UNIT ONLY (NO HEAT SECTION) WITH DRY INDOOR COIL AND AIR FILTERS IN PLACE. FOR ALL UNITS ADD: 1 − Wet indoor coil air resistance of selected unit. 2 − Any factory installed options air resistance (heat section, Economizer, etc.) 3 −...
Page 18 BL OWER D ATA FACTORY INSTALLED OPTIONS/FIELD INSTALLED ACCESSORY AIR RESISTANCE - in. w.g. Wet Indoor Coil Gas Heat Exchanger Filters Return Electric Econo Volume Heat 120, 122, Standard Medium High mizer Adaptor 092, 102 MERV 8 MERV 13 MERV 16 (LHT) Heat Heat...
Page 19: Cooling Start-Up
Cooling Start-Up REFRIGERANT STAGES - THREE FANS LHT/LDT122, 150H: IMPORTANT-The crankcase heater must be energized Two-Stage Thermostat/Control: for 24 hours before attempting to start compressor. Set Y1 Demand = Outdoor Fans 1, 2, & 3 MEDIUM Speed thermostat so there is no demand to prevent Y2 Demand = Outdoor Fans 1, 2 &...
Page 20: Lht/Ldt078H
C-Refrigerant Charge and Check - Fin/Tube TABLE 5 581119-01 LHT/LDT092 WARNING-Do not exceed nameplate charge under any condition. Circuit 1 Circuit 2 Outdoor This unit is factory charged and should require no further Coil Dis Dis Suction Suction Entering charge charge adjustment.
Page 21: Prognostic & Diagnostic Sensors
Charge Verification - Subcooling Method - AHRI Testing (4413 kPa + 70 kPa) and automatically resets at 475 psig + 20 psig (3275kPa + 138 kPa). Attach gauge manifolds to discharge and suction lines. With the economizer disabled, operate the unit in 2- Low Pressure Switch (S87, S88) cooling mode at high speed using the following mobile The compressor circuit is protected by a loss of...
Page 22 LHT/LDT078, 092, 102, 122, 150 INDOOR COIL RT46, RT47 22J06 BLUE RT47 22J06 YELLOW RT46 DETAILS NOT TO SCALE FIGURE 21 Page 22...
Page 23 LHT/LDT078, 092, 102, 122, 150 OUTDOOR COIL RT48, RT49 22J08 BLUE RT49 22J08 YELLOW RT48 DETAILS NOT TO SCALE FIGURE 22 Page 23...
Page 24: Warning
This unit is equipped with an automatic spark ignition Heating Start-Up (LDT) system. There is no pilot. In case of a safety shutdown, move thermostat switch to OFF and return the thermostat FOR YOUR SAFETY READ BEFORE LIGHTING switch to HEAT to reset ignition control. WARNING A-Placing Unit In Operation Electric shock hazard.
Page 25: Gas Supplier
4- This appliance is equipped with an ignition device 13- If the appliance does not light the first time (gas line which automatically lights the burner. Do not try to not fully purged), it will attempt up to two more light the burner by hand.
Page 26: Heating Operation And Adjustments
C-Limit Controls Heating Operation and Adjustments Limit controls are factory-set and are not adjustable. The (Gas Units) primary limit is located on the blower deck to the right of A-Heating Sequence of Operation the blower housing. 1- On a heating demand the combustion air inducer D-Heating Adjustment starts immediately.
Page 27: Cooling Operation
C-Three-Stage Thermostat Cooling Operation 1-Economizer With Outdoor Air Suitable This is a summary of cooling operation. Refer to the Y1 Demand - sequence of operation provided in the Engineering Compressors Off Handbook or Service Manual for more detail. Blower Cooling Medium Dampers Modulate A-Two-Stage Thermostat Y2 Demand -...
Page 28: Service
C-Burners (Gas Units) Service Periodically examine burner flames proper The unit should be inspected once a year by a qualified appearance during the heating season. Before each service technician. heating season examine the burners for any deposits or blockage which may have occurred. CAUTION Clean burners as follows: Label all wires prior to disconnection when servic...
Page 29 5- Check the alignment of the ignitor and the sensor as Under normal operating conditions, the combustion air shown in figure 28 and table 11. inducer wheel should be checked and cleaned prior to the heating season. However, it should be examined TABLE 11 periodically during the heating season to establish an Length - in.
Page 30 HEAT EXCHANGER ASSEMBLY INSERT LOCATION STANDARD HEAT (130,000BTUH) HEAT EXCHANGER TUBE Note - No inserts on medium and high heat. COMBUSTION AIR INDUCER INSERTS (2) VENT CONNECTOR GAS VALVE BURNER FIGURE 29 FIGURE 30 E-Flue Passageway and Flue Box (Gas Units) G-Indoor Coil Inspect and clean coil at beginning of each cooling season.
Page 31 BIPOLAR IONIZER IONIZER ASSEMBLY FIGURE 31 UVC ASSEMBLY UVC LAMP UVC ASSEMBLY ASSEMBLY SECURED DOOR WITH 3 SCREWS SWITCH FIGURE 32 Page 31...
Page 32 L-UVC Light INSTALL LAMP IN HOLDER CLIPS When field-installed, use only UVC Light Kit assembly 106882-01 (21A93) with this appliance. Sub-Assembly Factory-Installed UVC Light When the UVC light is factory installed, the lamp is shipped in a foam sleeve. The lamp is attached to the BANDS (see Note below) UVC light assembly on the blower deck.
Page 33 Unintended use of the unit or damage to the unit Proper Clean-up Technique in Case of Lamp Breakage housing may result in the escape of dangerous UVC radiation. UVC radiation may, even in small doses, Wear protective gloves, eye wear and mask. cause harm to the eyes and skin.
Page 34 TURN POWER ON; LAMP LEDS NOT LIT CONNECTORS FOR ALL THE CHECK LAMP LEDS LAMPS ARE PROPERLY ENGAGED LAMP LEDS LIT? CALL LENNOX TWO PAIR, PIN TO PIN TECH SUPPORT ON EACH PAIR 1-800-453-6669 (SEE DETAIL A) LAMPS BANDS CONTINUITY...
Page 35: Field-Installed Accessories
TABLE 13 Field-Installed Accessories LDT/LHT 092 (2-Compressor) Staged Direct Drive When field-installing the following accessories, refer to Field Para Factory the latest online installation instruction. mete Setting Description Setting TABLE 12 Note: Any changes to Smoke CFM setting must be adjusted be Accessory Instruction # fore the other CFM settings.
Page 36 TABLE 14 TABLE 15 LDT/LHT 102 (2-Compressor) Staged Direct Drive LDT/LHT 120 (2-Compressor) Staged Direct Drive Field Para Field Para Factory Factory mete Setting Description meter Setting Setting Setting Description Note: Any changes to Smoke CFM setting must be adjusted be Note: Any changes to Smoke CFM setting must be adjusted fore the other CFM settings.
Page 37 TABLE 16 TABLE 17 581037-01 LDT/LHT 150 (2-Compressor) Staged Direct Drive Units With LonTalk Settings Field Para Factory meter Setting Description Setting Use menu RTU Menu > Network Integration > Network Setup Wizard > Set “LONTALK” Note: Any changes to Smoke CFM setting must be adjusted before the other CFM settings.
Page 38 Dual-Stage = D U = Unconfigured Unconfigured = U Power Exhaust Control 4] [5] Network Module Not Installed = N N = Not Installed Damper Position = A L = LonTalk (Lennox) A34 Pressure Sensor = C FIGURE 36 Page 38...
Page 39 Phase / Voltage Detection * [5] [6] IAQ Options N = Not Installed N = Not Installed 1 = Enabled Internal (Lennox) 1 = UV Lamp Installed 2 = External (A42) Phase Detection 2 = Bipolar Ionizer Installed on DI-2...
Page 40 START-UP REPORT Job Name:___________________________________ Inspections and Checks Store No.___________Start-Up Date:______________ R22 j R410A j Damage? If yes, reported to:____________________________ Address:_____________________________________ City:______________________________State:______ Verify factory and field-installed accessories. Start-Up Contractor:____________________________ Check electrical connections. Tighten if necessary. Technician:___________________________________ Supply voltage: L1-L2______L1-L3_____L2-L3_____ Model No.:___________________________________ If unit contains a 208-230/240 volt transformer: Serial No.:____________________________________ Check primary transformer tap j...

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Lennox LHT078H Installation Instructions Manual

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