E2023 WARNING Improper installation, adjustment, alteration, ser vice or maintenance can cause property damage, personal injury or loss of life. Installation and ser vice must be performed by a licensed professional HVAC installer or equivalent, service agency, or the gas supplier LHT/LDT180 (15 Ton) LHT/LDT240 (20 Ton) HEAT PUMP AND DUAL-FUEL PACKAGED UNITS 508336-01 1/2023 Supersedes 12/2022 Table of Contents Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
WARNING To prevent serious injury or death: 1- Lock-out/tag-out before performing maintenance. 2- If system power is required (e.g., smoke detector mainte nance), disable power to blower, remove fan belt where applicable, and ensure all controllers and thermostats are set to the “OFF” position before performing maintenance. 3- Always keep hands, hair, clothing, jewelry, tools, etc., away from moving parts.
LHT180, 240 PARTS ARRANGEMENT INDOOR COIL FILTERS (SIX - 24 X 24 X 2”) OUTDOOR FANS BLOWERS ECONOMIZER DAMPERS (OPTIONAL) BLOWER MOTOR BLOWER INVERTER 8.8.8.8 UNIT CONTROLLER CONDENSATE DRAIN OUTDOOR COILS COMPRESSORS DISCONNECT (FACTORY-INSTALLED OPTION) ELECTRIC HEAT LDT180, 240 PARTS ARRANGEMENT FILTERS (SIX - 24 X 24 X 2”) INDOOR COIL OUTDOOR FANS BLOWERS ECONOMIZER DAMPERS (OPTIONAL) BLOWER MOTOR BLOWER INVERTER 8.8.8.
Shipping and Packing List Requirements Package 1 of 1 contains: 1- Assembled unit Check unit for shipping damage. Receiving party should contact last carrier immediately if shipping damage is found. See figure 1 for unit clearances. General UNIT CLEARANCES These instructions are intended as a general guide and do not supersede local codes in any way. Authorities having jurisdiction should be consulted before installation.
NOTICE Roof Damage! This system contains both refrigerant and oil. Some rubber roofing material may absorb oil, causing the rubber to swell. Bubbles in the rubber roofing material can cause leaks. Protect the roof surface to avoid exposure to refrigerant and oil during service and installation. Failure to follow this notice could result in damage to roof surface. Use of this unit as a construction heater or air conditioner is not recommended during any phase of construction.
5- Units require support along all four sides of unit base. Supports must be constructed of steel or suitably treated wood materials. NOTE-When installing a unit on a combustible surface for downflow discharge applications, an LARMF18/36 roof mounting frame is required. B-Horizontal Discharge Applications 1- Units installed in horizontal airflow applications must use an LARMFH18/24 horizontal roof mounting frame. The supply air duct connects to the horizontal supply air opening on the LARMFH18/24.
Condensate Drains CONDENSATE DRAIN CONNECTION Remove cap and make drain connection to the 1” N.P.T. drain coupling provided on unit. A trap must be installed between drain connection and an open vent for proper condensate removal. See figure 3. It is sometimes acceptable to drain condensate onto the roof or grade; however, a tee should be fitted to the trap to direct condensate downward. The condensate line must be vented. Check local codes concerning condensate disposal.
BOTTOM ENTRY GAS PIPING Connect Gas Piping Before connecting piping, check with gas company or authorities having jurisdiction for local code requirements. When installing gas supply piping, length of run from gas meter must be considered in determining pipe size for 0.5” w.c. (.12kPa) maximum pressure drop. Do not use supply pipe smaller than unit gas connection. For natural gas units, operating pressure at the unit gas connection must be a minimum of 4.7” w.c. (1.17kPa) and a maximum of 10.5” (2.
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. S Minimum Android 6.0 (Marshmallow) or higher. Recommend Android 10 and Apple products require iOS version 11 or higher. MANUAL MAIN SHUT-OFF VALVE B-New Installations GAS VALVE Once the app is downloaded, refer to the Setup Guide provided with this unit to pair the app to the unit control system.
B-Unbalanced Three-Phase Voltage Electrical Connections - Power Supply A-Wiring Route field wiring in conduit between bottom power entry and disconnect. See figure 8. This does not supersede local codes or authorities having jurisdiction. Do not apply power or close disconnect switch until installation is complete. Refer to start-up directions. Refer closely to unit wiring diagram. Refer to unit nameplate for minimum circuit ampacity and maximum fuse size.
C-Wire Connections 2- Zone Sensor Mode - The Unit Controller will operate the unit from a thermostat or zone sensor based on the System Mode. The default System Mode is the thermostat mode. Refer to the Unit Controller Setup Guide to change the System Mode. Use the mobile service app menu and select: SETTINGS > INSTALL. Note - Unit Controller is capable of up to four stages of cooling in network control mode.
Blower Operation and Adjustments WARNING Supply Air Staged Units - The blower rotation will always be correct on units equipped with an inverter. Checking blower rotation is not a valid method of determining voltage phasing for incoming power. 1-Make sure that unit is installed in accordance with the installation instructions and applicable codes. 2-Inspect all electrical wiring, both field‐ and factory‐ installed, for loose connections. Tighten as required.
TABLE 3 MINIMUM AND MAXIMUM PULLEY ADJUSTMENT 4- The blower RPM can be adjusted at the motor pulley. Loosen Allen screw and turn adjustable pulley clockwise to increase CFM. Turn counterclockwise to decrease CFM. See figure 12. Do not exceed minimum and maximum number of pulley turns as shown in table 3. Belt Minimum Turns Open Maximum Turns Open A Section No minimum 5 B Section 1* 6 *No minimum number of turns open when B belt is used on pulleys 6” O.D. or larger.
D-Blower Belt Adjustment E-Check Belt Tension Maximum life and wear can be obtained from belts only if proper pulley alignment and belt tension are maintained. Tension new belts after a 24-48 hour period of operation. This will allow belt to stretch and seat into pulley grooves. Make sure blower and motor pulley are aligned. See figure 13. Overtensioning belts shortens belt and bearing life. Check belt tension as follows: 1- Measure span length X. See figure 14.
BLOWER DATA BLOWER TABLE INCLUDES RESISTANCE FOR BASE UNIT ONLY WITH DRY INDOOR COIL & AIR FILTERS IN PLACE FOR ALL UNITS ADD: 1 - Wet indoor coil air resistance of selected unit. 2 - Any factory installed options air resistance (electric heat, economizer, etc.) 3 - Any field installed accessories air resistance (electric heat, duct resistance, diffuser, etc.) Then determine from blower table blower motor output and drive required. See page 16 for wet coil and option/accessory air resistance data.
BLOWER DATA FACTORY INSTALLED BELT DRIVE KIT SPECIFICATIONS Motor Efficiency Nominal hp Maximum hp Drive Kit Number RPM Range 3 3 5 5 5 7.5 7.5 7.5 10 10 10 3.45 3.45 5.75 5.75 5.75 8.63 8.63 8.63 11.50 11.50 11.
TABLE 4 MANUFACTURER'S NUMBERS DRIVE COMPONENTS Drive No. RPM H.P. ADJUSTABLE SHEAVE FIXED SHEAVE BELTS (STD.) BELTS (WITH TENSIONER) SPLIT BUSHING Min Max Supplier No. OEM Part No. Supplier No. OEM Part No. Supplier No. OEM Part No. Supplier No. OEM Part No. Supplier No. OEM Part No.
1- Initiate first and second stage cooling demands using this mobile service app menu path: Cooling Start-Up IMPORTANT-The crankcase heater must be energized for 24 hours before attempting to start compressor. Set thermostat so there is no demand to prevent compressors from cycling. Apply power to unit. NOTE - These units must not be used as a “construction heater” at any time during any phase of construction.
REFRIGERANT CIRCUITS INDOOR COIL CIRCUIT 1 & 2 ARE INTERLACED CIRCUIT 1 OUTDOOR COIL CIRUIT 2 OUTDOOR COIL FIGURE 15 D-Refrigerant Charge and Check - Fin/Tube Coil WARNING-Do not exceed nameplate charge under any condition. This unit is factory charged and should require no further adjustment. If the system requires additional refrigerant, reclaim the charge, evacuate the system and add required nameplate charge. NOTE - System charging is not recommended below 60°F (15°C).
TABLE 6 240 Compressor 1 Frequency 68Hz - 581169-01 Outdoor Coil En tering Air Temp Dis +10 psig Suc +5 psig Dis. +10 psig Suc +5 psig 65 °F 75 °F 85 °F 95 °F 105 °F 115 °F 260 297 338 384 434 485 135 136 138 140 142 144 264 304 346 394 443 494 135 136 138 140 142 144 Circuit 1 Circuit 2 E-Charge Verification - Approach Method - AHRI Testing (Fin/Tube Coil) 1- Using the same thermometer, compare liquid temperature to outdoor ambient temperature.
Heating Start-Up (LDT) WARNING FOR YOUR SAFETY READ BEFORE LIGHTING BEFORE LIGHTING smell all around the appliance area for gas. Be sure to smell next to the floor because some gas is heavier than air and will settle on the floor. Danger of explosion. Can cause injury or death. Do not attempt to light manually. Unit has a direct spark ignition system. A-Placing Unit In Operation Use only your hand to push in or turn the gas control knob. Never use tools.
11- The ignition sequence will start. C-Heating Adjustment 12- If the appliance does not light the first time (gas line not fully purged), it will attempt up to two more ignitions before locking out. Main burners are factory-set and do not require adjustment. 13- If lockout occurs, repeat steps 1 through 10. 14- If the appliance will not operate, follow the instructions “Turning Off Gas to Appliance” and call your service technician or gas supplier.
Defrost Control The defrost control ensures that the heat pump outdoor coil does not ice excessively during the heating mode. Defrost is enabled below 35°F. The Unit Controller will cycle in and out of defrost depending on the temperature difference between the outdoor coil and outdoor air temperature. If the system fails to calibrate or obtain readings for demand defrost, defrost will run-time at the field setting.
TABLE 8 Blower CFM Design Specifications Multi-Staged Air Volume Start-Up A-Design Specifications Use table 8 to fill in field-provided, design specified blower CFM for appropriate unit. If only high and low cooling design specifications are provided, set the medium cooling CFM at the high or low cooling design spec or any CFM between. B-Set Maximum CFM Use table 8 to determine highest blower CFM for appropriate unit. Adjust the blower pulley to deliver that amount of CFM with only the blower operating.
TABLE 9 HEATING, VENTILATION & SMOKE MINIMUM AND MAXIMUM CFM Unit Model LDT180H LHT180H LDT240H LHT240H Heating CFM Speed Heat Code Low Std Med High HP W/O EH 15, 30, 45, 60, 90 KW Low, Std, Med High HP W/O EH 15, 30, 45, 60, 90 KW L S M H N E, J, K, L, P L, S, M H N E, J, K, L, P Default 6000 8000 Min 2725 4325 4500 5125 4500 6000 4500 5125 6000 6000 *Use highest value between Heating and Cooling High CFM Max.
B-Three-Stage Thermostat Multi-Staged Air Volume Operation This is a summary of cooling operation. Refer to the sequence of operation provided in the Engineering Handbook or Service Manual for more detail.
Temperature Thermistor Sensors Units are equipped with four factory-installed thermistors (RT46 - RT49) located on different points on the refrigerant circuit. feedback in certain modes of unit operation. In addition, the Unit Controller uses these temperatures to initiate alarms such as loss of outdoor or indoor coil airflow and loss of charge. Each thermistor must be specifically placed for proper unit operation and to initiate valid alarms.
THERMISTOR LOCATION OUTDOOR COIL (RT48, RT49) YELLOW RT48 BLUE RT49 FIGURE 20 Page 28 LHT/LDT180, 240
C-Burners (Gas Units) Service The unit should be inspected once a year by a qualified service technician. A-Filters Units are equipped with six 24 X 24 X 2” filters. Filters should be checked monthly and replaced when necessary with filters of like kind and size. Take note of air flow direction marking on filter frame when reinstalling filters. See figure 21. NOTE-Filters must be U.L.C. certified or equivalent for use in Canada.
Under normal operating conditions, the combustion air inducer wheel should be checked and cleaned prior to the heating season. However, it should be examined periodically during the heating season to establish an ideal cleaning schedule. With power supply disconnected, the condition of the inducer wheel can be determined by looking through the vent opening. IGNITOR SPARK GAP SHOULD BE 1/8” (3mm) Clean combustion air inducer as follows: 1- Shut off power supply and gas to unit.
INDOOR AIR QUALITY (CO2) SENSOR HEAT EXCHANGER ASSEMBLY HEAT EXCHANGER TUBE COMBUSTION AIR INDUCER SUPPLY AND RETURN AIR IAQ SENSORS VENT CONNECTOR GAS VALVE BURNER FIGURE 25 E-Flue Passageway and Flue Box (Gas Units) 1- Remove combustion air inducer assembly as described in section D. 2- Remove flue box cover. Clean with a wire brush as required. 3- Clean tubes with a wire brush. 4- Reassemble the unit.
INSTALL IONIZER 20 TON SHOWN (5 IONIZERS) REMOVE THE SCREW SECURING THE TOP OF THE UPPER FILTER RACK BRACKET ONE EDGE PROTECTOR ON IONIZER BRACKET INDOOR COIL REMOVE THE SCREW SECURING THE BOTTOM OF THE UPPER FILTER RACK BRACKET TWO EDGE PROTECTORS ON FILTER RACK IONIZER BRACKET UPPER FILTER BRACKET U-CHANNEL SLIDE IONIZER BRACKET BETWEEN UPPER AND LOWER FILTER BRACKET U-CHANNELS LOWER FILTER BRACKET U-CHANNEL FIGURE 27 Page 32 LHT/LDT180, 240
L-UVC Light (Optional) When field-installed, use only UVC Light Kit assembly 106883-01 (21A94) with this appliance. 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 UVC light assembly on the blower deck. Remove the lamp and install into the UVC light assembly as shown in steps 2 through 11 as follows. 6- Allow 10 minutes before touching the lamps.
8- Carefully place the UVC assembly on the blower deck. Line up the mounting holes on the UVC assembly with the mounting holes on the blower deck. Use the retained #10 screws to attach the UVC assembly in place. 9- Close the blower access door. 10- Reconnect power to the rooftop unit. 11- Open the filter access door and look through the view port in the triangular sheet-metal panel to verify that the UVC light is on. For all maintenance, contact a licensed HVAC technician.
TABLE 14 - 581182-01 Staged Blower Parameters Para meter Factory Setting 180H 240H Field Setting Description Note: Any changes to Smoke CFM setting must be adjusted before the other CFM settings. Use SETTINGS > RTU OPTIONS > EDIT PARAMETERS 12 6000 CFM 8000 CFM CFM Blower CFM during smoke detection. SETUP > TEST & BALANCE (can also use SETTINGS > RTU OPTIONS > BLOWER > SPEEDS) 17 3900 CFM 5200 CFM CFM Blower CFM during COOLING LOW operation.
Configuration ID 1 1 2 3 4 5 6 7 8 [8] Outdoor Air CFM Control Humiditrol [1] Not Installed = N N = Not applicable (for future use) Humiditrol Installed = H Unconfigured = U L = Outdoor Air Control Installed with A24 Sensor set for low range. Economizer [2] M = Outdoor Air Control Installed with A24 Sensor set for medium range. Not Installed = N H = Outdoor Air Control Installed with A24 Sensor set for high range.
Configuration ID 2 1 2 3 4 5 6 7 8 9 10 Air Flow Proving [1] Switch (S52) [10] Reserved N = Not Installed Not Installed = N Installed on M4 = C Installed on DDC Controller = D [9] Electric Heat (Field-Installed) N = Not Installed Dirty Filter Switch (S27) [2] Y = Installed Not Installed = N Installed on M4 = C [8] Load Shedding Installed on DDC Controller = D N = Not Installed Overflow Switch [3] (S149 / S179) G = Global (P297 - pin 9) 2 = Installed on DI-2 Not Installed = N 3 = Installed on DI
START-UP REPORT Job Name:___________________________________ Inspections and Checks Store No.___________Start-Up Date:______________ Damage? Yes No R22 j R410A j If yes, reported to:____________________________ Address:_____________________________________ City:______________________________State:______ Verify factory and field-installed accessories. Start-Up Contractor:____________________________ Check electrical connections. Tighten if necessary.
