Lennox LGH150S

Corp. 1008-L2
LGH SERIES
Service Literature
7.5 to 12.5 ton
38.1 to 70.3 kW
Revised 05/2020
LGH092H through 152U
The LGH092H, 094U, 102H, 120H, 122U, 150S, 150H
and 152U units are configure to order units (CTO) with a
wide selection of factory-installed options. Units are
available in 130,000, 180,000 Btuh or 240,000 Btuh
(38.1, 52.7 or 70.3 kW) heating inputs. Gas heat sec
tions are designed with aluminized steel tube heat ex
changers with stainless steel as an option.
Cooling capacities range from 7.5 to 12.5 tons (38.1 to
70.3 kW). All units are equipped with two compressors.
Ultra-high efficiency units are available with an optional di
rect drive blower or belt drive blower equipped with a sup
ply air inverter. Standard and high efficiency units are
available with a belt drive blower equipped with an option
al supply air inverter. The blower will operate at lower
speeds when demand is low and increase to higher
speeds when demand is high.
The following examples show the model numbers of ten-
ton units with all available blower options:
LGH120H4B High Efficiency Belt Drive
LGH120H4M High Efficiency Belt Drive with Inverter
LGH122U4M Ultra High Efficiency Belt Drive with Inverter
LGH122U4E Ultra High Efficiency Direct Drive
Note - Ten-ton units are available in high and ultra high effi
ciencies only.
Standard and high efficiency units come standard with a
lightweight, all-aluminum condenser coil; optional, fin/
tube condenser coils are available. Ultra-high efficiency
units come standard with a tube/fin condenser coil.
Ultra high efficiency units come standard with two single-
speed compressors plumbed in tandem to form a single re
frigerant circuit.
Units are also designed for R410A refrigerant. See unit
nameplate. Operating pressures and pressure switch set
tings are significantly higher than R22 charged units. Ser
vice equipment must be rated for R410A.
Standard and high efficiency units offer mechanical cooling
down to 0°F when properly equipped. Ultra-high efficiency
units offer mechanical cooling down to 40°F.
All LGH units are designed to accept any of several differ
ent energy management thermostat control systems with
minimum field wiring. Factory or field provided control op
tions connect to the unit with jack plugs. When ”plugged in”
the controls become an integral part of the unit wiring.
Information contained in this manual is intended for use by
qualified service technicians only. All specifications are
subject to change. Procedures outlined in this manual are
presented as a recommendation only and do not super
sede or replace local or state codes.
If the unit must be lifted for service, rig unit by attaching four
cables to the holes located in the unit base rail (two holes at
each corner). Refer to the installation instructions for the
proper rigging technique.
3
3
Table of Contents
Options / Accessories Page 2.....................
Specifications Page 8............................
Blower Tables Page 14............................
Electrical Data Page 19...........................
Parts Arrangement Page 25.......................
I-Unit Components Page 28.......................
II-Placement and Installation Page 47...............
III-Charging Page 47..............................
IV-Start Up - Operation Page 55....................
V-System Service Checks Page 57................
High Altitude Page 59.........................
VI-Maintenance Page 59..........................
VII-Accessories Page 60..........................
VIII-Belt Drive Supply Air Inverter Page 67...........
IX-Direct Drive Supply Air Blower Page 70...........
X-Staged Supply Air Operation Page 71.............
XI-Wiring and Operation Sequence Page 72.........
WARNING
Improper installation, adjustment, alteration, service
or maintenance can cause property va, personal in
jury or loss of life. Installation and service must be
performed by a licensed professional HVAC installer
or equivalent, service agency, or the gas supplier
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.
© 2019

Lennox LGH150S Specifications

General

Brand	Lennox
Model	LGH150S
Category	Air Conditioner
Language	English

Summary

UNIT INFORMATION

WARNING

Highlights critical safety hazards and potential for injury or death.

CAUTION

Warns about potential minor injuries from handling equipment.

SPECIFICATIONS - 092 H, 102 H

SPECIFICATIONS 120 H, 150 H

SPECIFICATIONS - GAS HEAT - 092 H, 102 H, 120 H, 150 H

HIGH ALTITUDE DERATE - 092 H, 102 H, 120 H, 150 H

SPECIFICATIONS - DIRECT DRIVE MODELS

Indoor Blower

SPECIFICATIONS - BELT DRIVE MODELS - 094 U, 122 U, 152 U

General Data

Provides general data for belt drive models, including tonnage and efficiency.

Cooling Performance

Details cooling capacity, airflow, power, and efficiency for belt drive models.

Refrigerant Charge

Specifies refrigerant charge for belt drive models.

Compressor Type (number)

Identifies compressor type for belt drive models.

Indoor Blower and Drive Selection

Covers blower motor output, drive kit numbers, and wheel specifications for belt drive models.

Electrical characteristics

SPECIFICATIONS - GAS HEAT - 094 U, 122 U, 152 U

Gas Heating Performance

Details gas heat input, output, temperature rise, and efficiency.

BLOWER DATA

BLOWER DATA - 092, 094, 102, 120, 122, 150, 152

FACTORY INSTALLED BELT DRIVE KIT SPECIFICATIONS

BLOWER DATA - DIRECT DRIVE - 094 U, 122 U, 152 U

ELECTRICAL DATA

7.5 HIGH EFFICIENCY (R-410 A)

Lists electrical data for 7.5 ton high efficiency units.

10 HIGH EFFICIENCY (R-410 A)

Lists electrical data for 10 ton high efficiency units.

7.5 DIRECT DRIVE

Electrical data for 7.5 ton direct drive models.

12.5 DIRECT DRIVE

Electrical data for 12.5 ton direct drive models.

7.5 BELT DRIVE

Electrical data for 7.5 ton belt drive models.

8.5 HIGH EFFICIENCY (R-410 A)

Lists electrical data for 8.5 ton high efficiency units.

12.5 HIGH EFFICIENCY (R-410 A)

Lists electrical data for 12.5 ton high efficiency units.

10 DIRECT DRIVE

Electrical data for 10 ton direct drive models.

10 BELT DRIVE

Electrical data for 10 ton belt drive models.

I-UNIT COMPONENTS

A-Control Box Components

14-Variable Frequency Drive A96 (optional)

12-Unit Controller A55

Describes the unit controller's functions, diagnostics, and navigation.

PLUMBING, COMPRESSOR AND REFRIGERANT CIRCUITS DETAIL

(HIGH EFFICIENCY ALL-ALUMINUM OUTDOOR COIL)

(OPTIONAL STANDARD EFFICIENCY FINTUBE COIL)

(OPTIONAL ULTRA HIGH EFFICIENCY UNITS WITH FINTUBE COIL)

B-Cooling Components

1-Compressors B1, B2

Details the compressors, their circuits, and capacity.

4-Low Ambient Switches S11, S84

9-Freezestats S49 and S50

3-High Pressure Switches S4, S7

Explains the operation and function of high pressure switches.

7-Low Pressure Switches S87, S88

Details the operation and function of low pressure switches.

DIRECT DRIVE BLOWER ASSEMBLY

OPERATION ADJUSTMENT

Outlines procedures for operating and adjusting the direct drive blower.

OPERATION ADJUSTMENT

Determining Unit Air Volume

Blower Belt Adjustment

PULLEY ALIGNMENT

Check Belt Tension

MEASURE BELT TENSION

D-GAS HEAT COMPONENTS

Burner Ignition Control A3

Details the burner ignition control and its functions.

2-Heat Exchanger (Figures 25 and 26)

5-Primary High Temperature Limits S10

6-Flame Roll-out Limit S47

4-Burner Assembly (Figure 28)

10-Gas Valves GV1

III-CHARGING

A-Refrigerant Charge and Check - All-Aluminum Coil 092 H, 102 H, 120 H, 150 S Units

Provides procedures for refrigerant charge and check for specific units.

B-Refrigerant Charge and Check - FinTube Coil - TXV

B-Refrigerant Charge and Check - FinTube Coil & RFC

LGHLCH150 S

Specifies refrigerant charge and check for LGH/LCH150S units.

G-Refrigerant Charge and Check - FinTube Coil & TXV

LGHLCH094 U, 122 U, 152 U

Specifies refrigerant charge and check for these models.

Charge Verification - Approach Method - AHRI Testing (FinTube Coil Continued)

Details approach method for AHRI testing of refrigerant charge.

IV-START-UP - OPERATION

A-Preliminary and Seasonal Checks

Outlines pre-start-up and seasonal checks for the unit.

B-Cooling Start-up See figure 34, 35 or 36 for Circuits

Provides step-by-step instructions for starting the unit in cooling mode.

REFRIGERANT STAGES - All-Aluminum Coil

REFRIGERANT CIRCUITS - FinTube Coil

REFRIGERANT STAGES - 094 U, 122 U, 152 U TRADITIONAL FINTUBE COIL

C-Heating Start-up

Placing Furnace In Operation

Guides on safely placing the furnace into operation.

Gas Valve Operation for White Rodgers 36 C and Honeywell VR8205 QVR8305 Q (figure 37)

Details gas valve operation for specific control models.

Turning Off Gas to Appliance

Provides instructions for safely turning off the gas supply.

D-Safety or Emergency Shutdown

Outlines procedures for safety and emergency shutdown of the unit.

V-SYSTEMS SERVICE CHECKS

A-Heating System Service Checks

Covers checks for the heating system, including gas piping and pressure.

1-Gas Piping

2-Testing Gas Piping

3-Testing Gas Supply Pressure

Outlines how to test gas supply pressure for proper operation.

8-Heat Exchanger

4-Check and Adjust Manifold Pressure

Details checking and adjusting manifold gas pressure.

9-Flame Sensing

Explains flame sensing and how to measure flame current.

VI-MAINTENANCE

F-Electrical

ECONOMIZER

H-Economizer (all units) (Field or Factory Installed)

Free Cooling Mode

P-Factory Installed-Hot Gas Reheat (optional)

REHEAT MODE REFRIGERANT ROUTING

COOLING MODE REFRIGERANT ROUTING

VIII-Belt Drive Supply Air Inverter

OPERATION

Details the operation of the VFD for staged supply air control.

ADJUST CFM

Provides instructions for setting supply air CFM using the controller.

INPUTS REQUIRED TO STAGE SUPPLY AIR BLOWER

A96 FAULT SEQUENCE:

Describes the sequence of events during an A96 inverter fault.

B-Set Maximum CFM

D-Set Damper Minimum Position

IX-Direct Drive Supply Air Inverter

A-Set Blower Speed

Guides on setting blower speed for direct drive units using the controller.

B-Set Damper Minimum Position

X-Staged Supply Air Operation

A-Two-Stage Thermostat

Summarizes staged operation with a two-stage thermostat.

B-Three-Stage Thermostat OR Zone Sensor

Summarizes staged operation with a three-stage thermostat or zone sensor.

XI-Wiring Diagrams and Sequence of Operation

LGH092102120 H - CONSTANT SUPPLY AIR, BELT DRIVE BLOWER

Provides wiring diagrams for specific units and configurations.

LGH150 H - Y - CONSTANT SUPPLY AIR, BELT DRIVE BLOWER

LGH150 H G, J, M - STAGED SUPPLY AIR, NO BYPASS, BELT DRIVE BLOWER

LGH092102120 H STAGED SUPPLY AIR, WITH BYPASS, BELT DRIVE BLOWER

LGH150 H - Y - STAGED SUPPLY AIR, WITH BYPASS, BELT DRIVE BLOWER

LGH092-152 U STAGED SUPPLY AIR, WITH BYPASS, BELT DRIVE BLOWER

SUPPLY AIR INVERTER - NO BYPASS SEQUENCE OF OPERATION

SUPPLY AIR INVERTER - WITH OPTIONAL FACTORY-INSTALLED BYPASS SEQUENCE OF OPERATION

OPERATION:

Details the operational sequence for the inverter with a factory-installed bypass.

A96 FAULT SEQUENCE:

Describes the fault sequence for the A96 inverter with bypass.

BLOWER FAULT SEQUENCE:

Outlines the sequence of events for blower faults.

Failure HandlingTroubleshooting:

Provides steps for troubleshooting blower assembly failures.

DIRECT DRIVE BLOWER SEQUENCE OF OPERATION TROUBLESHOOTING

Blower Operation:

Describes the operation sequence for direct drive blower motors.

Blower Fault Sequence Direct Drive Motor - No S52:

Details fault sequences for direct drive motors without S52.

Blower Fault Sequence Direct Drive Motor - With S52 (If Configured):

Details fault sequences for direct drive motors with S52.

Failure HandlingTroubleshooting:

Provides troubleshooting steps for blower failures.