Lennox LGH240H

Page 1
UNIT INFORMATIONUNIT INFORMATION
Service Literature
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
maintenance), 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.
CAUTION
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.
WARNING
Improper installation, adjustment, alteration,
service or maintenance can cause property damage,
personal injury or loss of life. Installation and service

agency.
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
Options / Accessories . . . . . . . . . . . . . . . . . . . . . Page 2
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Blower Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 15
Electrical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 18
I-Unit Components . . . . . . . . . . . . . . . . . . . . . . . Page 23
II-Placement and Installation . . . . . . . . . . . . . . . Page 46
III-Charging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 46

V-System Service Checks . . . . . . . . . . . . . . . . . Page 83
VI-Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . Page 86
VII-Accessories. . . . . . . . . . . . . . . . . . . . . . . . . . Page 87
The LGH156H, 180H, 180U, 210H, 240H, 240U, 300S

units (CTO) with a wide selection of factory installed op-
tions.
LGH156H is available in 260,000 Btuh or 360,000 Btuh
(76.2 or 105.5 kW) and has the option for single stage

LGH180H, 180U, 210H, 240H, 240U, 300S and 300U
units are available in 260,000, 360,000 or 480,00 Btuh
(76.2, 105.5 or 140.7 kW) heating inputs.
The LGH180H/U and 210H also has an optional single
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Gas heat sections are designed with aluminized steel tube
heat exchangers with stainless steel as an option.
Cooling capacities range from 13 to 25 tons (45.7 to 88
kW). LGH156H, 180H, and 210H utilize three compres-
sors while LGH180U, 240H, 240U, 300S and 300U utilize
four compressors.
Units are designed for R410A refrigerant. See unit name-
plate. Operating pressures and pressure switch settings
       
equipment must be rated for R410A.
Multi-Stage Air Volume MSAV
®
blower option is available.
The VFD-driven blower will operate at lower speeds when
demand is low and increase to higher speeds when de-
mand is high.
Variable speed VAV system is available as an option which
enables supply duct static measurement to control blow-
er CFM and discharge air temperature to control cooling
stages.
󰀨-
ent energy management thermostat control systems with
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tions connect to the unit through Smartwire connectors.
When “plugged in” the controls become an integral part of
the unit wiring.
Information contained in this manual is intended for use
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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.
LGH SERIES
13 to 25 ton
45.7 to 88 kW
Copr 1013-L2
Revised 05/2020
LGH156H through 300U

Lennox LGH240H Specifications

General

Brand	Lennox
Model	LGH240H
Category	Air Conditioner
Language	English

Summary

Service Literature

Safety Warnings

Crucial safety precautions for handling and servicing the unit.

Options Accessories

Specifications

Cooling Performance

Detailed cooling performance metrics and ratings.

Refrigerant Charge

Specifications for refrigerant charge per circuit.

Indoor Blower and Drive Selection

Information on blower motor selection and drive kits.

Specifications - Gas Heat

Blower Data

Factory Installed Belt Drive Kit Specifications

Specifications for factory installed belt drive kits.

Electrical Data

13 Ton High Efficiency Electrical Data

Electrical data for 13-ton high efficiency units.

15 Ton High Efficiency Electrical Data

Electrical data for 15-ton high efficiency units.

17.5 Ton High Efficiency Electrical Data

Electrical data for 17.5-ton high efficiency units.

20 Ton High Efficiency Electrical Data

Electrical data for 20-ton high efficiency units.

25 Ton Standard Efficiency Electrical Data

Electrical data for 25-ton standard efficiency units.

I-Unit Components

Control Box Components

Identification and description of control box components.

Component Descriptions

Control Systems - A55 Unit Controller

Overview of the A55 Unit Controller functions and connectivity.

B-Cooling Components

Compressors B1, B2, B13 and B20

Specifications and characteristics of unit compressors.

High Pressure Switches S4, S7, S28, S96

Details on high pressure switches and their operation.

Low Ambient Switches S11, S84, S85 and S94

Information on low ambient switches for cold weather operation.

OPERATION ADJUSTMENT

Determining Unit Air Volume

Procedure for setting blower CFM to meet design airflow specifications.

D-GAS HEAT COMPONENTS

Safety Warnings for Gas Heat Components

Safety precautions related to high voltage and spark components.

Burner Ignition Control A3, A12

Details on UTEC ignition controls and LED codes.

III-CHARGING

Refrigerant Safety Warning

Important safety warning regarding refrigerant handling.

Aluminum Coils - Charge Verification

Procedure for checking refrigerant charge on aluminum coils.

C-Heating Startup

Safety Warnings Before Lighting

Critical safety warnings to follow before lighting the appliance.

Placing Furnace In Operation

Step-by-step guide for putting the furnace into operation.

Safety or Emergency Shutdown

Instructions for performing a safety or emergency shutdown.

V-SYSTEMS SERVICE CHECKS

Heating System Service Checks

Procedures for servicing the heating system.

Gas Supply Pressure Testing

Procedure for testing and adjusting gas supply pressure.

Manifold Pressure Adjustment

Procedure for checking and adjusting manifold pressure.

B-Cooling System Service Checks

Oil Check Injection Procedure

Procedure for checking and injecting oil into tandem compressors.

VI-MAINTENANCE

Electrical Checks

Routine checks of electrical connections, voltage, and amp-draw.

VII-ACCESSORIES

High Performance Economizer

Description and operation of the high performance economizer.

VIII-FACTORY-INSTALLED Hot Gas Re-Heat

General Hot Gas Re-Heat Operation

Overview of the dehumidifying mode using hot gas reheat.

IX-Staged-Blower Start-Up

Design Specifications for Staged-Blower

Guidelines for filling in field-provided, design specified blower CFM.

Set Maximum CFM

Procedure to determine and set the highest blower CFM.

Enter Design Specifications Into Controller

Instructions for entering blower CFM specifications into the Unit Controller.

Set Damper Minimum Position

Operation

Two-Stage Thermostat Operation

Three-Stage Thermostat Operation

Zone Sensor Operation

XI-Wiring Diagrams and Sequence of Operation

LGH156 UNIT DIAGRAM

Wiring diagram for the LGH156 unit.

LGH156 DIAGRAM KEY DESCRIPTION

LGH180 UNIT DIAGRAM

Wiring diagram for the LGH180 unit.

LGH180 KEY DESCRIPTION

LGH210 UNIT DIAGRAM

Wiring diagram for the LGH210 unit.

LGH210 KEY DESCRIPTION

LGH240300 UNIT DIAGRAM

Wiring diagram for the LGH240/300 units.

LGH240300 KEY DESCRIPTION

Sequence of Operation LGH156300

Sequence of operation for LGH156/300 units.

Sequence of Operation LGH180 U, 240 U, 300 U

Sequence of operation for LGH180U, 240U, 300U units.

Staged-Blower UNITS - NO BYPASS

Staged-Blower UNITS - WITH BYPASS

GAS HEAT DIAGRAM

Wiring diagram specifically for the gas heat components.

SEQUENCE OF OPERATION GAS HEAT FOR LGH156300 UNITS

Detailed sequence of operation for gas heat functionality.

ELECTRONIC OR ELECTROMECHANICAL THERMOSTAT

Wiring diagram for electronic or electromechanical thermostats.

ELECTRONIC OR ELECTROMECHANICAL THERMOSTAT KEY DESCRIPTION

ECONOMIZER SEQUENCE OF OPERATION

Sequence of operation for the economizer system.