Lennox LGT092H4E - User Manual

Page 1
UNIT INFORMATIONUNIT INFORMATION
Service Literature
WARNING
Improper installation, adjustment, alteration,
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
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.
Table of Contents
Options / Accessories . . . . . . . . . . . . . . . . . . . . . Page 2

Blower Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 8
Electrical Data . . . . . . . . . . . . . . . . . . . . . . . . . . Page 11
Parts Arrangement . . . . . . . . . . . . . . . . . . . . . . . Page 13
I-Unit Components . . . . . . . . . . . . . . . . . . . . . . . Page 14
II-Placement and Installation . . . . . . . . . . . . . . . Page 29
III-Charging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 29
IV-Start Up - Operation . . . . . . . . . . . . . . . . . . . . Page 34
V-System Service Checks . . . . . . . . . . . . . . . . Page 36
VI-Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . Page 39
VII-Accessories . . . . . . . . . . . . . . . . . . . . . . . Page 39
VIII-Direct Drive Supply Air Blower . . . . . . . . . . Page 49


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.
       
(CTO) with a wide selection of factory-installed options.

         
sections are designed with aluminized steel tube heat ex-
changers with stainless steel as an option.

are equipped with two compressors.
All models are equipped with direct drive blowers. 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 tenton
units with all available blower options:

LGT12w are equipped with all aluminum condenser
coils with one two stage scroll compressor and one


        
nameplate. Operating pressures and pressure switch set-
-

󰀨-
ent energy management thermostat control systems with
-
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

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.

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.
LGT SERIES
7.5 to 12.5 ton

LGT092H through 150H

Summary

SPECIFICATIONS

General Unit Specifications

Provides overall unit data like tonnage, model numbers, and efficiency.

Cooling Performance Data

Details cooling capacity, airflow, and power consumption.

ELECTRICAL DATA

Voltage and Amperage Ratings

Lists voltage, amperage, and circuit protection data for various models.

UNIT COMPONENTS

Control Box Components Overview

Lists and describes components located within the unit's control box.

PLUMBING, COMPRESSOR AND REFRIGERANT CIRCUITS

Cooling System Components

Description of cooling circuit components including compressors and coils.

GAS HEAT COMPONENTS

Ignition Control and Burner System

Details on ignition control, burner assemblies, and safety limits.

Heat Exchanger Details

Information on heat exchanger types, construction, and inserts.

Safety Limits and Sensors

Combustion Air System

PLACEMENT AND INSTALLATION

Refrigerant Charging Procedure

Step-by-step guide for checking and adjusting refrigerant charge.

SYSTEMS SERVICE CHECKS

Heating System Service Checks

Procedures for checking gas piping, supply pressure, and manifold pressure.

Cooling System Service Checks

Procedures for checking cooling system operation and refrigerant charge.

DIRECT DRIVE BLOWER OPERATION

Setting Supply Air CFM

Procedure for setting supply air CFM using the Unit Controller.

Setting Damper Minimum Position

WIRING DIAGRAMS AND SEQUENCES

Gas Heat Wiring Diagrams

Diagrams illustrating gas heat wiring connections for different voltages.

GAS HEAT SEQUENCE OF OPERATION

Heating Stage Sequences

Describes the operation sequence for first, second, and third stage heat.

UNIT SEQUENCE OF OPERATION

Power and Blower Operation

Economizer and Cooling Sequences

Outlines operation for economizer and multi-stage cooling.

BLOWER SEQUENCE AND TROUBLESHOOTING

Blower Operation Sequence

Blower Fault Troubleshooting

Guides for diagnosing and resolving blower motor faults and alarms.

Lennox LGT092H4E Specifications

General

Brand	Lennox
Model	LGT092H4E
Category	Air Handlers
Language	English