Lennox LGT156H User Manual

2022
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
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.
Table of Contents
Dimensions Page 2.................................
Parts Arrangements Page 5.........................
Shipping and Packing List Page 6....................
General Page 6....................................
Unit Support Page 7................................
Duct Connection Page 8............................
Rigging Unit For Lifting Page 8.......................
Condensate Drains Page 8..........................
Gas Piping Page 9.................................
Pressure Test Gas Piping Page 9.....................
High Altitude Derate Page 10.........................
Download Mobile Service App Page 10.................
Electrical Connections - Power Supply Page 11.........
INSTALLATION
INSTRUCTIONS
LGT/LCT156H
LGT/LCT180H
LGT/LCT210H
LGT/LCT240H
LGT/LCT300S
(13 Ton)
(15 Ton)
(17.5 Ton)
(20 Ton)
(25 Ton)
ROOFTOP PACKAGED UNITS
508288-01
9/2022
Electrical Connections - Control Wiring Page 12.........
Blower Operation and Adjustments Page 13............
Cooling Start-Up Page 20............................
Temperature Thermistor Sensors Page 51..............
Gas Heat Start-Up Page 58...........................
Heating Operation and Adjustments Page 59............
Electric Heat Start-Up Page 59........................
Multi-Staged Air Volume Start-Up Page 60..............
Multi-Staged Air Volume & VAV Operation Page 62......
Hot Gas Reheat Start-Up Page 73.....................
Service Page 77....................................
Unit Controller Parameter Settings Page 82.............
RETAIN THESE INSTRUCTIONS FOR FUTURE REFERENCE
Use this QR code to download the mobile service app. Follow the prompts
to pair the app with the unit control system and configure the unit. Refer to the
“Download Mobile App” section in this manual and the Setup Guide provided
with this unit. The QR code is also available in the unit control area.
The app can be downloaded from the appropriate iOS or Android store.
Look for the following icon.
Attention!

Lennox LGT156H Specifications

General

Brand	Lennox
Model	LGT156H
Category	Air Conditioner
Language	English

Summary

Installation Instructions

Unit Dimensions

Provides physical dimensions for LGT/LCT unit models.

Parts Arrangement

Illustrates the internal components and their layout within the unit.

Shipping and Packing List

Details the contents of the unit shipment and inspection for damage.

Unit Support and Rigging

Guidance on proper unit support, mounting, and rigging for safe installation.

Duct Connection

Procedures for connecting supply and return air ducts to the unit.

Gas Piping and Testing

Instructions for connecting gas piping, pressure testing, and high altitude derates.

Electrical Connections

Procedures for connecting power supply and control wiring to the unit.

Blower Operation and Adjustment

Steps for setting blower speeds, CFM, and adjusting belt tension.

Cooling Start-Up

Procedure for starting up the unit in cooling mode, including refrigerant handling.

Compressor Controls and Fan Operation

Details on compressor protection, fan sequencing, and prognostic sensors.

Gas Heat Start-Up

Step-by-step guide for starting the gas heating section, including operation and adjustments.

Multi-Staged Air Volume Operation

Configuration and setup for multi-stage air volume control and damper settings.

Hot Gas Reheat Start-Up

Procedure for starting up the hot gas reheat dehumidification mode.

Service and Maintenance

Routine inspection, cleaning, and maintenance procedures for unit components.

Factory Unit Controller Settings

Information on default and configurable settings for the unit controller.

Unit Configuration ID Settings

Explanation of configuration IDs for optional kits and accessories.

Start-Up Report

A checklist and form for recording start-up and inspection data.