Lennox LGT150H4E - 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

Cooling Performance

Cooling performance metrics and data.

Refrigerant Charge

Refrigerant type and charge quantities.

Compressor Type (number)

Details on compressor types used in units.

Outdoor Coils

Specifications for outdoor coil components.

Indoor Coil

Specifications for indoor coil components.

HIGH ALTITUDE DERATE

Derating information for high altitude installations.

ELECTRICAL DATA

Maximum Overcurrent Protection (MOCP)

Maximum overcurrent protection specifications.

Minimum Circuit Ampacity (MCA)

Minimum circuit ampacity specifications.

I-UNIT COMPONENTS

Temperature Sensors

Details on temperature sensor types and resistance.

Room Sensors

Information on room sensors used in the unit.

Carbon Dioxide Sensor

Details regarding the carbon dioxide sensor.

VAV Supply Static Sensor

Information on VAV supply static pressure sensor.

PLUMBING, COMPRESSOR AND REFRIGERANT CIRCUITS DETAIL

1-Compressors B1, B2

Details on the unit's compressors.

3-High Pressure Switches S4, S7

Information on high-pressure switches.

5-Low Pressure Switches S87, S88

Information on low-pressure switches.

7-Temperature Sensors RT46, RT47, RT48 & RT49

Information on temperature sensors.

DIRECT DRIVE PARAMETER SETTINGS

Set Minimum Position 1

Setting for minimum blower damper position 1.

Set Minimum Position 2

Setting for minimum blower damper position 2.

D-GAS HEAT COMPONENTS

Burner Ignition Control A3

Description of the burner ignition control.

2-Heat Exchanger (Figure 14)

Details on the heat exchanger assembly.

5-Primary High Temperature Limits S10

10-Gas Valves GV1

II-PLACEMENT AND INSTALLATION

A-Refrigerant Charge and Check

Procedure for checking refrigerant charge.

IV-START-UP - OPERATION

A-Preliminary and Seasonal Checks

B-Cooling Start-up

Procedure for starting the cooling system.

C-Heating Start-up

Procedure for starting the heating system.

Placing Furnace In Operation

D-Safety or Emergency Shutdown

V-SYSTEMS SERVICE CHECKS

A-Heating System Service Checks

Service checks for the heating system.

4-Check and Adjust Manifold Pressure

9-Flame Sensing

VI-MAINTENANCE

A-Filters

R- UVC Light

Annual Lamp Replacement

Maintenance

General maintenance instructions for UVC light.

VIII-Direct Drive Supply Air Inverter

A-Set Blower Speed

Procedure to set blower speed for CFM.

IX-Staged Supply Air Operation

A-Two-Stage Thermostat

B-Three-Stage Thermostat OR Zone Sensor

X-Wiring Diagrams and Sequence of Operation

GAS HEAT FOR LGT092 H-150 H UNITS Y and G Voltage

Cooling Diagram with Higher SCCR

GAS HEAT SEQUENCE OF OPERATION LGT092 H-150 H

First Stage Heat:

Second Stage Heat:

Lennox LGT150H4E Specifications

General

Brand	Lennox
Model	LGT150H4E
Category	Air Handlers
Language	English