Lennox KGA150S4B - User Manual

Page 1
© 2015.
Corp. 1010-L8
Revised 07/2015
KGA UNITS
Service Literature
7.5 to 12.5 ton
26.3 to 42 kW
KGA092 through 150
The KGA 7.5, 8.5, 10 and 12.5 ton (092, 102, 120, 150)
packaged gas units are available in standard cooling effi
ciency. Units are available in 130,000, 180,000 or
240,000Btuh (38.1, 52.7 or 70.3 kW) heating inputs. Gas
heat sections are designed with aluminized steel tube heat
exchangers.
All KGA units are designed to accept any of several different
energy management thermostat control systems with mini
mum field wiring. Factory- or field-provided control options
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 sub
ject to change. Procedures outlined in this manual are pre
sented as a recommendation only and do not supersede 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.
WARNING
Improper installation, adjustment, alteration, service
or maintenance can cause property damage, person
al injury or loss of life. Installation and service must
be performed by a qualified installer or service
agency.
CAUTION
Electrostatic discharge can affect electronic
components. Take precautions during unit instal
lation and service to protect the unit's electronic
controls. Precautions will help to avoid control
exposure to electrostatic discharge by putting
the furnace, the control and the technician at the
same electrostatic potential. Neutralize electro
static charge by touching hand and all tools on an
unpainted unit surface, such as the gas valve or
blower deck, before performing any service pro
cedure.
ELECTROSTATIC DISCHARGE (ESD)
Precautions and Procedures
CAUTION
Danger of sharp metallic edges. Can cause injury.
Take care when servicing unit to avoid accidental
contact with sharp edges.
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 discon
nect switch(es). Unit may have multiple
power supplies.
Options / Accessories Page 2.......................
Specifications Page 5...............................
Blower Data Page 7................................
Electrical Data Page 12.............................
Parts Arrangement Page 14.........................
I- Unit Components Page 15.......................
II- Placement and Installation Page 24...............
III- Start-Up Page 24...............................
IV- Charging Page 26..............................
V- System Service Checks Page 27.................
VI- Maintenance Page 29...........................
VII- Accessories Page 31............................
VIII-Wiring Diagrams Page 39........................

Lennox KGA150S4B Specifications

General

Brand	Lennox
Model	KGA150S4B
Category	Air Conditioner
Language	English

Summary

Unit Specifications

Electrical Characteristics

Lists electrical requirements for the unit.

Gas Heat Specifications

Electrical Data

Electrical Data: 7.5 Ton

Electrical data for 7.5 ton standard efficiency units.

Electrical Data: 10 Ton

Electrical data for 10 ton standard efficiency units.

Electrical Data: 8.5 Ton

Electrical data for 8.5 ton standard efficiency units.

Electrical Data: 12.5 Ton

Electrical data for 12.5 ton standard efficiency units.

Unit Components

Control Box Components Overview

Details components within the unit's control box.

Cooling Components

Compressor and Protection Components

Details compressors, thermal protectors, freezestats, and high-pressure switches.

Blower Compartment and Operation

Blower Operation and Adjustment

Instructions for blower operation and adjustment.

Determining Unit CFM

Blower Belt Adjustment Procedures

Belt Adjustment and Alignment

Checking Belt Tension

Gas Heat Components

Heat Exchanger and Burner Box

Gas Heat Sequence of Operation

Combustion Air and Gas Valve Control

First and Second Stage Heat Sequences

Describes operation for first and second stage heating.

Heat Stage End and Low Ambient Kit

Ignition and Control System

Spark Electrode and Flame Sensor

Burner Control Module (A3)

Details the burner control module functions and status indicators.

Burner Control Module Operation

Flame Rectification and Control Logic

Unit Operation Sequences

Placement, Installation, and Startup

Unit Placement and Installation

Startup and Seasonal Checks

Procedures for unit startup and seasonal checks.

Heating Startup and Safety

Steps for starting heating and related safety precautions.

Gas Valve Operation and Cooling Startup

Gas Valve Operation Details

Details operation of White Rodgers and Honeywell gas valves.

Cooling Startup Procedures

Procedures for starting the cooling function.

Refrigerant Circuits and Charging

Refrigerant Circuit Diagrams

Safety Shutdown and Charging Procedures

Procedures for unit safety shutdown and refrigerant charging.

Gas Piping and System Service Checks

Gas Piping Installation and Testing

Information on gas supply piping and leak testing.

Gas Supply Pressure Testing

Procedures for testing gas supply pressure.

Heating System Service Checks

Manifold Pressure and Gas Flow

Manifold Pressure Check and Adjustment

Procedures for checking and adjusting manifold pressure.

High Altitude Derating and Gas Flow

Heat Exchanger Access and Removal

Flame Sensing and Maintenance

Flame Sensing Procedures

Cooling System Service Checks

General Unit Maintenance

Covers filter replacement, lubrication, and coil cleaning.

Component Maintenance

Burner and Combustion Air Inducer Maintenance

Flue, Condenser Coil, and Blower Wheel

Unit Accessories

Mounting Frames and Transitions

Diffusers and Outdoor Air Dampers

Economizer and Sensor Information

Economizer Unit Details

Enthalpy Control and Free Cooling

Enthalpy Control Module and LEDs

Free Cooling Setpoint Adjustment

Fresh Air Calculation and Economizer Operation

Minimum Fresh Air Calculation

DCV Settings and Economizer Modes

Outdoor Air and Exhaust Dampers

Outdoor Air Dampers

Gravity Exhaust Dampers

Power Exhaust Fan and Controls

Power Exhaust Fan Setpoint Adjustment

Thermostats and Optional Kits

Electronic and Honeywell Thermostats

Wiring Diagrams and Component Key

Unit Wiring Diagram

Detailed wiring diagram for the unit.

Unit Sequence of Operation

Power, Blower, and Economizer Sequences

Cooling Stage Sequences

Sequences for first and second stage cooling operation.

Gas Heat Wiring and Unit Type

Gas Heat Wiring Diagram

Wiring diagram for the gas heat section.

Thermostat Wiring and Operation

Thermostat Wiring Diagram and Components

Wiring diagram and components for thermostats.

Thermostat Power and Operation

Economizer System

Economizer Wiring and Components

Wiring diagram and components for the economizer.

Economizer Sequence of Operation

Describes economizer power supply and operational sequences.