Lennox KGB074S4B User Manual

Page 1
100004
KGB SERIES
Service Literature
2 to 7-1/2 ton
7 to 26 kW
May 2020
KGB024 through 090
The KGB packaged gas units are available in standard
cooling efficiency (024, 030, 036, 048 060, 072, 074 and
090). Cooling capacities range from 2 to 7-1/2 tons (7 to
26kW).
KGB024, 030, 036, 048, 060, 072, 074 units are avail
able in 65,000 BTUH heat capacity /KGB036, 048, 060,
072, 074 and 090 units are available in 108,000 BTUH
(105,000 BTUH in earlier built units ) heat capacity.
KGB048, 060, 072, 074 and 090 units are available in
150,000 BTUH (44 kW) heat sizes. Two stage heat is
available in units with 108,000 (105,000 in earlier built
units) and 150,000 BTUH capacities. Gas heat sections
are designed with aluminized steel tube heat exchang
ers.
Information contained in this manual is intended for use by
qualified service technicians only. All specifications are
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.
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 licensed professional installer (or
equivalent), service agency or the gas supplier.
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.
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.
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
Table of Contents
Options Page 2.......................
Specifications Page 6..................
Spec. Gas Heat / High Altitude Page 13...
Blower Data Page 14...................
Electrical Data Page 31.................
I Unit Components Page 35.............
II Placement and Installation Page 48.....
III Start Up Operation Page 48...........
IV Charging Page 50...................
V System Service Checks Page 60.......
VI Maintenance Page 62................
VII Accessories Page 63................
VIII Diagrams Page 69..................

Lennox KGB074S4B Specifications

General

Brand	Lennox
Model	KGB074S4B
Category	Heat Pump
Language	English

Summary

KGB024 through 090 Overview

Electrostatic Discharge (ESD) Precautions

Guidelines for preventing damage from electrostatic discharge during service.

Critical Safety Warnings

Warnings regarding installation, electrical hazards, and handling procedures.

SPECIFICATIONS - DIRECT DRIVE BLOWER

General Data & Cooling Performance

General specifications and cooling performance metrics.

3 Ton & 4 Ton Specifications

Detailed specifications for 3-ton and 4-ton direct drive blower units.

5 Ton Specifications

Detailed specifications for 5-ton direct drive blower units.

SPECIFICATIONS - BELT DRIVE BLOWER

3 Ton, 4 Ton & 5 Ton Specifications

Detailed specifications for belt drive blower units in 3, 4, and 5 tons.

6 Ton Specifications

Detailed specifications for 6-ton belt drive blower units.

6 Ton Two-Speed Specifications

Detailed specifications for 6-ton two-speed belt drive blower units.

7.5 Ton Specifications

Detailed specifications for 7.5-ton belt drive blower units.

SPECIFICATIONS - STANDARD GAS HEAT

Standard Gas Heat Specifications

Heat input, output, temperature rise, and efficiency for standard gas heat.

Low NOx Gas Heat Specifications

Heat input, output, temperature rise, and efficiency for low NOx gas heat.

BLOWER DATA

Direct Drive ECM - 2 Ton | 2.5 Ton

Direct Drive ECM - 3 Ton

Direct Drive ECM - 4 Ton

Direct Drive ECM - 5 Ton

Direct Drive PSC - 3 Ton | 4 Ton

Direct Drive PSC - 5 Ton

Belt Drive (Single Speed) - 3 Ton

Belt Drive (Single Speed) - 4 Ton

Belt Drive (Single Speed) - 5 Ton

Belt Drive (Single and Two-Speed) - 6 Ton (Downflow)

Belt Drive (Single and Two-Speed) - 6 Ton (Horizontal)

Belt Drive (Single and Two-Speed) - 7.5 Ton (Downflow)

Belt Drive (Single and Two-Speed) - 7.5 Ton (Horizontal)

ELECTRICAL DATA

Direct Drive ECM - 2 Ton | 2.5 Ton

Electrical data for 2-ton and 2.5-ton ECM units.

Direct Drive PSC - 3 Ton

Electrical data for 3-ton PSC units.

Direct Drive PSC - 5 Ton

Electrical data for 5-ton PSC units.

Direct Drive ECM - 3 Ton | 4 Ton | 5 Ton

Electrical data for 3, 4, and 5-ton ECM units.

Direct Drive PSC - 4 Ton

Electrical data for 4-ton PSC units.

I-UNIT COMPONENTS

Control Box Components Overview

B-Cooling Components

Safety Switches and Thermostats

Gas Heat Limit and Safety Switches

1-Compressor B1

Description of compressor types and safety warnings.

Combustion Air Inducer and Components

I-UNIT COMPONENTS

Burner Control A3 and Operation

Description of the main burner control and its functions.

B-Determining Unit CFM - Single-Speed, Direct Drive Blowers

Measuring Static Pressure

Procedure for measuring static pressure for CFM determination.

Blower Speed & Location Readings

Adjusting Blower Speeds

Diagrams for field-adjusting blower speeds for direct drive units.

FIELD-ADJUSTABLE BLOWER SPEEDS

Direct Drive 208/230V Speed Adjustment

Diagrams for adjusting blower speeds on 208/230V direct drive units.

Direct Drive 460/575V Speed Adjustment

Diagrams for adjusting blower speeds on 460/575V direct drive units.

C-Determining Unit CFM - Multi-Stage, Direct Drive Blowers

CFM Determination Procedure

Steps for determining CFM for multi-stage direct drive blowers.

D-Determining Unit CFM - Belt Drive Blowers

Procedure for determining CFM for belt drive blowers.

E-Blower Belt Adjustment

Instructions for adjusting blower belt tension and alignment.

BLOWER ASSEMBLY

Figure 11 - Pulley Adjustment & Belt Tension

Diagrams for adjusting pulley and belt tension.

F-Blower Belt Adjustment - M Volt Units

G-Check Belt Tension - Units Not Equipped

D-GAS HEAT COMPONENTS

1-Heat Exchanger Figure 16

Diagram and description of the heat exchanger assembly.

2-Burner Box Assembly (Figure 17)

Diagram and description of the burner box assembly.

III-START UP - OPERATION

A-Preliminary and Seasonal Checks

Checks to perform before starting the unit seasonally or for the first time.

B-Heating Start up

Step-by-step instructions for starting the heating operation.

WARNINGS

Electrical Shock Hazard

Warning about electrical shock hazard during servicing.

Smoke Potential

Danger of Explosion

Warning regarding explosion hazard due to manual lighting attempts.

Gas Valve Operation

Step-by-step procedure for operating the gas valve.

C-Cooling Start up

Operation Sequence

Step-by-step sequence for initiating cooling operation.

Three Phase Scroll Compressor Voltage Phasing

Importance of correct phasing for three-phase scroll compressors.

D-Safety or Emergency Shutdown

Instructions for safely shutting down the unit in an emergency.

IV-CHARGING

Procedure for refrigerant charge and check.

B-Refrigerant Charge and Check - Fin/Tube Coil

Refrigerant Charge Procedure

Procedure for checking refrigerant charge using approach and subcooling methods.

C - Charge Verification - Approach Method

Approach Temperature Comparison

Method for verifying charge using approach temperature.

D - Charge Verification - Subcooling Method

Method for verifying charge using subcooling temperature.

V-SYSTEM SERVICE CHECKS

1-Gas Piping

Guidelines for gas piping installation and testing.

V-SYSTEM SERVICE CHECKS

3-Testing Gas Supply Pressure

Procedure for testing and adjusting gas supply pressure.

7-Flame Sensing

Procedure for checking flame sensing and microamp readings.

4-Check and Adjust Manifold Pressure

Procedure for checking and adjusting manifold pressure.

B-Cooling System Service Checks

5-Proper Gas Flow

VI-MAINTENANCE

ECONOMIZER CONTROLS

Economizer Operation

Outdoor Air Not Suitable

Outdoor Air Suitable

CHART 1

VIII-Wiring Diagrams and Sequence of Operation

KGB024/060 P VOLTAGE UNIT DIAGRAM

Wiring diagram for KGB024/060 P voltage units.

Warnings and Notes

KGB036/090 G, J, M &Y VOLTAGE UNIT DIAGRAM

KGB-074 Two-Stage Units

Sequence of Operation

GAS HEAT FOR KGB024/090 UNITS

First Stage Heat

Second Stage Heat

ELECTRONIC OR ELECTROMECHANICAL THERMOSTAT

Wiring Diagram

ECONOMIZER

A6 ENTHALPY CONTROLLER

Description and settings for the A6 enthalpy controller.

Free Cooling Setpoint

OUTDOOR AIR DAMPER

SEQUENCE OF OPERATION

OPERATION: Occupied Mode

OPERATION: Unoccupied Mode