Lennox LGH300S - User Manual

Page 1
UNIT INFORMATIONUNIT INFORMATION
Service Literature
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.
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.
WARNING
Improper installation, adjustment, alteration,
service or maintenance can cause property damage,
personal injury or loss of life. Installation and service

agency.
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 disconnect
switch(es). Unit may have multiple power
supplies.
Table of Contents
Options / Accessories . . . . . . . . . . . . . . . . . . . . . Page 2

Blower Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 15
Electrical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 18
I-Unit Components . . . . . . . . . . . . . . . . . . . . . . . Page 23
II-Placement and Installation . . . . . . . . . . . . . . . Page 46
III-Charging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 46

V-System Service Checks . . . . . . . . . . . . . . . . . Page 83
VI-Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . Page 86
VII-Accessories. . . . . . . . . . . . . . . . . . . . . . . . . . Page 87
The LGH156H, 180H, 180U, 210H, 240H, 240U, 300S

units (CTO) with a wide selection of factory installed op-
tions.
LGH156H is available in 260,000 Btuh or 360,000 Btuh
(76.2 or 105.5 kW) and has the option for single stage

LGH180H, 180U, 210H, 240H, 240U, 300S and 300U
units are available in 260,000, 360,000 or 480,00 Btuh
(76.2, 105.5 or 140.7 kW) heating inputs.
The LGH180H/U and 210H also has an optional single

Gas heat sections are designed with aluminized steel tube
heat exchangers with stainless steel as an option.
Cooling capacities range from 13 to 25 tons (45.7 to 88
kW). LGH156H, 180H, and 210H utilize three compres-
sors while LGH180U, 240H, 240U, 300S and 300U utilize
four compressors.
Units are designed for R410A refrigerant. See unit name-
plate. Operating pressures and pressure switch settings
       
equipment must be rated for R410A.
Multi-Stage Air Volume MSAV
®
blower option is available.
The VFD-driven blower will operate at lower speeds when
demand is low and increase to higher speeds when de-
mand is high.
Variable speed VAV system is available as an option which
enables supply duct static measurement to control blow-
er CFM and discharge air temperature to control cooling
stages.
󰀨-
ent energy management thermostat control systems with
-
tions connect to the unit through Smartwire connectors.
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.
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.
LGH SERIES
13 to 25 ton
45.7 to 88 kW
Copr 1013-L2
Revised 05/2020
LGH156H through 300U

Lennox LGH300S Specifications

General

Brand	Lennox
Model	LGH300S
Category	Air Conditioner
Language	English

Summary

UNIT INFORMATION

Safety Precautions

Crucial safety precautions including lock-out/tag-out, moving parts, and electrical hazards.

OPTIONS; ACCESSORIES - ECONOMIZER, OUTDOOR AIR

Economizer Options

Details available economizer system options.

UNIT SPECIFICATIONS

General Data

Cooling Performance

Details cooling capacity, airflow, power, EER, and IEER ratings.

Refrigerant Charge

Lists refrigerant type and charge amounts per circuit.

Outdoor Coils and Fans

Indoor Coils

Indoor Blower and Drive Selection

Information on blower motor output and drive kit numbers.

Filters and Electrical Characteristics

Specifies filter type, size, and electrical characteristics.

Gas Heat Specifications

Details usage, derate, and input rates for gas heating.

Blower CFM Specifications

Lists minimum and maximum CFM values for blower speeds.

ELECTRICAL DATA

13 Ton High Efficiency Electrical Data

Details electrical data for 13-ton high-efficiency units.

15 Ton High Efficiency Electrical Data

Details electrical data for 15-ton high-efficiency units.

17.5 Ton High Efficiency Electrical Data

Details electrical data for 17.5-ton high-efficiency units.

20 Ton High Efficiency Electrical Data

Details electrical data for 20-ton high-efficiency units.

25 Ton Standard Efficiency Electrical Data

Details electrical data for 25-ton standard-efficiency units.

15 Ton Ultra High Efficiency Electrical Data

Details electrical data for 15-ton ultra-high-efficiency units.

20 Ton Ultra High Efficiency Electrical Data

Details electrical data for 20-ton ultra-high-efficiency units.

25 Ton Ultra High Efficiency Electrical Data

Details electrical data for 25-ton ultra-high-efficiency units.

Electrical Accessories - Disconnects

CONTROL BOX COMPONENTS

VFD Controller (GP board) A133 (Staged-Blower units)

Controls and monitors the VFD A96.

REFRIGERANT CIRCUITS

156 H, 180 H, 210 H Plumbing, Compressor and Refrigerant Circuits Detail (Figure 7)

240 H, 300 S, 300 U Plumbing, Compressor and Refrigerant Circuits Detail (Figure 8)

REFRIGERANT CIRCUITS

180 U, 240 U, 300 U Refrigerant Circuits

180 U, 240 U, 300 U Compressor Detail

Diagram showing compressor and switch details.

B-Cooling Components

Compressors B1, B2, B13 (all units) B20 (180 U, 240, 300)

Details compressor types and quantities per model.

High Pressure Switches S4, S7, S28, S96

Explains high-pressure switches and their function.

Low Ambient Switches S11, S84, S85 (all units) S94 (240, 300)

Describes low ambient switches for operation at low temperatures.

B-Cooling Components

Freezestats S49, S50, S53 (all units) and S95 (240, 300)

Details freezestats to prevent evaporator coil icing.

OPERATION; ADJUSTMENT

Blower Operation

Determining Unit Air Volume

Procedure to adjust motor pulley for desired CFM.

DRIVE COMPONENTS

Table 6 - Drive Components (Adjustable;Fixed Sheave)

Table 7 - Drive Components (Belts;Split Bushing)

D-GAS HEAT COMPONENTS

Normal Ignition Sequence - Timings Nominal (Figure 16)

Burner Ignition Control A3, A12

Details the UTEC ignition controls and LED codes.

Retrials - Ignition Attempt Sequence - Timings Nominal (Figure 17)

Ignition Control Timing (Figure 18)

B-Cooling System Service Checks

Procedures for checking cooling system charge using approach method.

Oil Check Injection Procedure 180 U, 240 U, 300 U

D-GAS HEAT COMPONENTS

Heat Exchanger (Figure 19)

Illustrates the heat exchanger assembly and its function.

II-PLACEMENT AND INSTALLATION

General Installation Guidelines

III-CHARGING

Aluminum Coils - Do not exceed nameplate charge

Warnings and procedures for charging aluminum coils.

Charge Unit in Standard Cooling Mode

Important procedure for charging the unit in standard cooling mode.

III-CHARGING

Table 11 - LGH;LCH156 H Normal Operating Pressures - Aluminum Coil

Table of normal operating pressures for cooling circuits.

Table 13 - LGH;LCH156 H VAV Normal Operating Pressures - Aluminum Coil

Table of VAV normal operating pressures for cooling circuits.

Table 14 - LGH;LCH180 H CAV;Staged Normal Operating Pressures - Aluminum Coil

Table of operating pressures for LGH180H CAV/Staged units.

Table 16 - LGH;LCH180 H VAV Normal Operating Pressures - Aluminum Coil

Table of VAV operating pressures for LGH180H units.

Table 18 - LGH;LCH210 H Reheat Normal Operating Pressures - Aluminum Coil

Table of reheat operating pressures for LGH210H units.

Table 20 - LGH;LCH240 H CAV;Staged Reheat Normal Operating Pressures - Aluminum Coil

Table of reheat operating pressures for LGH240H units.

Table 22 - LGH;LCH300 S Normal Operating Pressures - Aluminum Coil

Table of operating pressures for LGH300S units.

LGH;LCH156 CAV;Staged Charging Curve Circuit 1

Charging curve for LGH/LCH156 CAV/Staged Circuit 1.

LGH;LCH156 CAV;Staged Charging Curve Circuit 3

Charging curve for LGH/LCH156 CAV/Staged Circuit 3.

LGH;LCH156 CAV;Staged Reheat Charging Curve Circuit 2

Reheat charging curve for LGH/LCH156 Circuit 2.

LGH;LCH156 VAV Charging Curve Circuit 1

VAV charging curve for LGH/LCH156 Circuit 1.

LGH;LCH156 VAV Charging Curve Circuit 3

VAV charging curve for LGH/LCH156 Circuit 3.

LGH;LCH180 CAV;Staged Charging Curves Circuit 1

Charging curves for LGH/LCH180 CAV/Staged Circuit 1.

LGH;LCH180 CAV;Staged Charging Curves Circuit 3

Charging curves for LGH/LCH180 CAV/Staged Circuit 3.

LGH;LCH180 CAV;Staged Reheat Charging Curves Circuit 1

Reheat charging curves for LGH/LCH180 Circuit 1.

LGH;LCH180 CAV;Staged Reheat Charging Curves Circuit 3

Reheat charging curves for LGH/LCH180 Circuit 3.

LGH;LCH180 VAV Charging Curves Circuit 2

VAV charging curves for LGH/LCH180 Circuit 2.

LGH;LCH210 Charging Curve Circuit 1

LGH;LCH210 Charging Curve Circuit 3

LGH;LCH210 Reheat Charging Curves Circuit 2

LGH;LCH240 CAV;Staged Charging Curves Circuit 1

LGH;LCH240 CAV;Staged Charging Curves Circuit 3

LGH;LCH240 CAV;Staged Reheat Charging Curves Circuit 1

LGH;LCH240 CAV;Staged Reheat Charging Curves Circuit 3

LGH;LCH240 VAV Charging Curves Circuit 1

LGH;LCH240 VAV Charging Curves Circuit 3

LGH;LCH300 S Charging Curve Circuit 1

LGH;LCH300 S Charging Curve Circuit 3

LGH;LCH300 S Reheat Charging Curve Circuit 1

LGH;LCH300 S Reheat Charging Curve Circuit 3

Table 12 - LGH;LCH156 H Reheat Normal Operating Pressures - Aluminum Coil

Table of normal operating pressures for reheat circuits.

Table 15 - LGH;LCH180 H CAV;Staged Reheat Normal Operating Pressures - Aluminum Coil

Table of operating pressures for LGH180H Reheat units.

Table 17 - LGH;LCH210 H Normal Operating Pressures - Aluminum Coil

Table of operating pressures for LGH210H units.

Table 19 - LGH;LCH240 H CAV;Staged Normal Operating Pressures - Aluminum Coil

Table of operating pressures for LGH240H CAV/Staged units.

Table 21 - LGH;LCH240 H VAV Normal Operating Pressures - Aluminum Coil

Table of VAV operating pressures for LGH240H units.

Table 23 - LGH;LCH300 S Reheat Normal Operating Pressures - Aluminum Coil

Table of reheat operating pressures for LGH300S units.

LGH;LCH156 CAV;Staged Charging Curve Circuit 2

Charging curve for LGH/LCH156 CAV/Staged Circuit 2.

LGH;LCH156 CAV;Staged Reheat Charging Curves Circuit 1

Reheat charging curve for LGH/LCH156 Circuit 1.

LGH;LCH156 CAV;Staged Reheat Charging Curve Circuit 3

Reheat charging curve for LGH/LCH156 Circuit 3.

LGH;LCH156 VAV Charging Curve Circuit 2

VAV charging curve for LGH/LCH156 Circuit 2.

LGH;LCH180 CAV;Staged Charging Curves Circuit 2

Charging curves for LGH/LCH180 CAV/Staged Circuit 2.

LGH;LCH180 CAV;Staged Reheat Charging Curves Circuit 2

Reheat charging curves for LGH/LCH180 Circuit 2.

LGH;LCH180 VAV Charging Curves Circuit 1

VAV charging curves for LGH/LCH180 Circuit 1.

LGH;LCH180 VAV Charging Curves Circuit 3

VAV charging curves for LGH/LCH180 Circuit 3.

LGH;LCH210 Charging Curve Circuit 2

LGH;LCH210 Reheat Charging Curves Circuit 1

LGH;LCH210 Reheat Charging Curves Circuit 3

LGH;LCH240 CAV;Staged Charging Curves Circuit 2

LGH;LCH240 CAV;Staged Charging Curves Circuit 4

LGH;LCH240 CAV;Staged Reheat Charging Curves Circuit 2

LGH;LCH240 CAV;Staged Reheat Charging Curves Circuit 4

LGH;LCH240 VAV Charging Curves Circuit 2

LGH;LCH240 VAV Charging Curves Circuit 4

LGH;LCH300 S Charging Curve Circuit 2

LGH;LCH300 S Charging Curve Circuit 4

LGH;LCH300 S Reheat Charging Curve Circuit 2

LGH;LCH300 S Reheat Charging Curve Circuit 4

C-Charge Verification - Approach Method AHRI Testing (Fin;Tube Coil)

Approach Temperature Comparison

Compares liquid temperature to outdoor ambient for charge verification.

Table 37 - Approach Temperatures - Fin;Tube Coil

IV-STARTUP - OPERATION

Preliminary and Seasonal Checks

Cooling Startup

Procedure for starting the unit in cooling mode.

C-Heating Startup

FOR YOUR SAFETY READ BEFORE LIGHTING

Critical safety warnings before lighting the appliance.

Placing Furnace In Operation

Step-by-step guide for placing the furnace into operation.

Safety or Emergency Shutdown

Instructions for performing a safety or emergency shutdown.

V- SYSTEMS SERVICE CHECKS

A-Heating System Service Checks

Procedures for checking gas piping and supply pressure.

Gas Piping

Testing Gas Piping

Testing Gas Supply Pressure

Check and Adjust Manifold Pressure

ECONOMIZER SEQUENCE OF OPERATION

Economizer Control Modes

IX-Staged-Blower

A-Design Specifications

B-Set Maximum CFM

C-Enter Design Specifications Into M2 and M3 Controller

D-Set Damper Minimum Position

OPERATION

A-Two-Stage TStat; 3- and 4-Compressor Units

B-Three-Stage TStat, 3 and 4 Compressor Units AND Zone Sensor (4 Clg. Stages), 3-Compressor Units

C-Zone Sensor (4 Clg. Stages), 4-Compressor Units

1-Economizer With Outdoor Air Suitable

2-No Economizer or Outdoor Air Not Suitable

X-VAV System

A-Start-Up

SUPPLY AIR VARIABLE FREQUENCY DRIVE

B-Unit Operation

C-Supply Air VFD Bypass (Optional)

XI-Wiring Diagrams and Sequence of Operation

LGH156 UNIT DIAGRAM

LGH180 UNIT DIAGRAM

LGH180 UNIT DIAGRAM

LGH210 UNIT DIAGRAM

LGH210 UNIT DIAGRAM

LGH240;300 UNIT DIAGRAM

LGH240;300 UNIT DIAGRAM

Sequence of Operation LGH156;300

1 ST STAGE COOLING (BOTH COMPRESSORS B1 AND B2 ARE ENERGIZED)

Sequence for first stage cooling operation.

2 ND STAGE COOLING (B13 IN 156 H-210 H AND BOTH B13 AND B20 IN 240 H AND 300 S ARE ENERGIZED)

Sequence for second stage cooling operation.

Sequence of Operation LGH180 U, 240 U, 300 U

POWER

BLOWER OPERATION (OCP INPUT MUST BE ON)

ECONOMIZER OPERATION

1 ST STAGE COOLING

Sequence for first stage cooling operation.

2 ND STAGE COOLING

Sequence for second stage cooling operation.