Lennox CBX25UH Series User Manual

Page 1
CBX25UH
Service Literature
Corp. 1241-L9
December 2012
INSTALLATION AND SERVICE PROCEDURE
Revised August, 2018
CBX25UH Series
WARNING
Improper installation, adjustment, alteration, service or
maintenance can cause personal injury, loss of life, or
damage to property.
Installation and service must be performed by a licensed
professional installer (or equivalent) or a service agency.
CAUTION
Physical contact with metal edges and corners while
applying excessive force or rapid motion can result in
personal injury. Be aware of, and use caution when
working near these areas during installation or while
servicing this equipment.
IMPORTANT
The Clean Air Act of 1990 bans the intentional venting of
refrigerant (CFCs, HCFCs and HFCs) as of July 1, 1992.
Approved methods of recovery, recycling or reclaiming
must be followed. Fines and/or incarceration may be
levied for noncompliance.
Table of Contents
Unit Dimensions 2............................
Specifications / Electrical Data 3................
Model Number Information 4...................
Blower Data 4................................
Application 6.................................
Unit Components 6............................
Optional ECB25 Electric Heat 7.................
Configuration Modification 10...................
Electrical Connections 16......................
Wiring Diagrams 17...........................
Start-Up Operations 19........................
Sequence of Operations 20....................
Performance Checklists 21.....................
The CBX25UH are high-efficiency air handler. Several models
are available in sizes ranging from 1‐1/2 through 5-tons. The
CBX25UH is designed for HFC-410A refrigerant.
CBX25UH series units are designed to be matched with either
a13 SEER air conditioner or heat pump, but can be matched
with other air conditioners or heat pumps as noted in the rating
information. See Product Specification bulletin.
This air handler is designed for indoor installation only. As
shipped, the unit is ready for installation in either upflow or
horizontal left-hand. Field modifications are required for
right-hand air discharge applications. Electric heat, down
flow air discharge application kits, air filters and other
various accessories are available and listed in the
CBX25UH Product Specification bulletin for ordering.
All units come with a factory installed check/expansion
valve.
Information contained in this manual is intended for use by
experienced licensed HVAC service technicians only. All
specifications are subject to change. Procedures outlined in
this manual are presented as a recommendation only and do
not supersede or replace local or state codes.

Lennox CBX25UH Series Specifications

General

Refrigerant	R-410A
Stages	Single Stage
Blower Motor Type	ECM
Cabinet Material	Galvanized Steel
Sound Level	Quiet operation
Operating Voltage	208/230V
Unit Dimensions	Varies by model
Unit Weight	Varies by model
Cabinet	Insulated
Coil	Aluminum
Warranty	5-Year Limited Warranty on covered components
Cooling Capacity	1.5 to 5 Tons
SEER Rating	Up to 16 SEER

Summary

Installation and Safety Precautions

Safety Warnings and Cautions

Key safety warnings including danger, caution, and important regulatory notices.

Specifications and Electrical Data

General Data and Connections

Tonnage, line sizes, and coil data for different models.

Blower and Electrical Specs

Motor specs, filter size, voltage, and electrical requirements.

Blower Configuration and Adjustment

Changing Blower Speed

Step-by-step guide to adjust blower speed for optimal airflow.

ESD Safety Precautions

Precautions to protect electronic components from ESD during service.

Blower Performance

Blower Performance Table

CFM data for different models across static pressure ranges.

Unit Components and Application

Application Matching

Electric Heat Installation

Heat Section Installation Procedure

Detailed steps for installing electric heat sections into the air handler.

Heat Installation Safety

Critical safety warnings for electrical shock and physical injury during heat installation.

Electrical Connections

Power Supply Wiring

Connecting field power supply to circuit breakers or terminal blocks.

Configuration and Mounting

Upflow Application Setup

Horizontal Application Setup

Blower Speed for Electric Heat

Condensate Drainage System

Drain Line Requirements and Traps

Requirements for overflow, secondary drain lines, and traps.

Sloping the Drain Pan

Installation Procedures

Condensate Drain Installation

Steps for installing the condensate drain system.

Refrigerant Line Connection

TXV Relocation and Unit Sealing

Relocating TXV Bulb

Sealing Unit Entry Points

Ensuring an airtight seal around wires, tubing, and lines to prevent moisture issues.

Electrical Connections and Voltage

Electrical Safety Warnings

Critical warnings regarding electric shock and proper wiring practices.

208 Volt Conversion

Low Voltage Wiring Diagrams

Cooling-Only Wiring

Heat-Only Wiring

Cooling with Electric Heat Wiring

Heat Pump Wiring Diagrams

Heat Pump with Electric Heat Wiring

Start-Up Procedures

Pre-Start-Up Checks

Comprehensive checklist before energizing the unit for operation.

Sequence of Operation

Operation Checks

Procedures to verify blower, cooling, and heating system functionality.

Performance Checklists (Upflow)

Duct System and Control Checks

Voltage, Drain, Static, and Temperature Checks

Performance Checklists (Horizontal)

Duct System and Control Checks (Horizontal)

Voltage, Drain, Static, and Temperature Checks (Horizontal)