Lennox CBX40UHV Series

Page 1
2018 Lennox Industries Inc.
Corp. 0906-L2
CBX40UHV
Service Literature
Revised August, 2018
INSTALLATION AND SERVICE
PROCEDURE
CBX40UHV (HFC-410A) SERIES UNITS (Communicating)
NOTICE
A thermostat is not included and must be ordered
separately.
D A Lennox communicating thermostat must be used in
communicating applications
(CBX40UHV-XXX-230-6-02 and later).
D In non-communicating applications, the Lennox
ComfortSense
®
7500 thermostat may be used, as well
as other non-communicating thermostats.
In all cases, setup is critical to ensure proper system
operation.
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.
TABLE OF CONTENTS
Model Number Identification 2.......................
Specifications / Electrical Data 2.....................
Blower Performance 3..............................
Parts Arrangement 3...............................
Application 9......................................
Unit Components 9.................................
Field Wiring 13....................................
Air Handler Control Button, Display and Jumpers 17....
Variable Speed ECM Blower Motor 20................
Optional ECB40 Electric Heat 25.....................
Optional Humidity Control 25........................
Unit Sequence of Operations 33.....................
Unit Status and Alarm Codes 35.....................
Application Configuration Modifications 38.............
Start-Up Operation 41..............................
Operating Characteristics 41........................
Maintenance 42....................................
Configuring Unit Flow Charts 43.....................
Unit Diagram 52...................................
Electric Heat Diagrams and Sequence of
Operations 53.....................................
CBX40UHV series units are designed to be matched with
Lennox two‐stage or single‐stage HFC-410A air conditioner
units and heat pumps. Several models are available in sizes
ranging from 2 through 5 tons. All units are equipped with
factory installed HFC-410A check and expansion valve for
cooling or heat pump applications.
This air handler is compatible with the ComfortSense® 7500
non-communicating thermostat and non-communicating
outdoor units. In addition, this unit has the enhanced
capability of communicating with a communicating
thermostat and compatible outdoor units using the Lennox
RSBus protocols.
Optional ECB40 electric heat is available in several kW
sizes, and can be field installed in the cabinets.
This document provides service information on the
following model builds:
1. Non-communicating version (CBX40UHV-XXX-
230-6-01)
2. Communicating version (CBX40UHV-XXX-
230-6-02) or later.

Lennox CBX40UHV Series Specifications

General

Brand	Lennox
Model	CBX40UHV Series
Category	Air Handlers
Language	English

Summary

CBX40 UHV Series Air Handler Installation and Service

Model Number Identification and Specifications

Details on unit model identification, specifications, and electrical data.

Blower Performance Data

Tables detailing blower performance (CFM and Watts) for various models and settings.

Parts Arrangement and Unit Components

Explains the physical parts of the unit and their arrangement within the cabinet.

Control System Overview

Information on the Air Handler Control, sensors, and transformer.

Field Wiring Diagrams

Guides for connecting the unit to thermostats and outdoor units, including diagrams.

Thermostat Connections

Explains thermostat terminal functions for different system configurations.

Air Handler Control Operation and Settings

Covers blower speed control, delay profiles, button functions, and jumper settings.

Jumper and Link Guide

Detailed guide for setting jumpers and links on the air handler control board.

Variable Speed ECM Blower Motor

Explains the function, internal operation, and start-up of the ECM blower motor.

Blower Motor Troubleshooting

Procedures for diagnosing issues with the indoor blower motor and its control module.

Optional Electric Heat Components and Data

Information on electric heat components, ratings, diagrams, and sequences.

Electric Heat Data Tables

Tables detailing electrical data for single and three-phase electric heat options.

Humidity Control and Thermostat Operation

Explains humidity control functions of the ComfortSense 7000 thermostat and operation modes.

Unit Sequence of Operations

Details system responses to thermostat demands for cooling, heating, and dehumidification.

Unit Status, Alarm Codes, and Error Codes

Explains system status codes, alarm codes, and error code recall procedures.

Application Configuration Modifications

Instructions for modifying unit configuration for different installation types.

Start-Up, Operation, and Maintenance

Covers start-up checks, operation, maintenance tasks, and safety precautions.

Unit Diagrams and Electric Heat Schematics

Includes unit diagrams, wiring schematics, and detailed electric heat circuit diagrams.