Lennox CBA25UHV - User Manual

©2021 Lennox Industries Inc.
Dallas, Texas, USA
Page 1
THIS MANUAL MUST BE LEFT WITH THE
HOMEOWNER FOR FUTURE REFERENCE
WARNING
Improper installation, adjustment, alteration, service
or maintenance can cause property damage, personal
injury or loss of life. Installation and service must be
performed by a licensed professional HVAC installer or
equivalent, service agency, or the gas supplier.
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.
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.
INSTALLATION
INSTRUCTIONS
MULTI-POSITION AIR HANDLERS
507775-02
2/2021
Merit
®
Series
CBA25UHV Air Handler Units
Shipping and Packing List
Package 1 of 1 contains:
1 – Assembled air handler unit factory-equipped for upow
or horizontal air discharge application (includes upow
and horizontal drain pans and preinstalled air lter).
Check the air handler for shipping damage; if found, im-
mediately contact the last carrier. Check the unit rating
plate to conrm that delivered unit matches order.
General Information
The CBA25UHV series air handler with all-aluminum
coil is designed for indoor installation only. As shipped,
the unit is ready for installation in either upow or horizon-
tal right-hand air discharge applications. Horizontal drain
pan may be repositioned in the eld to allow installation
in the horizontal left-hand air discharge position. Various
accessories are available and listed in the CBA25UHV
Product Specication bulletin (EHB) for ordering.
This instruction is intended as a general guide and does
not supersede local or national codes in any way. Consult
authorities having jurisdiction before installation.
IMPORTANT: Special procedures are required for clean-
ing the all-aluminum coil in this unit. See page 22 in this
instruction for information.
Table of Contents
CBA25UHV Unit Dimensions – Upow – Inches (mm) ..2
Requirements ................................................................3
Installation Clearances ..................................................3
Installation .....................................................................4
Condensate Drain...........................................................7
Duct System and Filters ...............................................8
Brazing Refrigerant Lines .............................................. 9
Sealing the Unit ...........................................................12
Electrical Connections ................................................. 12
BDC3 Blower Control ..................................................16
Adjusting the Blower Speed ........................................16
Check-out Procedures .................................................21
Maintenance ................................................................21
Repairing or Replacing Cabinet Insulation ..................21
Professional Maintenance ...........................................22
Use of Air Handler During Construction .......................22

Lennox CBA25UHV Specifications

General

Type	Air Handler
Model	CBA25UHV
Brand	Lennox
Efficiency	Up to 16 SEER
Refrigerant	R-410A
Nominal Voltage	208/230V
Width	21 inches
Compatibility	Compatible with Lennox outdoor units
Nominal Cooling Capacity	1.5 to 5 tons
Motor Type	PSC or ECM
Airflow Range	Up to 2000 CFM
Motor	Variable Speed Motor

Summary

Installation Overview

Shipping and Packing List

Lists contents of the package and initial inspection.

General Information

Provides a general overview of the unit and installation.

Installation Requirements and Safety

Unit Weight and Handling Safety

Warns about injury from improper handling of heavy units.

Refrigerant System and Code Compliance

Covers refrigerant control, system matching, and code adherence.

Flammable Vapor and Condensation Hazards

Alerts to flammable vapors and condensation issues in unconditioned spaces.

Installation Clearance Requirements

Details clearances for accessibility, service, and combustible materials.

Installation Configuration Options

Upflow Application Setup

Instructions for configuring the unit for upflow air discharge.

Horizontal Application Notes

General notes for horizontal installations.

Right-Hand Discharge Configuration

Specific steps for right-hand horizontal air discharge.

Horizontal Discharge Modifications

Left-Hand Air Discharge Field Modifications

Field modifications required for left-hand horizontal air discharge.

Downflow Installation

Downflow Application Kit and Installation

Information on ordering kits and specific installation requirements for downflow.

Condensate Drain System Installation

Main and Overflow Drain Plumbing

Proper installation of primary and secondary drain lines, traps, and sloping.

Secondary Drain Pan Requirements

When a secondary drain pan is required and its specifications.

Drain and Duct System Setup

Condensate Drain Line Installation and Testing

Detailed steps for connecting drain lines and testing.

Duct System Sizing and Filter Installation

Guidelines for supply/return duct connections and filter sizing.

Ductwork and Refrigerant Line Connections

Duct System Installation Details

Connecting supply air duct and return air flanges.

Brazing Refrigerant Lines Safety and Procedure

Safety and procedural instructions for brazing refrigerant lines.

Refrigerant Line Installation Best Practices

Refrigerant Line Routing and Protection

Guidance on routing, insulating, and protecting refrigerant lines from damage.

Brazing Process and Connections

Brazing Connection Procedure with Nitrogen Purge

Step-by-step guide for making brazed connections with nitrogen purge.

Unit Sealing and Electrical Wiring

Cabinet Sealing for Moisture Control

Instructions for sealing the cabinet to prevent moisture ingress.

Electrical Connection Safety and Guidelines

Safety warnings and guidelines for making electrical connections.

Electrical Connections and Voltage Conversion

Electrical Wiring Routing and Grounding

Further details on routing wires and grounding.

208 Volt Conversion Procedure

Procedure to convert the unit from 240VAC to 208VAC.

Electrical Wiring Diagrams

Electric Heat Wiring Diagram

Illustrates the wiring for electric heat components and controls.

Low Voltage Thermostat Wiring

Thermostat Wiring Configurations

Diagrams showing thermostat wiring for various system types.

Blower Control and Speed Configuration

BDC3 Blower Control Features

Explanation of the BDC3 control features and jumpers.

Adjusting Blower Speed Settings

How to select and adjust blower speed settings using jumpers.

Blower Performance Data Tables

CBA25 UHV-018 Blower Performance

Performance table for CBA25UHV-018 unit, listing CFM at various settings.

CBA25 UHV-024 Blower Performance

Performance table for CBA25UHV-024 unit, listing CFM at various settings.

Blower Performance Data Tables

CBA25 UHV-030 Blower Performance

Performance table for CBA25UHV-030 unit, listing CFM at various settings.

CBA25 UHV-036 Blower Performance

Performance table for CBA25UHV-036 unit, listing CFM at various settings.

Blower Data and System Operation

CBA25 UHV-042 Blower Performance

Performance table for CBA25UHV-042 unit, listing CFM at various settings.

Thermostat and Outdoor Unit Operating Sequences

Table detailing system response to thermostat and outdoor unit conditions.

System Operation and Control Sequences

Two-Stage Outdoor Unit Operating Sequences

Sequences for two-stage systems including cooling and heat.

Heat and Delay Jumper Functions

Explains the function of heat and delay jumpers for fan operation.

System Checks and Maintenance

Pre-Start-Up and Operational Checks

Pre-start-up checks and operational testing for system verification.

Routine Maintenance and Filter Care

Routine maintenance tasks including filter inspection and replacement.

Insulation Repair and Construction Use

Repairing Damaged Cabinet Insulation

Instructions for repairing or replacing damaged cabinet insulation.

Air Handler Use During Construction

Guidelines for using the unit during building construction.

Professional Coil Cleaning and Maintenance

Recommendations for professional cleaning and maintenance of the coil.

Installation Verification

Upflow Configuration Start-up Checklist

Checklist for verifying installation and performance in upflow mode.

Performance Verification

Horizontal Configuration Start-up Checklist

Checklist for verifying installation and performance in horizontal mode.