Lennox XC14-042

Page 1
©2007 Lennox Industries Inc.
Corp. 0704−L2
XC14
Service Literature
Revised 07−2008
XC14 SERIES UNITS
The XC14 is a high efficiency residential split−system con-
densing unit, which features a scroll compressor and
R−410A refrigerant. XC14 units are available in sizes rang-
ing from 1 1/2 through 5 tons. The series is designed for use
with an expansion valve or RFC (approved for use with
R−410A) in the indoor unit. This manual is divided into sec-
tions which discuss the major components, refrigerant sys-
tem, charging procedure, maintenance and operation se-
quence.
Information contained in this manual is intended for use by
qualified service technicians only. All specifications are sub-
ject to change.
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 qualified installer or service
agency.
WARNING
Warranty will be voided if covered equipment is re-
moved from original installation site. Warranty will
not cover damage or defect resulting from:
Flood, wind, lightning, or installation and operation
in a corrosive atmosphere (chlorine, fluorine, salt,
recycled waste water, urine, fertilizers, or other dam-
aging chemicals).
DANGER
Shock Hazard
Remove all power at disconnect
before removing access panel.
Single phase XC14 units use single-
pole contactors. Potential
exists for electrical shock resulting
in injury or death.
Line voltage exist at all components
(even when unit is not in operation).
IMPORTANT
Operating pressures of this R−410A unit are higher
than pressures in R−22 units. Always use service
equipment rated for R410A.
TABLE OF CONTENTS
General Page 1. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications / Electrical Data Page 2. . . . . . . . .
I Application Page 4. . . . . . . . . . . . . . . . . . . . . . . . .
II Unit Components Page 4. . . . . . . . . . . . . . . . . .
III Refrigeration System Page 8. . . . . . . . . . . . . . .
IV Charging Page 9. . . . . . . . . . . . . . . . . . . . . . . . .
V Service and Recovery Page 21. . . . . . . . . . . . . .
VI Maintenance Page 21. . . . . . . . . . . . . . . . . . . . . .
VII Wiring and Sequence of Operation Page 22. .

Lennox XC14-042 Specifications

General

Refrigerant	R-410A
Compressor Type	Scroll
Sound Level	74 dB
Voltage	208/230V
Phase	1
Cooling Capacity	42000 BTU/h
Heating Capacity	42000 BTU/hr

Summary

XC14 Series Unit Overview

Installation and Service Risks

Details risks associated with improper installation, adjustment, alteration, or maintenance.

Electrical Shock Hazard Warning

Warns about potential electrical shock from live voltage at all components, even when the unit is not in operation.

R410 A Pressure Operating Warning

Advises users that R-410A units operate at higher pressures and require specific R410A-rated service equipment.

XC14 Unit Specifications Summary

Control Box Electrical Components

Scroll Compressor Description

Filter Drier Requirement

Condenser Fan Motor Service Safety

Includes a critical DANGER warning about disconnecting power before electrical service procedures.

Refrigerant System Plumbing

Refrigerant Charging Procedures

System Leak Testing

Details steps for leak testing the system after line set connections, including using nitrogen and checking for leaks.

R410 A Refrigerant Handling Safety

Warns that R-410A refrigerant can be harmful if inhaled and must be used and recovered responsibly.

System Evacuation Process

Electronic Leak Detection and Pressurization

Deep Vacuum Evacuation Procedure

Details the process for evacuating the system to a specific micron level using a vacuum pump and micron gauge.

R-410 A Refrigerant Charging

Polyol Ester Oil Compatibility Warning

Equipment Damage Warning for Vacuum

Warns against deep vacuum operation using compressors, which can cause damage and void warranty.

Refrigerant Charge Method Determination

RFC Unit Superheat Charging Method

Details the steps and conditions for charging RFC units using the Superheat method, including using tables for comparison.

TXV Unit Approach Charging Method

TXV Unit Subcooling Charging Method

Charging Procedures for Specific XC14 Models

Indoor Coil Airflow Delta-T Check

Explains how to perform an indoor coil airflow check using the Delta-T (DT) method and adjust fan speed.

Delta-T Airflow Adjustment Guide

Guides the user through determining desired DT, measuring actual temperature drop, and adjusting fan speed.

Charge Method Determination Flowchart

TXV Unit Weigh-In Charging Method

TXV Unit Approach Method Charging

TXV Unit Subcooling Method Charging

Fixed Orifice Weigh-In Charging Method

Fixed Orifice Superheat Charging Method

Fixed Orifice Superheat Calculation Guide

System Service and Refrigerant Recovery

Refrigerant System Handling Precautions

Emphasizes keeping the system closed, using R-410A rated recovery machines, and preventing moisture entry.

System Moisture Removal Steps

Wiring Diagrams and Operation Sequence

XC14 Unit Wiring Diagram

XC14 Cooling Operation Sequence