Lennox HPXA19 User Manual

Page 1
© 2003 Lennox Industries Inc.
Corp. 0302−L2
HPXA19
Service Literature
Revised 07−2006
HPXA19 SERIES UNITS
The HPXA19 is a high efficiency residential split−system
heat pump unit, which features a two−step scroll compres-
sor and R410A refrigerant. HPXA19 units are available in
2, 3 (−036 and −038 models), 4 and 5 ton sizes. The series
includes the HPXA19−038, a 3 ton unit equipped with a vari-
able speed condenser fan motor. The series is designed for
use with an expansion valve only (approved for use with
R410A) 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
subject to change.
IMPORTANT
Operating pressures of this R410A unit are higher
than pressures in R22 units. Always use service
equipment rated for R410A.
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.
IMPORTANT
The Clean Air Act of 1990 bans the intentional vent-
ing of (CFC’s and HFC’s) as of July 1, 1992. Approved
methods of recovery, recycling or reclaiming must
be followed. Fines and/or incarceration my be levied
for noncompliance.
DANGER
Shock Hazard
Remove all power at disconnect be-
fore removing access panel.
HPXA19 units use single-pole con-
tactors. Potential exists for electrical
shock resulting in injury or death.
Line voltage exists at all components
(even when unit is not in operation).
Table of Contents
General 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications / Electrical Data 2. . . . . . . . . . . . . . . . . .
I Application 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
II Unit Components 3. . . . . . . . . . . . . . . . . . . . . . . . . . . .
III Refrigerant System 16. . . . . . . . . . . . . . . . . . . . . . . . . .
IV Charging 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
V Service and Recovery 22. . . . . . . . . . . . . . . . . . . . . . . .
VI Maintenance 22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VII Diagrams and Operating Sequence 23. . . . . . . . . . .

Lennox HPXA19 Specifications

General

Refrigerant	R-410A
Compressor Type	Scroll
Stages	Single-Stage
Smart Technology	No
HSPF Rating	Up to 8.2
Phase	1
Warranty	10-Year Limited Warranty on compressor; 5-Year Limited Warranty on covered components
Heating Capacity (BTU/h)	18, 000 - 56, 000
Cooling Capacity (BTU/h)	18, 000 - 54, 000
Voltage	208/230

Summary

I-Application

II-Unit Components

ELECTROSTATIC DISCHARGE (ESD) Precautions and Procedures

Precautions to avoid electrostatic discharge during installation and service.

A-Two-Stage Scroll Compressor (B1)

Details on the two-stage scroll compressor design and operation.

INTERNAL SOLENOID (L34)

Controls the two-stage operation of the compressor by bypassing ports.

B-Contactor (K1)

Energizes the compressor via a contactor in the control box.

C-Low Pressure Switch (S87)

Auto-reset switch that shuts off compressor on low suction pressure.

D-High Pressure Switch (S4)

Auto-reset switch that shuts off compressor on high liquid line pressure.

E-Capacitor (C12)

Permanent split capacitor for compressor and fan motors.

F-Condenser Fan with Variable Speed Motor(B4)

Variable speed fan motor with electronic control for airflow regulation.

J-Low Ambient Thermostat (S23)

Controls second-stage operation based on ambient temperature.

K-Reversing Valve (L1)

Reverses refrigerant flow for heating and cooling modes.

L-Transformer (T46)

Provides power to the control box components.

M-Solenoid Relay (K195)

Controls the solenoid for second-stage operation.

N-Rectifier Plug (D4)

Converts AC voltage to DC voltage for the unloader solenoid.

O-Discharge Line Thermostat (S5)

Shuts off compressor if discharge line temperature rises too high.

R-Condenser Fan with Variable Speed Motor(B4) (-038 only)

Details on the variable speed fan motor for the -038 unit.

S-Filter Drier

Removes moisture and foreign matter from the refrigerant system.

T-Accumulator (HPXA19-060 only)

Traps and evaporates liquid refrigerant returning to the compressor.

U-Charge Compensator

Collects and stores excess refrigerant in heating mode.

V-Lennox System Operation Monitor (A132)

24V module for troubleshooting system issues with LED indicators.

W-Crankcase Heater (HR1)

Prevents liquid from accumulating in the compressor.

X- Crankcase heater Thermostat (S40)

Controls the crankcase heater based on liquid line temperature.

Y-Defrost System

System for managing defrost cycles based on ice build-up.

Z-Start Capacitor (C7) -024 model only

Provides starting torque for the compressor on 2-ton units.

AA-Potential Relay (K31) -024 model only

Controls the starting circuit and de-energizes the start capacitor.

III-REFRIGERANT SYSTEM

Field refrigerant piping

Details on liquid and vapor lines, including Lennox L15 series line sets.

Service Valves

Information on accessing and operating liquid and vapor line service valves.

IV-CHARGING

A-Leak Testing

Procedures for checking refrigerant lines and the indoor unit for leaks.

B-Evacuating

Process for removing noncondensables and moisture from the system.

C-Charging

Procedures for charging the system with R410A refrigerant.

V-SERVICE AND RECOVERY

Polyol ester (POE) oils

Properties of POE oils and precautions for handling R410A systems.

Moisture Removal

Steps to minimize moisture entering the system during service.

VI-MAINTENANCE

Outdoor Unit

Cleaning and inspection procedures for the outdoor unit components.

Indoor Coil

Cleaning and inspection of the indoor coil and condensate line.

Indoor Unit

Filter replacement, blower checks, and wiring inspection for the indoor unit.

VII-DIAGRAM / OPERATING SEQUENCE

First Stage Cool (low capacity)

Unit operation during low capacity cooling demand.

Second Stage Cool (high capacity)

Unit operation during high capacity cooling demand.

Heating

Unit operation modes for heating based on ambient temperature.

Defrost Mode

How the unit enters and operates during a defrost cycle.