Carrier 38QH User Manual

HEATING & COOLING
38E,Q
Condensing Units and Heat Pumps
Service Manual
38EH,EN,ES,QH,QN,QS
TABLE OF CONTENTS
Page
INTRODUCTION. 1, 2
Models and SEER Ranges. 1
Factory-Installed Options. 2
SAFETY CONSIDERATIONS . . . . .. 3
SERVICE. 3
Cabinet. 3
• REMOVING LOUVERED CASING
• REMOVING FAN ORIFICE
• ELECTRICAL BOX ACCESS
Electrical. 5 - 1 1
• CONTACTORS
• CAPACITORS
• TIME GUARD II
• CRANKCASE HEATER
• PRESSURE SWITCHES
• DEFROST THERMOSTATS ,
• PRINTED-CIRCUIT CONTROL BOARD
• FAN MOTORS
• SERVICE SENTRY CONTROL BOARD
• OUTDOOR THERMOSTATS
Page
Compressor.12-15
• MECHANICAL FAILURES
• ELECTRICAL FAILURES
• SYSTEM CLEAN-UP AFTER BURN-OUT
• COMPRESSOR REMOVAL AND
REPLACEMENT
Refrigeration System . 1 5 - 20
• REFRIGERATION CYCLE
• LEAK DETECTING
• SERVICE VALVES
• CARRIER COMPATIBLE FITTING
• ACCURATER ™ (Bypass Type) COMPONENTS
• REVERSING VALVE
• COIL REMOVAL
• COIL CLEANING
• LIQUID LINE STRAINER
• ACCUMULATOR
• SYSTEM CHARGING (for all approved
combinations)
INTRODUCTION
This Service Manual enables a service technician to similar, however, there are distinct differences. Tables 1
service and repair a family of similar condensing units and 2 help to differentiate these differences,
and heat pumps. Outwardly, many models appear
Models and SEER Ranges
Table 1 — Condensing Units Table 2 — Heat Pumps
MODEL
DIAMETERS SEER*
MODEL
DIAMETERS
SEER* C:O.P.f
(in.)
(Nominal)
(in.)
(Nominal)
(Minimum)
38EH015
22
9.0
38QH015
22
•9.0
2.85
38EH018 22
9.0
38QH018
22
9.0
2.85
38 EH 024
22
9.0
38QH024 30
9.0
2.85
38 EH 030 30
9.0
38QH030 30
9.0 2.85
38 EH 036 30 9.0
38QH036
30
9.0
2.85
38 EH 042 30 9.0
38QH042 30
9.0
2.85
38 EH 048 30 9.0
38QH048
30
9.0
2.85
38 EH 060
30
9.0
38QH060 39
9.0 2.85
38EN015
17
8.0
38QN015
17
8.0
2.55
38EN018
17
8.0
38QN018
17
8.0
2.55
38EN024
17
8.0
38QN024 22
8.0
2.55
38EN030 22
8.0
38QN030
22
8.0 2.55
38EN036
22
8.0
38QN036 30
8.0
2.55
38EN042 30 8.0
38QN042
30
8.0 .
2.55
38EN048 ' 30 8.0
38QN048
30
8.0
2.55
38EN060
30 8.0
38QN060
30
8.0
2.55
38ES018
30 ■
10.0
38QS018
30
10.0
2.85
38ES024
30 10.0
38QS024
30
10.0
2.85
38ES030
30
10.0
38QS030 30
10.0
2.85
38ES036
30
10.0
38QS036
30
10.0
2.85
38ES042
30
10.0
38QS042
30
10.0
2.85
38ES048
30
10.0
38QS048
30
10.0
2.85
38ES060 39
10.0
38QS060
39
10.0 2.85
SEER Seasonal Energy Efficiency Ratio. The higher the number, the fC.O.P. — Coefficient of Performance (heating), determined by dividing
less electrical power required to reach a given capacity. SEER Btu output by power input required to produce this Btu output,
is derived by dividing output energy by input energy.
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 1 |1 |4 |4 PC101 Catalog No. 563-857 Printed in U.S.A. Form38E,Q-1SM Pg 1 11-85 Replaces: New
Tab 3a|5a|2a|5a For replacement items use Carrier Specified Paris.

Carrier 38QH Specifications

General

Brand	Carrier
Model	38QH
Category	Heat Pump
Language	English

Summary

Introduction to Condensing Units and Heat Pumps

Models and SEER Ranges

Lists condensing unit and heat pump models with their SEER ratings.

Factory-Installed Options

Details factory-installed option packages for condensing units and heat pumps.

Safety Considerations

Service - Cabinet and Electrical Access

Cabinet Removal

Instructions for removing the outer casing and accessing internal components.

Electrical Box Access

Guidance on how to access the electrical control box.

Electrical System Components

Contactors

Explains the function and troubleshooting of contactors in the unit.

Capacitors

Details the role of capacitors and how to test them for proper function.

Time Guard II

Explains the solid-state Time Guard device that prevents compressor short cycling.

Crankcase Heater

Describes the crankcase heater's function and troubleshooting.

Pressure Switches

Discusses the function of low and high-pressure switches.

Defrost Thermostats

Explains defrost thermostat operation and testing for heat pumps.

Printed-Circuit Control Board

Details the solid-state defrost control board used in some heat pumps.

Motors and Control Accessories

Fan Motors

Information on fan motor maintenance, lubrication, and troubleshooting.

Service Sentry Control

Describes the Service Sentry control for outdoor unit warnings.

Outdoor Thermostats

Explains the function and testing of outdoor thermostats.

Compressor Mechanical and Electrical Failures

Mechanical Failures

Discusses mechanical issues affecting compressor operation.

Electrical Failures

Covers electrical problems that prevent the compressor motor from running.

Compressor Performance Issues

Covers locked rotor, no pumping, and noise issues.

Compressor Leak Repair

Details how to identify and repair leaks on the compressor.

Compressor Motor Electrical Testing

Winding Circuit Tests

Procedures to test compressor motor windings for open, ground, or short circuits.

System Maintenance After Burn-Out

System Clean-Up After Burn-Out

Procedures for cleaning the system after a compressor motor burn-out.

Compressor Removal and Replacement

Steps for safely removing and installing a replacement compressor.

Refrigeration System Operation

Refrigeration Cycle Explanation

Explains the basic operation of refrigerant flow in cooling and heat pump modes.

Refrigerant System Leak Detection and Service Connections

Leak Detecting Methods

Methods for checking the refrigeration system for refrigerant leaks.

Service Valves and Fittings

Explains service valves and Carrier compatible fittings for system access.

Refrigerant Metering and Reversing Valve

AccuRater™ Components Service

Information on the AccuRater piston, retainer, and their service.

Reversing Valve Troubleshooting

Describes the reversing valve's function and troubleshooting in heat pumps.

Outdoor Coil Service

Coil Removal Procedure

Step-by-step instructions for removing the outdoor coil assembly.

Coil Cleaning and Strainer Maintenance

Coil Cleaning Procedures

Procedures for cleaning the outdoor coil to maintain efficiency.

Liquid Line Strainer Service

Explains the function of the liquid line strainer and its replacement.

Accumulator Service and System Charging

Accumulator Maintenance

Details the accumulator's function, potential issues, and replacement.

System Charging Procedures

Guidelines for correctly charging the refrigeration system.