Carrier 38QN 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 38QN Specifications

General

Brand	Carrier
Model	38QN
Category	Heat Pump
Language	English

Summary

Safety Considerations

Electrical Components

Contactors

Capacitors and Start Assist

Hard-Start Capacitors and PTC Devices

Temporary Capacitance Boost

Time Guard II

Pressure Switches

Defrost Thermostats

Troubleshooting Defrost Control

Service Sentry Control Board

Compressor Overview

Mechanical Compressor Failures

Compressor Failure Diagnosis

Locked Rotor

Troubleshooting locked rotor condition in compressors.

Runs, Doesn't Pump

Diagnosing compressor issues where it runs but doesn't pump.

Electrical Failures

Discusses electrical compressor failures.

Noisy Compressor

Motor Winding Electrical Tests

Ground Circuit Test

Testing for shorts to ground in motor windings.

Short Circuit Test

System Clean-Up After Burn-Out

Compressor Removal and Replacement

Refrigeration Cycle

Leak Detecting

Service Valves

Carrier Compatible Fitting

Reversing Valve

Accumulator

System Charging