TechnicalOrder_Refrigerator_5_20_24.pdf

TO 13B5-9-1

TECHNICAL MANUAL

OPERATION AND

MAINTENANCE INSTRUCTIONS

WITH ILLUSTRATED PARTS BREAKDOWN

REFRIGERATOR

PN CD90059

NSN 4110-01-433-0294

TECA Thermoelectric Cooling America Corporation

DAAB07-92-Z-B506

This manual supersedes TO 13B5-9-1 dated 7 June 2015.

DISCLOSURE NOTICE - This information is furnished upon the condition that it will not be released to another nation without the specific authority of the Department of the Air Force of the United States, that it will be used for military purposes only, that individual or corporate rights originating in the information, whether patented or not, will be respected, that the recipient will report promptly to the United States, any known or suspected compromise, and that the information will be provided substantially the same degree of security afforded it by the Department of Defense of the United States. Also, regardless of any other markings on the document, it will not be downgraded or declassified without written approval of the originating United States agency.

DISTRIBUTION STATEMENT B - Distribution authorized to U.S. Government Agencies only (Administrative or Operational Use) (1 October 1996). Other requests for this document shall be referred to 406 SCMS/GUEE, Robins AFB, GA 31098. Questions concerning technical content shall be referred to AFMC AFLCMC/WNZEA.

WARNING - This document contains technical data whose export is restricted by the Arms Export Control Act (Title 22, U.S.C., Sec 2751, et seq.) or the Export Administration Act of 1979, as amended, Title 50, U.S.C., App. 2401, et seq. Violations of these export laws are subject to severe criminal penalties. Disseminate in accordance with provisions of DoD Directive 5230.25.

HANDLING AND DESTRUCTION NOTICE - Comply with distribution statement and destroy by any method that will prevent disclosure of contents or reconstruction of the document.

Published Under Authority of the Secretary of the Air Force

31 AUGUST 2020

Dates of issue for original and changed pages are:

Original. . . . . . . .0 . . . . . 31 August 2020

TOTAL NUMBER OF PAGES IN THIS PUBLICATION IS 62, CONSISTING OF THE FOLLOWING:

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Title A i - vii viii Blank 1-1 - 1-2 2-1 2-2 Blank 3-1 - 3-2 4-1 - 4-2 5-1 - 5-21 5-22 Blank 6-1 6-2 Blank 7-1 - 7-10 7-11 Blank 7-12 - 7-16

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TO 13B5-9-1

LIST OF EFFECTIVE PAGES

INSERT LATEST CHANGED PAGES. DESTROY SUPERSEDED PAGES.

NOTE The portion of the text affected by the changes is indicated by a vertical line in the outer margins of the page. Changes to illustrations are indicated by shaded or screened areas, or by miniature pointing hands.

* Zero in this column indicates an original page.

A USAF

TABLE OF CONTENTS

Chapter Page

LIST OF ILLUSTRATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv

LIST OF TABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v

SAFETY SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii

1 GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

1.1 GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

1.2 DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

1.3 CAPABILITIES AND FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

1.4 LEADING PARTICULARS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

2 SPECIAL TOOLS AND TEST EQUIPMENT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

2.1 GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

2.2 CONSUMABLE MATERIALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

3 PREPARATION FOR USE AND SHIPMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

3.1 PREPARATION FOR USE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

3.2 PREPARATION FOR SHIPMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

3.3 PREPARATION FOR STORAGE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

4 OPERATION INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

4.1 THEORY OF OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

4.1.1 Cross-Section Circuitry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

4.2 OPERATING INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

5 MAINTENANCE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

5.1 GENERAL REQUIREMENTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

5.2 OPERATIONAL CHECKOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

5.3 CLEANING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

5.3.1 Routine Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

5.3.2 Annual Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

5.4 INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

5.5 TROUBLESHOOTING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2

5.6 TESTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3

5.6.1 Subassemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4

5.7 TEMPERATURE CONTROLLER CHECKS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4

5.7.1 Temperature Controller Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4

5.7.2 Temperature Control Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4

5.7.3 DC-DC Converter Check. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4

5.7.4 Fan/Temperature Control Power Supply Subassembly Check. . . . . . . . . . . . . . . . . . . . . . . . 5-4

5.7.5 Temperature Controller Sensor Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4

5.8 FAN WIRING CHECKS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5

5.8.1 Fan Voltage Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5

5.8.2 Hot-Side and Cold-Side Fan Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5 i

5.8.3 Checks When All Fans Fail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5

5.9 Thermoelectric Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6

5.9.1 Input Power Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6

5.9.2 Drive Signal Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6

5.9.3 Thermoelectric Subassembly Voltage/Resistance Check . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6

5.10 FAULT ISOLATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7

5.10.1 Sensor Fault . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7

5.10.2 Nonvolatile Memory Error. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7

5.11 REPAIR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8

5.12 GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8

5.13 Door/Hinge Assembly Removal/Reversal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8

5.14 TEMPERATURE CONTROLLER REPLACEMENT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11

5.14.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11

5.14.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11

5.15 REAR PANEL REPLACEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11

5.15.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11

5.15.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12

5.16 POWER INPUT CONNECTOR REPLACEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15

5.16.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15

5.16.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15

5.17 REFRIGERATOR RACK ASSEMBLY REPLACEMENT . . . . . . . . . . . . . . . . . . . . . . . . . 5-15

5.17.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15

5.17.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15

5.18 Refrigerator Heat Sink Subassembly Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16

5.18.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16

5.18.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17

5.19 FAN REPLACEMENT, HOT SIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17

5.19.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17

5.19.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20

5.20 FAN REPLACEMENT, COLD SIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20

5.20.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20

5.20.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20

5.21 THREADED HELI-COIL REPAIR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21

5.22 THREADED INSERT REMOVAL/REPLACEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21

6 DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

6.1 GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

6.2 DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

7 ILLUSTRATED PARTS BREAKDOWN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

SECTION I INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

7.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

7.2 MODELS COVERED. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

7.3 FINDING PART NUMBERS, ILLUSTRATION, DESCRIPTION . . . . . . . . . . . . . . . . . . . . 7-1

7.4 SIMILAR ASSEMBLIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

7.5 SHEET NUMBER EXPLANATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

7.6 USABLE ON CODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

7.7 SOURCE, MAINTENANCE, AND RECOVERABILITY (SMR) CODES . . . . . . . . . . . . . . 7-1

7.8 PARTS STANDARDIZATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2

7.9 MANUFACTURER’S LIST. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2

7.10 MAINTENANCE PARTS LIST (MPL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2

7.10.1 Figure and Index Number Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2

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7.10.2 Part Number Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2

7.10.2.1 Commercial Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2

7.10.2.2 Parts Not Illustrated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2

7.10.2.3 Markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2

7.10.2.4 Government Furnished Equipment (GFE) and Contractor Furnished Equipment (CFE) Covered by Separate Manuals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2

7.10.3 CAGE Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2

7.10.4 Description Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2

7.10.4.1 Indentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3

7.10.5 Units Per Assembly Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3

7.10.6 Usable on Code Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3

7.10.7 Source, Maintenance, and Recoverability (SMR) Code Column. . . . . . . . . . . . . . . . . . . . . . 7-3

7.11 NUMERICAL INDEX (NI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3

7.11.1 Part Number Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3

7.11.2 Figure and Index Number Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3

7.12 REFERENCE DESIGNATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3

7.12.1 Reference Designator Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3

7.12.2 Figure and Index Number Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4

SECTION II MAINTENANCE PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7

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LIST OF ILLUSTRATIONS

Number PageTitle

1-1 CD90059 Refrigerator Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 4-1 Cross-Section of a Typical Thermoelectric Cooler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2 4-2 Temperature Controller Setting Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2 5-1 Temperature Controller Error Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8 5-2 Refrigerator Door/Hinge Assembly Reversal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10 5-3 Temperature Controller Removal/Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-13 5-4 Rear Panel/Rack Assembly Removal/Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14 5-5 Heat Sink Subassembly Removal/Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18 5-6 Refrigerator Rack Panel Assembly Removal/Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19 7-1 Refrigerator Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7 7-2 Refrigerator Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8 7-3 Insulation Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-10 7-4 Rack Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-12 FO-1 Refrigerator Rack Panel Wring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . FP-1 FO-2 Refrigerator Rack Panel Wring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . FP-3

LIST OF TABLES

Number PageTitle

1-1 Leading Particulars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 2-1 Special Tools and Test Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 2-2 Consumable Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 5-1 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2 5-2 Wire Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3 iv

INTRODUCTION

1 PURPOSE.

This manual contains operation and maintenance procedures and an Illustrated Parts Breakdown of the electric Refrigerator PN CD90059 manufactured by Thermoelectric Cooling America Corporation (TECA), Chicago, IL 60622.

2 SCOPE.

This manual contains operation and maintenance procedures and an illustrated parts breakdown for the refrigerator, part number CD90059. See Figure 1-1.

3 SYMBOLS.

- A dash (-) before an index number denotes a part which is not illustrated.

* An asterisk (*) flush right of the part number denotes a marking that is to be requisitioned in accordance with DODI 5330.03_AFI 33-395.

# A number sign (#) flush right of a part number indicates that detail parts are listed in a separate manual.

F The letter “F” before the figure number means “follows” and is used when an assembly or part has not been assigned an index number, and the figure and index number of the preceding part has been used.

4 ABBREVIATIONS.

All abbreviations used in this manual are in accordance with ASME Y14.38, Abbreviations and Acronyms for Use on Drawings and Related Documents.

AC Alternating Current AF Air Force AFTO Air Force Technical Order ALT Alternate AP Attaching Parts AR As Required ASSY Assembly CAGE Commercial and Government Entity CFE Contractor Furnished Equipment DAPS Document Automation and Production Ser-vice DC Direct Current °F degrees Fahrenheit DoD Department of Defense GFE Government Furnished Equipment HCI Hardness Critical Items Hz Hertz I&S Interchangeability and Substitution IPB Illustrated Parts Breakdown MPL Maintenance Parts List NHA Next Higher Assembly NI Numerical Index PN Part Number RDI Reference Designator Index REF Reference SMR Source, Maintenance, and Recoverability v

TO Technical Order UOC Usable on Code VAC Volts Alternating Current VDC Volts Direct Current

5 RELATED PUBLICATIONS.

The following publications contain information in support of this technical manual.

List of Related Publications

Number Title ASME Y14.38 Abbreviations and Acronyms for Use on Drawings and Related Documents DODI 5330.03_AFI 33-395 Document Automation and Production Service (DAPS) TO 00-5-1-WA-1 Air Force Technical Order System TO 00-25-195-WA-1 Source, Maintenance, and Recoverability Coding of Air Force Weapons, Systems, and

Equipment TO 00-25-234-WA-1 General Shop Practice Requirements for the Repair, Maintenance, and Test of Electri-cal Equipment

6 RECORD OF APPLICABLE TIME COMPLIANCE TECHNICAL ORDERS (TCTOS).

List of Time Compliance Technical Orders

TCTO

Number

TCTO

Title

TCTO

Date

None

7 HARDNESS CRITICAL ITEMS (HCI).

The HCI symbol ( ) establishes special requirements limiting changes and substitutions and that the specific parts listed must be used to ensure hardness is not degraded.

If included, items with nuclear survivability requirements are marked with the HCI symbol ( ). All changes to, or proposed substitutions of, HCIs must be approved by the acquiring activity.

8 ELECTROSTATIC DISCHARGE SENSITIVE (ESDS) ITEMS.

All ESDS parts shall be handled in accordance with the ESDS device handling procedures in TO 00-25-234-

WA-1.

If included, items containing ESDS parts are marked with the ESDS symbol ( ).

9 IMPROVEMENT REPORTS.

Recommended changes to this manual shall be submitted in accordance with TO 00-5-1.

vi

SAFETY SUMMARY

1 GENERAL SAFETY INSTRUCTIONS.

This manual describes physical and/or chemical processes which may cause injury or death to personnel, or damage to equipment, if not properly followed. This safety summary includes general safety precautions and instructions that must be understood and applied during operation and maintenance to ensure personnel safety and protection of equipment. Prior to performing any specific task, the WARNINGs, CAUTIONs, and NOTEs included in that task shall be reviewed and under-stood.

2 WARNINGS, CAUTIONS, AND NOTES.

WARNINGs and CAUTIONs are used in this manual to highlight operating or maintenance procedures, practices, condi-tions, or statements which are considered essential to protection of personnel (WARNING) or equipment (CAUTION).

WARNINGs and CAUTIONs immediately precede the step or procedure to which they apply. WARNINGs and CAUTIONs consist of four parts: heading (WARNING, CAUTION, or icon), a statement of the hazard, minimum precautions, and possible results if disregarded. NOTEs are used in this manual to highlight operating or maintenance procedures, practices, conditions, or statements which are not essential to protection of personnel or equipment. NOTEs may precede or follow the step or procedure, depending upon the information to be highlighted. The headings used and their definitions are as follows:

Highlights an essential operating or maintenance procedure, practice, condition, statement, etc., which if not strictly observed, could result in injury to, or death of, personnel or long term health hazards.

Highlights an essential operating or maintenance procedure, practice, condition, statement, etc., which if not strictly observed, could result in damage to, or destruction of, equipment or loss of mission effectiveness.

NOTE

Highlights an essential operating or maintenance procedure, condition, or statement.

3 SAFETY PRECAUTIONS.

• Do not attempt internal service or adjustment with power applied unless another person capable of rendering aid and resuscitation is present. Personnel working with or near dangerous voltage shall be trained in modern methods of resuscitation. Information and training sources may be obtained from the director of base medical services.

• Keep cleaners in approved safety containers and in minimum quantities. Some cleaners/chemicals may have an effect on skin, eyes, and respiratory tract. Observe manufacturer’s WARNING label; Material Safety Data Sheets (MSDS) instructions for proper handling, storage, and disposal; and current safety directives. Use only in autho-rized areas. Discard soiled cleaning cloths into safety cans.

• When cleaners and primers are being applied, use approved explosion-proof lights, blowers, and other equipment.

Ensure that fire fighting equipment is readily available and in working order.

• Wear protective clothing/equipment (gloves, apron, eye protection, etc.) approved for the materials, procedures, and tools being used. Contact supervisor for guidance. If necessary, the bioenvironmental engineer of the base safety office should be contacted for guidance.

vii/(viii blank)

CHAPTER 1

GENERAL INFORMATION

1.1 GENERAL.

The CD90059 refrigerator is a food service galley refrigerator designed for use in an aircraft. A solid-state, adjustable temperature controller located at the front of the unit senses the refrigerator’s internal temperature and directs temperature cycling. Solid-state thermoelectric modules cool the internal air by recirculating it through cold-side heat exchangers. Each cooling assembly module consists of thermoelectric parts, heat exchangers, and fans. Modules are assembled onto a central rack panel located at the rear of the unit. Heat dissipates at the refrigerator rear as it is blown through hot-side heat exchangers.

1.2 DESCRIPTION.

The refrigerator has the capacity for five open-grid, wire basket-type drawers (17.75 inches wide x 24.5 inches deep x 6.0 inches high). The service door, which is reversible for right- or left-hand operation, is opened by means of a paddle latch. A redundant safety retaining latch prevents inadvertent opening. The door gasket contains magnetic strips throughout which seal tightly with magnetic strips in the door facing of the refrigerator The refrigerator consists of two stainless steel boxes separated by polyurethane foam insulation. A solid-state, programmable temperature controller, located at the front of the unit, adjusts the temperature cycle. The refrigerator should maintain a temperature of 38±5 degrees Fahrenheit (°F) at a maximum temperature behind the refrigerator of 110 °F. The period of operation required to maintain this range is directly related to cabin temperature and the temperature both inside and behind the refrigerator.

1.3 CAPABILITIES AND FEATURES.

Each refrigerator will hold five wire baskets, which together have the capacity to hold approximately 106 meals.

1.4 LEADING PARTICULARS.

The leading particulars of the refrigerator are listed in Table 1-1.

Table 1-1. Leading Particulars

Item Characteristics Height 35.8 inches Width 22.2 inches Depth 37.8 inches Weight (empty) 237 pounds Power requirement 115/208 Volts Alternating Current (VAC), 3 phase, 400

Hertz (Hz) Power consumption 1350 watts, 4 Amperes Maximum ambient operating temperature 110 °F Temperature range 38±5 °F

1-1

Figure 1-1. CD90059 Refrigerator Assembly

1-2

CHAPTER 2

SPECIAL TOOLS AND TEST EQUIPMENT

2.1 GENERAL.

For a list of special tools and test equipment needed to repair and maintain the refrigerator, refer to Table 2-1.

2.2 CONSUMABLE MATERIALS.

For a list of consumables, refer to Table 2-2.

Table 2-1. Special Tools and Test Equipment

Tool/Equipment Number Cage Figure Num-ber

Nomenclature Use and Application

M81969/14-03 77820 5-4 Insert and removal tool Removal/installation of power input connector.

6041 5-4 Hotmelt glue gun Secure insulating foam to cold side of rack panel.

M-77/89536 N/A Multimeter Check voltage/resistance.

AN/PSM37 or equiva-lent 4-2 Thermometer, refrigerator Check inside temperature of refrigerator.

AA170 84256 N/A Manual placing tool Install inserts when original inserts become loose.

AA271-420 84256 N/A

Conversion kit Convert manual placing tool for use with inserts of vari-ous sizes.

1227-6 01556 N/A Extraction Tool Remove inserts.

Table 2-2. Consumable Materials

Nomenclature Specification Part Number/Cage Hotmelt glue Local purchase Solder, 60/40 resin core J-STD-006 Silicone adhesive MIL-A-46146B Isopropyl alcohol, technical TT-I-735 HeliCoil, 1/4-20 NASM8846 5401-4/01556 Master thread repair kit AAT-312-420 75834 Desiccant MIL-D-3464E

2-1/(2-2 blank)

CHAPTER 3

PREPARATION FOR USE AND SHIPMENT

3.1 PREPARATION FOR USE.

a. Inspect packaging for signs of damage during transit.

b. Remove nails from base flap of carton. Lift carton off of refrigerator. Save shipping carton for future use.

c. Remove four capscrews (two in front, two in rear), four nuts, and four flatwashers from the skid. Retain skids, capscrews, flatwashers, and nuts for shipping.

d. Install two stainless steel straps (Figure 1-1, 7), Part Number (PN) 8946610-1, with 12 screws (8), PN MS240693-S96.

e. Apply power to refrigerator. Once power is applied, the refrigerator is operational. There is no on/off switch.

NOTE

If the internal temperature is lower than the set point, the unit will not run.

f. The refrigerator’s inner temperature and the setting of the temperature controller dictate the on-off state of the unit.

3.2 PREPARATION FOR SHIPMENT.

a. Wipe refrigerator inside and baskets with a clean, dry cloth.

The refrigerator weighs approximately 230 pounds. A minimum of two personnel are required to lift the refrig-erator. Team lifting or material handling equipment (if available) is required to lift and move the refrigerator.

Failure to comply may result in injury to personnel and damage to the equipment.

NOTE

Remove and retain stainless steel straps for installation.

b. If original shipping carton is available, place refrigerator on skids. Attach refrigerator to skids using four capscrews (two in front and rear on each skid), four nuts, and four flatwashers. Do not reuse the holes previously used.

c. Cover refrigerator with carton and nail base flap to carton, making sure not to reuse original nail holes.

d. If original carton is not available, pack unit for shipment in accordance with MIL-STD-2073-1.

3.3 PREPARATION FOR STORAGE.

If a refrigerator is to be stored indefinitely, perform the following procedures to assure that the interior will stay free of moisture.

a. Carefully clean the interior surfaces. Refer to Paragraph 5.3. Remove any corrosion, soil, grease, fingerprints, and alkali or acid residues.

b. Thoroughly dry surfaces to remove moisture and any residual cleaning solutions.

3-1

c. Immediately before boxing for storage, add to the enclosure nine units of bagged, activated desiccant in accordance with MIL-D-3464. Tie or tape bags to the interior of the refrigerator.

3-2

CHAPTER 4

OPERATION INSTRUCTIONS

4.1 THEORY OF OPERATION.

See Figure 4-1. The CD90059 refrigerator makes use of a thermoelectric cooling system that refrigerates without the freezer, condenser, and compressor that conventional refrigeration employs. Instead of a refrigerant, which in conventional refrig-eration boils, changes to vapor, and absorbs heat, the thermoelectric cooler uses two dissimilar conductors. Electrons absorb heat as they pass from one semiconductor (the n-type) to another (p-type). A heat sink discharges the accumulated heat energy from the system. Thermoelectric cooling, then, refrigerates without use of mechanical devices and without refriger-ant.

4.1.1 Cross-Section Circuitry. A complete circuit of two dissimilar thermoelectric conductors is called a couple. Couples similar to that shown in Figure 4-1 are normally combined in a module sandwiched between a hot-side and a cold-side heat sink. The CD90059 refrigerator has six such modules, each of which has a hot-side and cold-side fan. The thermoelectric subassemblies are grouped into sets of two, each set with its own independent power supply. The power supplies take the incoming Alternating Current (AC) voltage, rectify and filter it, and apply the voltage to the thermoelectrics via control relays. Each fan has one subassembly that converts incoming AC to Direct Current (DC) voltage and a second subassembly that converts the DC power into 24 Volts Direct Current (VDC) and supplies this power to the fans via a control relay.

4.2 OPERATING INSTRUCTIONS.

a. Apply power to the refrigerator.

NOTE

If the refrigerator is packed with frozen meals, the inside temperature will be lower than the temperature range preset on the controller. The temperature controller sensor will not indicate cooling, and the refrigerator may not appear to be working.

b. The temperature controller, located on the top front of the unit, is preset to 38±5 degrees Fahrenheit °F. (See Figure 4-2.) If the internal temperature is higher than the setpoint, the temperature controller will energize, read the internal temperature, and signal for cooling.

NOTE

Do not store meals or snacks in refrigerator with the wire baskets removed. Storing meals or snacks with basket removed can cause overfilling, which could impede air circulation due to improper clearances. Do not overfill the wire baskets. Leave three inches of dead space at the back of baskets two, three, and four so that fans can circulate the air.

c. To determine the setpoint temperature, push the * button on the temperature controller. A Light Emitting Diode (LED) display will indicate the preprogrammed setpoint in °F.

d. Adjust the temperature to approximately 38±5 °F. Hold the * button while pressing the up-arrow button.

NOTE

Use Fluke 51/52 or equivalent to measure the temperature inside the refrigerator.

e. Allow the refrigerator to cycle several times. Ensure that the inside temperature falls to 38±5 °F.

f. Once the inside temperature remains at 38±5 °F, lower the temperature by holding the * button and pressing the down-arrow button.

4-1

Figure 4-1. Cross-Section of a Typical Thermoelectric Cooler

Figure 4-2. Temperature Controller Setting Adjustment

4-2

CHAPTER 5

MAINTENANCE INSTRUCTIONS

5.1 GENERAL REQUIREMENTS.

This chapter contains operational checkout, inspection, preventive maintenance, and troubleshooting procedures for main-taining the refrigerator. Standard shop tools and equipment are required. For a list of tools and test equipment, see Table 2-1.

5.2 OPERATIONAL CHECKOUT.

a. Apply power to the refrigerator.

b. Verify that the Light Emitting Diode (LED) display on the temperature controller, located on the front of the unit, illuminates.

c. Allow refrigerator to cycle several times. Assure that internal temperature of 38±5 °F is maintained.

5.3 CLEANING.

5.3.1 Routine Cleaning.

NOTE

Hose washing, immersion, pressure washing, and soaking are not recommended for cleaning the refrigerator.

a. Wipe all work surfaces, including wire basket surfaces, with a mild solution of dish washing soap and water.

b. Wipe soap off surfaces with clean, damp cloth.

c. If necessary, clean door seal using mild soap and a small, soft-bristle brush.

5.3.2 Annual Cleaning. Perform once per year or as service conditions dictate.

Use of compressed air can create an environment of propellent foreign particles. Air pressure shall be reduced to less than 30 Pounds per Square Inch (PSI) and used with effective chip guarding and personal protective equip-ment. Failure to comply can cause serious injury to personnel.

a. With power disconnected and rear panel removed, note six fans behind rear grills. Using a hand-operated, compressed-air nozzle, blow directly onto the fans with compressed 30 PSI air.

b. Move air nozzle back and forth across fans to force out dust and debris. Ensure that debris is blown away from heat rejection fins.

5.4 INSPECTION.

a. Check refrigerator interior and exterior surfaces for cleanliness.

b. Check hinge for loose or missing hardware and freedom of movement.

c. Check door handle and latch for proper operation and for loose or missing hardware.

d. Check door seal for cleanliness, deterioration, and security.

5-1

e. Check wire baskets for dents, distortion, corrosion, and cleanliness.

f. Check wire basket guides for distortion, corrosion, and loose or missing rivets.

g. Check temperature controller for security and proper operation.

h. Check wiring for deterioration and evidence of overheating.

i. Check power input connector for loose, bent, or missing pins.

5.5 TROUBLESHOOTING.

Table 5-1, Troubleshooting, lists symptoms, their probable cause, and the corrective action for correcting malfunction.

Troubleshooting should be performed in a standard shop environment using a 115/208 Volts Alternating Current (VAC), 3 phase, 400 Hertz (Hz) power source with ohmmeters and voltmeters to simultaneously measure the current and voltage of each phase. Refer to the tools and test equipment listed in Table 2-1.

Table 5-1. Troubleshooting

Symptom Probable Cause Corrective Action Controller display is not illuminated

Refrigerator power input Ensure power is applied to refrigerator.

Bad connection to controller Check power to controller. Ensure connection is not faulty.

Bad wiring to controller Perform temperature controller check, Paragraph

5.7.1.

Blown fuse on temperature control sub-assembly

Replace 1/2 Amperes fuse.

Temperature control/Direct Current DC-DC subassembly wiring faulty

Perform checks Paragraph 5.7.2 and Paragraph

5.7.3. If necessary, replace wiring.

Faulty temperature control power sup-ply wiring/fuse

Perform check Paragraph 5.7.4. If necessary, re-place fuse, surge suppressors.

Faulty rectifier/wiring If required after performing Paragraph 5.7.4, re-place rectifier/wiring.

Faulty power resistor/wiring If required after performing Paragraph 5.7.4, re-place resistor/wiring

Incorrect temperature dis-play

Controller error Check controller. Perform sensor check, Paragraph

5.7.5. Replace controller.

Faulty wiring Check wiring. See Paragraph 5.7.5. Ensure sound connection; replace wiring.

Faulty sensor Perform check in Paragraph 5.7.5. If sensor is faulty, replace controller.

One fan fails to operate Obstruction to fan impeller Remove power and remove obstruction. Restart unit and check fan operation for signs of imbal-ance.

Fan failure Measure voltage at the fan. Perform check Para-graph 5.8.1. If connection is good and 24 Volts Direct Current (VDC) is present, replace fan.

Voltage not present Perform fan voltage check, Paragraph 5.8.1. Ensure terminal strip jumpers are present.

Faulty wiring Perform fan voltage check, Paragraph 5.8.1. Re-place faulty wires.

Two fans (hot and cold-side subassembly fans) fail

Obstruction to fan impeller Remove power, remove obstruction, and restart unit. Observe fan operation for signs of imbalance or damage. If fan does not restart, replace fan.

Fan voltage Perform checks Paragraph 5.8.1 and Paragraph

5.8.2. Replace distribution leads.

5-2

Table 5-1. Troubleshooting - Continued

Symptom Probable Cause Corrective Action All fans fail Power to fan relay Perform checks Paragraph 5.8.3. Replace wiring.

Terminal jumpers/wiring Perform check Paragraph 5.8.3. Replace jumpers or wiring.

Controller relay Perform check Paragraph 5.8.3. Replace controller.

Subassembly relay Perform check Paragraph 5.8.3. Replace relay.

One thermoelectric set fails

Power supply Check input power. Perform check Paragraph 5.9.1.

Blown fuse/wiring short circuits Check fuse. Perform Paragraph 5.9.1.

Hot-side fan obstruction/failure Check hot-side fan for obstruction. Perform fan voltage check, Paragraph 5.9.1.

Drive signal Perform drive signal check, Paragraph 5.9.2. If necessary, replace wiring from relay.

Voltage Perform voltage check, Paragraph 5.9.2. If neces-sary, replace relay.

Resistance bad on thermoelectric leads Perform resistance checks Paragraph 5.9.3. If resis-tance is bad, replace subassembly.

Thermoelectric subassembly intercon-nect wiring

Check/replace wiring, Paragraph 5.9.3.

Surge suppressors on terminal strip Replace surge suppressors.

Voltage Perform voltage check, Paragraph 5.9.3.

Fuse to subassembly Check fuse, Paragraph 5.9.3. Replace fuse.

All thermoelectric sets fail Temperature controller Perform temperature controller checks, Paragraph 5.7.

Fan Perform fan checks, Paragraph 5.8.

Refrigerator inner temperature too cool Check to see if refrigerator temperature is greater than the set point of the controller.

Drive distribution wiring Check wiring. Replace faulty wiring. If temperature controller calls for cooling and fans are operating, the fan/temperature control power supply, DC-DC converter, and temperature control subassemblies are operating. Also, drive signal is getting to double-row terminal strip on temperature control subassem-bly. If drive distribution wiring is not faulty, treat problem as three separate thermoelectric set failures.

Perform troubleshooting for individual thermoelec-tric sets.

5.6 TESTING.

Input power for the refrigerator comes from the rear by way of a mating connector. The connecting wires consist of the following:

Table 5-2. Wire Connections

Pin Color Use/Destination A Black/white Hot side B Black/white Hot side C Black/white Hot side D White Common F Green Ground

5-3

5.6.1 Subassemblies. The three thermoelectric subassemblies, as viewed from the rear of the refrigerator, form a three column, two row grid. A set of two subassemblies makes up each column. Although thermally each subassembly performs the same function, the subassemblies differ electrically in their components.

5.6.1.1 In each set one subassembly contains both the power supply components and the relay that powers the thermo-electric. These thermoelectric power supply subassemblies comprise the top row of the grid. One interconnection between these subassemblies routes the incoming VAC through thermostats located on the hot-side heat sink of each subassembly.

These thermostats will open at approximately 212 °F, protecting the thermoelectric in case of hot-side fan failure, hot-side airflow obstruction, or any other situation which might cause inordinately high temperature in the hot-side heat sink. Another interconnection also provides DC voltage to both subassemblies in each set. The thermoelectrics for each pair are wired in series.

5.6.1.2 The subassemblies on the bottom row of the three-column, two-row grid perform different functions. One contains the rectifier that filters and rectifies 115 VAC to 125 VDC. A relay on the second subassembly receives the voltage, converts it to 24 VDC, and sends it to the fans and to the third subassembly, which powers the temperature controller.

5.6.1.3 The testing procedures in the following paragraphs consist of voltage checks to the six subassemblies, the fans, and the temperature controller. See Figure 5-4, FO-1, and FO-2.

5.7 TEMPERATURE CONTROLLER CHECKS.

NOTE

• Perform these checks with power applied.

• Tag and mark all wires before removing any components.

5.7.1 Temperature Controller Check. (See Figure 5-3.) With temperature controller cover removed, check input voltage at terminals seven and eight of the temperature controller. Voltage should be 24 VDC. (Actual input could be 8-35 VDC.) If no voltage is present, check connection and the 1/2 ampere fuse on the temperature control subassembly (Figure 5-4, 11).

5.7.2 Temperature Control Check. (See Figure 5-6.) On the temperature controller subassembly (2) check for 24 VDC across fuse output and terminal three of four-place, double-row terminal strip (5). If there is no voltage, go to Paragraph 5.7.3.

5.7.3 DC-DC Converter Check. See Figure 5-6.

a. Check for 24 VDC on the output of the DC-DC converter (3). If 24 VDC exists, check for same voltage across negative ( - ) output and terminal two of the D2D12 relay (7) on the DC-DC converter. If this voltage is present, look for a defect in the subassembly interconnect wiring on the cold side. Replace wiring if necessary.

b. Verify power input to the DC-DC converter (8) (across + in and - in). Voltage should be 110-140 VDC.

5.7.4 Fan/Temperature Control Power Supply Subassembly Check. See Figure 5-6.

a. Check for 110-140 VDC across terminals 5 and 9 of the VI-AIM-C1 AC/DC module. Result – if voltage is not present, proceed to Step b. If voltage is present, troubleshoot for a defect in the subassembly interconnect wiring on the cold side.

b. Check for 120 VAC on input terminals of the VI-AIM-C1 AC/DC module, terminal 1 and 4. Result – if voltage is present, replace VI-AIM-C1 AC/DC module. If voltage is not present, proceed to Step c.

c. Check the 7 amp fuse for continuity. If the fuse checks good and there is voltage at the fuse but no voltage at terminals 1 and 4, troubleshoot for a defect in the wiring between the 7 amp fuse and terminal 1, and between terminal 4 and ground.

5.7.5 Temperature Controller Sensor Check. See Figure 5-4. If previous checks show no fault in the wiring but there is an incorrect display, the problem lies in the sensor, sensor wires, or the controller itself.

5-4

a. Check controller.

(1) Remove power from temperature controller and remove connector.

(2) Disconnect leads to terminals one and two of the temperature controller and replace with 100 ohm resistor.

Display should read 32 °F. If it does not, replace the controller.

b. Check wiring.

(1) Ensure wiring is secure at the rear of the controller.

(2) Check five-pin connector (12) on the temperature controller (11).

c. Check sensor and sensor wiring. With power removed, measure the resistance across the black and red leads to the five-pin connector (12). The sensor is a 100 ohm, two-wire resistance temperature detector. The resistance should roughly correspond to the following linear equation:

sensor ohms = 100 ohms +

0.214 ohms (°F – 32)

°F Example (sensor at 77 °F):

109.6 ohms = 100 ohms +

0.214 ohms (77 °F – 32)

°F

5.8 FAN WIRING CHECKS.

(See Figure 5-6, FO-1, and FO-2.) The six fans require 24 VDC voltage and are powered from the same source. The fan/temperature controller power supply subassembly (4) rectifies and filters 115 VAC and routes the resulting DC voltage to the cold side of the DC-DC converter subassembly (3), through the subassembly, to the input of the DC-DC converter. There it is converted to 24 VDC and routed to the temperature controller. A solid-state relay routes the voltage back to the DC-DC converter subassembly (3), which distributes it to all the subassemblies. The cold-side fans are wired to terminals six and eight of terminal strip B. The hot-side fans are wired to terminals seven and five of terminal strip B by way of the cable which runs from the hot to the cold side of the subassemblies.

NOTE

Perform all fan voltage checks with power applied and the temperature controller set so that the refrigerator is cooling.

5.8.1 Fan Voltage Check.

a. Check for 24 VDC at the fan. If connections are in good condition and 24 VDC is present but fan does not operate, replace fan.

b. If no voltage is present and wiring is in good condition, check for 24 VDC at terminals six and eight of terminal strip A on the cold side. If there is a single-fan failure, 24 VDC will be present unless the terminal strip jumpers have been removed.

c. If the jumpers are present and 24 VDC exists at the terminal strip but not at the fan, wiring between the terminal strip and the fan may be defective.

5.8.2 Hot-Side and Cold-Side Fan Checks. To check failure of two subassembly fans, perform checks described in a.

If no voltage is present at terminal strip A, the fan voltage distribution leads are faulty.

5.8.3 Checks When All Fans Fail.

a. Ensure proper power input to refrigerator is 115/208 VDC.

5-5

b. Verify that the drive signal to the fan relay is present. 24 VDC should exist across terminals three and four of the DC relay.

c. If voltage is not present, check for 24 VDC across terminals two and three on the terminal block of the temperature controller subassembly (2). If voltage is present, check the terminal jumpers on the strip to see that they are in place.

Verify that the wiring from the terminal strip to the relay is in good condition.

d. If voltage is not present in Paragraph 5.8.3, Step c, perform temperature controller check, Paragraph 5.7.1.

e. Check the rear connector of the temperature controller to see if the white jumper across terminals five and eight is present and functioning. Also check across terminals five and six for 24 VDC. If 24 VDC is present, the internal relay of the controller is not functioning. Replace controller and verify fan performance.

f. If 24 VDC is present when Paragraph 5.8.3, Step b is performed, measure voltage across relay terminals one and two.

If 24 VDC is measured, the relay is bad and needs to be replaced. If no voltage is present, perform checks described in Paragraph 5.8, Steps b through d.

5.9 THERMOELECTRIC CHECKS.

See Figure 5-6, FO-1, and FO-2.

5.9.1 Input Power Check.

NOTE

To determine if a set is not functioning, touch the hot-side heat sink. It will feel warm if the subassembly is not operating.

a. On the thermoelectric power supply subassembly (1), confirm 115 VAC across the common (white) lead to the rectifier

(14) and the input (black/white) to the fuse (15).

b. Check 5 Amperes fuse (15) on subassembly. If fuse is blown, replace fuse and restart unit. Observe operation through several on-off cycles. If fuse blows again, inspect for wiring short circuits (Paragraph 5.8.3, Steps a and b).

5.9.2 Drive Signal Check.

NOTE

Each thermoelectric set has two hot-side safety thermostats, one for each subassembly, which will interrupt power to the power supply if the hot-side heat sink overheats. The thermostat will reset upon cool-down and allow set to operate again. Overheating is most often caused by malfunctioning hot-side fans and obstructed hot-side airflow.

a. Verify that the drive signal to the subassembly relay is present.