1996 Us Army Facilities Engineering Electrical Exterior Facilities 201p

8/13/2019 1996 Us Army Facilities Engineering Electrical Exterior Facilities 201p

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REPRODUCTION AUTHORIZATION/RESTRICTIONS

This manual has been prepared by and for the Government and,except to the extent indicated below, is public property and not sub-

ject to copyright.

Copyrighted material included in the manual has been used with theknowledge and permission of the proprietors and is acknowledged as

such at point of use. Anyone wishing to make further use of anycopyrighted material, by itself and apart from this text, should seeknecessary permission directly from the proprietors.

Reprints or republication of this manual should include a credit sub-stantially as follows: J oint Departments of the Army, the Navy andthe Air Force, TM 5-864/NAVFAC MO-200/AFJ MAN32-1082.

If the reprint or republication includes copyrighted material, the

credit should also state: Anyone wishing to make further use ofcopyrighted material, by itself and apart from this text, should seeknecessary permission directly from the proprietor.

Tables 13-l and 16-1 are reprinted from table 2 of IEEE Std 18-1992and table 11.1 of IEEE Std 519-1992 respectively.

Copyright 1993 by the Institute of Electrical and Electronics Engi-neers, Inc. The IEEE disclaims any responsibility or liability resulting

from the placement and use in this publication. Information is re-printed with the permission of the IEEE.

WWW.SURVIVALEBOOKS.COM


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TM 5-684/NAVFACMO-200/AFJMAN32-1082

HEADQUARTERS

TECHNICAL MANUAL No. 5-684

DEPARTMENTS OF THE ARMY,

NAVYPUBLICATION NAVFAC MO-200 THE NAVY , AND THE AIR FORCE

AIR FORCEJ OINT MANUAL No. AFJ MAN 32-1082 WASHINGTON , D.C.29 N ovember 1996

ELECTRICAL EXTERIOR FACILITIES

CHAPTER 1. INTRODUCTION

SECTION I-PRIMARY CONSIDERATIONSPurpose and scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Application of codes and publications. .....................................................

Standardsofmaintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Maintenance responsibilities. .............................................................

Maintenance records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Priority and scheduling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION II-SAFETYMinimizinghazards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Qualification of electric workers. ..........................................................

Certification of electric workers ...........................................................

Publicsafety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Personnelsafety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Live-linemaintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION III-AVOIDING PROBLEMSOperating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Detecting potential trouble ...............................................................Electrical connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

CHAPTER 2. INSPECTION AND TESTS

SECTION I-PERFORMANCEDetermining equipment condition .........................................................

Reasons for inspections and tests .........................................................

Associated test guidance and records. .....................................................

SECTION I I -REQUIREMENTSElectric workers, instruments, and reportsFrequencyofinspection.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

CHAPTER 3. TRANSMISSION AND DISTRIBUTION SUBSTATIONS

SECTION I-GOVERNING CONSIDERATIONSTypeofsubstationscovered . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Electrical system relationships. ...........................................................Substation safetyconcern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Substation security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Periodic inspections of substations ........................................................

Visual inspections of substations ..........................................................

Infrared inspections of substations ........................................................

SECTION II-STRUCTURE MAINTENANCEImportanceofmaintenance..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Galvanized steelstructure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Painted steel structures.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Aluminumstructures.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Wood structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Concrete for structure foundations ........................................................

Structure connections and joints ..........................................................

SECTION III-SUBSTATION YARDS

Provisionofyards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Fences for yards.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Warningsignsatyards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Substationyards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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SECTION IV-INSULATORSFunction ofinsulators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Testsofinsulators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Inspection and repair of insulators........................................................Cleaningofinsulators . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . .

SECTION V-BUS STRUCTURESDefinitionofbus structures . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . .

Maintenance of bus structures . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . ..Cleaningofbus structures . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . .

Testingofbus structures . . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . .

SECTION VI-INSTRUMENT TRANSFORMERSDefinitions of instrument transformers....................................................Short-circuiting dangers. .................................................................Maintenanceofinstrumenttransformers.. . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . .

Tests of instrument transformers . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . .

SECTION VII-BUSHINGSDefinition ofbushing . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . .

Type of bushings covered . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . .

Maintenanceofbushings . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . .

Bushingpowerfactortests . . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . .

Bushing insulation resistance test.........................................................

CHAPTER 4. OVERHEAD DISTRIBUTION

SECTION I-ASSOCIATED OVERHEAD DISTRIBUTION GUIDANCERelevant overhead distribution guidance...................................................General construction guidance . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. .

SECTION II-DEFINING VOLTAGE NOMENCLATUREVoltage terminology . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . .Voltagelevelclassification . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . .

Voltagedeliveryusage . . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . .

Voltage origination point ..................................................................Voltage terminology usage in this manual .................................................

SECTION III-TYPES OF MAINTENANCE

Componentlinemaintenance . . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . . .. .Other types of line maintenance . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . . .

SECTION IV-WOOD POLESL ifespanofwoodpoles . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . .

Supplementary data on wood poles. .......................................................

Wood pole record keeping and inspections .................................................Wood pole maintenance crew instructions..................................................Wood pole spot inspection procedures......................................................

Wood pole-by-pole inspection procedure. ...................................................Determination of wood pole adequacy .....................................................Woodpolereplacement . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . .

Woodpolereinforcement . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . .

SECTION V-CROSSARMS, BRACES, AND PLATFORMS

Polecrossarms . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . .Pole braces . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . .

Pole platforms . . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . ..

SECTION VI-MAINTENANCE WOOD PRESERVATION

Initialwoodtreatment . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . .

In-place wood treatment above ground ....................................................

Wood pole treatment at or below the ground line. ..........................................

SECTION VII-METAL POLES

Metalpoleusage . . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . .

Distribution line metal poles..............................................................

Transmission line metal towers ...........................................................

Pole-linemetalhardware. . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . .

Paintingofmetalpoles . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . .

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SECTION VIII-CONCRETE POLES

Concrete pole overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Concrete pole foundations ................................................................

SECTION IX-OVERHEAD OPEN WIRE CONDUCTORSOverhead conductor construction.

.........................................................

Overheadconductormaterial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Overhead conductor covering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Overheadconductorsag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Overheadconductordamage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Overheadconductorrepairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION X-OVERHEAD CABLEOverhead cable construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Overhead cable repair requirements. ......................................................

SECTION XI-CONDUCTOR CONNECTIONSOverhead line conductor requirements.

....................................................

Overhead line conductor splices. ..........................................................

Overhead line connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Overheadline armor rods _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SECTION XII-POLE-LINE INSULATORS

Pole-line insulator related material. .......................................................

Insulator operating performance.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Types of pole-line insulators... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Pole-line insulator class requirements

.....................................................

SECTION XII I -GUYSGuy functional requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Guy strand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Anchor assemblies.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Guy attachments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Guystraininsulators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION XIV-TREE TRIMMINGTree trimming objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Treetrimming clearances and climbing space . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Tree trimmingtool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Typesoftreetrimming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Tree trimming instructions.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Treating a tree trimming wound

..........................................................

Treeremovalmethods......, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Tree kill ing chemicals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Poisonousplant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION XV-LIVE-LINE MAINTENANCELive-line maintenance requirements.

......................................................

Categories of energized-line maintenance..................................................

Energized-linemethods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Live-line operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION XVI-AERIAL LIFT REQUIREMENTSAerial lift construction

...................................................................

Aerial lift specifics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .CHAPTER 5. UNDERGROUND AND SUBMARIK E CABLES

SECTION I-ASSOCIATED GUIDANCE

Relevant cable guidance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

General construction guidance ............................................................

SECTION II-SAFETY PRECAUTIONSCablesafety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Structure safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION III-INSPECTIONFrequency of underground system inspections.

.............................................

Structureinspections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Cableinspections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Underground equipment inspections

......................................................

4-304-31

4-15

4-15

4-32 4-16

4-33 4-16

4-34 4-16

4-35 4-16

4-36 4-17

4-37 4-18

4-38 4-184-39 4-18

4-40 4-184-41 4-194-42 4-204-43 4-22

4-44 4-22

4-45 4-224-46 4-224-47 4-24

4-48 4-254-49 4-254-50 4-254-51 4-264-52 4-27

4-53 4-294-54 4-304-55 4-31

4-56 4-314-57 4-324-58 4-32

4-59 4-324-60 4-33

4-61 4-33

4-62 4-33

4-63 4-33

4-64 4-34

4-65 4-34

4-66 4-35

4-67 4-35

5-l 5-l

5-2 5- l

5-3 5-2

5-4 5-2

5-5

5-6

5-7

5-8

5-3

5-3

5-3

5-3

. . .

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SECTION IV-MAINTENANCE AND REPAIR OF DUCT SYSTEMS

Structure maintenance and repair ........................................................

Duct line maintenance and repair.........................................................

SECTION V-CABLE FAULTS AND FAULT LOCATIONSCable faults.. . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . .

Visual methods of cable fault locating.....................................................

Determining type of cable fault ...........................................................

Cable fault locating test methods .........................................................Simplifying cable fault locating...........................................................

Cable fault locating equipment............................................................

Tracing the cable fault signal.............................................................

Selecting cable fault locating methods.....................................................

SECTION VI-CABLE REPAIRUndergroundcablerepairs . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. .

Submarinecablerepai rs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Cablerepairsafety . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . .

Makingcablerepairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Solid dielectric cable repairs..............................................................

Other cable insulation and covering repairs. ...............................................

Othercablecomponentrepairs . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .

SECTION VII-CABLE TESTINGCabletests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Cable insulation resistance tests..........................................................

Cable overvoltagetests . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . .. . . . . . . .Cable power factortests . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . .. . . . .Cablemoisturetests . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . . . . .

Cabletestrecords . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION IX-UNDERGROUND CORROSION CONTROLImportanceofcorrosioncontrol . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .

Types of corrosion . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . .

Prevention of corrosion . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . . . . . .

CHAPTER 6. OUTDOOR LIGHTING

SECTION I-LIGHTING AND CIRCUIT TYPES

Outdoorlightinguse . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . .. . . . . . . .Types of lighting circuits..................................................................

SECTION II-MULTIPLE TYPE LIGHTINGMultiple type lighting system components .................................................

Luminaires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Lamptypes. . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . .Luminaire components.. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . . .

Luminairemaintenance . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . . .

Multiple type lighting controls............................................................

SECTION III-LIGHT DISTRIBUTION

Light distribution standards..............................................................

Roadway lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Floodlighting . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . .

Airfield l ighting. . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . .

SECTION IV-SERIES TYPE AIRFIELD LIGHTINGSeries type lighting system components ...................................................

Series type lighting control and protection .................................................

Series type lighting power supply equipment...............................................

Maintenance and troubleshooting series type lighting. ......................................

CHAPTER 7. TRANSFORMERS AND REGULATORS

SECTION I-CONSIDERATIONS

Voltage provisions covered..................................................~ . . . . . . . . . . . . .

Defining transformer and regulator characteristics.........................................

Transformerclassification.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Paragraph Page

5-95-10

5-11

5-12

5-13

5-145-15

5-16

5-175-18

5-19 5-105-20 5-105-2 1 5-11

5-22 5-11

5-23 5-12

5-24 5-12

5-25 5-13

5-26 5-145-27 5-14

5-28 5-155-29 5-165-30 5-17

5-31 5-17

5-32 5-185-33 5-185-34 5-18

6-16-2

6- l6- l

6-3 6- l6-4 6- l6-5 6-l

6-6 6-2

6-7 6-26-8 6-3

6-9

6-106-11

6-12

6-136-14

6-15

6-16

6-6

6-6

6-7

7-1

7-2

7-3

7-l

7-l

7-l

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SECTION I I -MAINTENANCETransformer inspection and maintenance frequencies. ......................................

Transformer inspectionss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Transformer testing guidance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Solid (winding) insulation tests ...........................................................

Transformer insulation liquids. ...........................................................

CHAPTER 8.OVERCURRENT PROTECTIVE AND SWITCHI NG DEVICES

SECTION I-CONSIDERATIONSCircuit interrupting devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Location of protective and switching devices ...............................................

Protective and switching device instruction manuals .......................................

Protective and switching device records. ...................................................

SECTION I I -FUSESFuseusage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Fuse operating safety considerations ......................................................

Fuse replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Fuse maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION III-SWITCHESSwitchusage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Operationofswitches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Switch maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION IV-CIRCUIT BREAKERSCircuitbreakerusage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Frequency of circuit breaker maintenance .................................................

Maintenance of nonmetalclad switchgear circuit breakers. ..................................

Maintenance of metalclad circuit breakers .................................................

Maintenance of low-voltage power circuit breakers .........................................

Repairofcircuitbreakers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION V-MISCELLANEOUS DEVICESCircuit switchers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Automaticcircuitreclosers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

CHAPTER 9. OVERVOLTAGE PROTECTION

SECTION I-CONSIDERATIONS

Overvoltage protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Lightning-induced voltage surges .........................................................System operating voltage disturbances ....................................................

Surge limiting protective device requirements. .............................................

SECTION II-SURGE (LIGHTNING) ARRESTERSDefinition of a surge arrester .............................................................

Typesofsurgearresters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Classification of surge arresters. ..........................................................

Maintenance of surge arresters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION III-OTHER DEVICES

Surgeshieldingdevices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Surge capacitors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Surgeprotectivegaps.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Surgebypassresistors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

CHAPTER 10. GROUNDING

SECTION I-CONSIDERATIONSBasic principles of grounding .............................................................

Groundingprovisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION I I -MAINTENANCEGroundingmaintenancesafety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Visual inspection of grounds ..............................................................

Galvanic corrosion of grounds. ............................................................

SECTION I I I -TESTINGGround resistance tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Groundvaluemeasurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Paragraph Page

7-4 7-2

7-5 7-3

7-6 7-6

7-7 7-6

7-8 7-7

8- l

8-28-3

8-4

8-1

8-1

8-18-1

8-5

8-7

8-8

8-18-28-28-3

8-9

8-108-11

8-3

8-128-13

8-l48-l58-16

8-l7

8-68-68-7

8-108-12

8-12

8-18 8-14

8-l9 8-14

9- l9-29-39-4

9-5

9-79-8

9-9

9-109-11

9-12

10-l

10-2

10-310-4

10-5

10-6

10-7

9-l9-19- l

9- l

9- l

9- l9-29-2

9-2

9-3

9-3

9-3

10-l

10-l

10-l10-l

10-2

10-2

10-2

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Methods of measuring ground resistances..................................................Methods of reducing ground resistances

...................................................

CHAPTER 11. RELAYS AND CONTROLS

SECTION I--RELAYS, ELECTRIC POWER APPARATUSRelayfunctions. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . . .Relayfundamentals . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . .Relayconstruction . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . .Relaymaintenanceperiods . . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . .

Relaygeneralfieldinspection . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . .Relay performance tests . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . .

Common electromechanical relay tests.....................................................Relaytestequipment . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . .

Relay repairs . . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. .

SECTION II-CONTROLS

Control functions.. . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . .

Preventive maintenance and inspections of controls ........................................Troubleshootingcontrols . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . .

CHAPTER 12. INSTRUMENTS AND METERS

SECTION I-CONSIDERATIONSElectrical Instruments....................................... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Electricalmeters . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .

Validity of electrical measurements........................................................Fixed installations of instruments and meters. .............................................

Portable instruments and meters .........................................................Inspections of instruments and meters

....................................................

Tests of instruments and meters ..........................................................

SECTION II-PREVENTIVE MAINTENANCE

Mounting of instruments and meters ......................................................Installation of instruments and meters

....................................................

Maintenance of instruments and meters...................................................

SECTION III -CALIBRATION AND ADJ USTMENTAccuracy check of instruments and meters .................................................Adjustment of instruments and meters

...................................................

SECTION IV-REPAIRS

Paragraph Page

10-8 10-210-9 10-4

11-l 11-l

11-2 11-l

11-3 11-l

11-4. 11-211-5 11-211-6 11-311-7 11-3

11-8 11-4

11-9 11-5

11-10 11-6

11-11 11-711-12 11-8

12-l 12-1

12-2 12-1

12-3 12-112-4 12-1

12-5 12-1

12-6 12-1

12-7 12-1

12-8

12-912-10

12-2

12-212-2

12-11

12-12

12-2

12-2

Field repairs of instruments and meters...................................................

Shop repairs of instruments and meters...................................................

SECTION V-TROUBLESHOOTINGTemperature influence on instruments and meters .........................................Stray-field influence on instruments and meters ...........................................Calibration of instruments and meters

....................................................

Other instrument and meter considerations ................................................

CHAPTER 13. POWER CAPACITORS

SECTION I-CONSIDERATIONSDescription of power capacitors

...........................................................

Types of power capacitors . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . .

Application of power capacitors...........................................................

Permissible power capacitors dielectrics...................................................

SECTION II-MAINTENANCE AND INSPECTIONEnsuring safe capacitor deenergizing ......................................................Power capacitor inspection schedule

.......................................................

Ventilation of power capacitors............................................................

Temperature influence on power capacitors................................................

Exposure influence on power capacitors ...................................................

Voltage influence on power capacitors.....................................................

Fusesforpowercapacitors . . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . .

SECTION I I I -TESTS

12-13 12-412-14 12-4

12-15 12-5

12-16 12-5

12-17 12-6

12-18 12-6

13-l 13-1

13-2 13-1

13-3 13-1

13-4 13-1

13-5 13-1

13-6 13-1

13-7 13-1

13-8 13-2

13-9 13-2

13-10 13-2

13-11 13-2

Field tests for power capacitors........................................................... 13-12 13-2

Terminal tests of power capacitors........................................................ 13-13 13-3

Leak tests of power capacitors............................................................

13-14 13-3

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CHAPTER 14. STORAGE BATTERI ES

SECTION I-CONSIDERATIONSBattery usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Battery types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Batterysafety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .General battery maintenance procedures

..................................................

SECTION II-FLOODED LEAD-ACID BATTERY MAINTENANCE

Visual inspections of batteries ............................................................Measurements of battery condition.

.......................................................

Battery maintenance specifics .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..Testingofbatteries. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION III-FLOODED LEAD-ACID BATTERY CHARGINGBattery charging precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Battery charging considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Normal floating battery charge .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Equal izing battery charge .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION IV-VALVE-REGULATED LEAD-ACID CELL BATTERIESValve-regulated cell differences

...........................................................

Charging or valve-regulated cells .........................................................

Temperature compensation for valve regulated cells ........................................

SECTION V-Nickel-cadmium cell batteriesDescription of nickel-cadmium batteries

...................................................

Requirements for nickel-cadmium batteries ................................................

SECTION VI-CHECKS AND TROUBLESHOOTINGInspectionsofbatteries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Troubleshooting batteries. ................................................................

SECTION VII-BATTERY CHARGING EQUIPMENTBatterychargingrequirement .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..

Rectifier type battery chargers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Accessories for battery chargers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Maintenanceofbatterychargers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION VIII-PLACING A NEW BATTERY IN SERVICE

Placing lead-acid batteries in service ......................................................Placing nickel-cadmium batteries in service.

...............................................

Connections for batteries .................................................................

SECTION IX-PUTTING A BATTERY IN STORAGE

Batterystorageprocedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Periodic check of a stored battery .........................................................

SECTION X-REPLACEMENT AND DISPOSALReplacementofa battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

D isposal of batter ies.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

CHAPTER 15. TOOLS AND EQUIPMENT

SECTION I -USEElectrical tools and equipment standards

..................................................

Tools and equipment classification ........................................................

Tools and equipment safeuse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION II-HAZARDOUS MATERIAL PROCEDURESHazardous substances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Asbestos containing materials .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..

Polycholorinated biphenyl (PCB)insulated equipment ......................................

Sulfur hexifluoride (SF,) insulated equipment. .............................................

Chemicals used for outside maintenance. ..................................................

SECTION III-PROTECTIVE EQUIPMENT

Protective electrical rubber goods .........................................................

Helmets for electrical work ...............................................................

Barrier protection for electrical work ......................................................

Visual warnings for electrical work. .......................................................

Protective grounding of deenergized lines. .................................................

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Insulation resistance conversion factors to 20C ......................................................

Satisfactorypowerfactors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Troubleshooting chart for oil problems. ..............................................................

Troubleshooting chart for power circuit breakers .....................................................

Typical laboratory relay test equipment .............................................................

Troubleshooting chart for general control equipment. .................................................

Troubleshooting chart for indicating instruments. ....................................................

Troubleshooting chart for recording instruments and meters ..........................................

Maximum ambient temperatures for continuous operation ............................................Capacitor bank oil switch maintenance ..............................................................

Battery room warning notice. .......................................................................

Suggested test accessory list for battery maintenance. ................................................

Equalizingcharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Charging of nickel-cadmium batteries ...............................................................

Suggested list of minimum facility-wide field test equipment. .........................................

Harmonic distortion limits. .........................................................................

Maintenancefrequencie . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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CHAPTER 1

INTRODUCTION

Section I - PRIMARY CONSIDERATIONS

1-1. Purpose and scope.

This manual provides guidance for the maintenanceand repair of exterior electrical distribution sys-tems. New construction of exterior electrical facil-ities, even when funded from maintenance appro-priations, should comply with the appropriatedesign criteria. These systems include substations,overhead and underground electrical distributionsystems, exterior lighting systems, and electricalapparatus and components. Guidance for genera-tors and interior electrical systems (600 volts andless) are covered in the following publications:

a. TM 5-683/NAVFAC MO-ll6/AF J MAN32-1083.

b. TM 5-685/NAVFAC MO-912.

c. MIL-HDBK-1003A/ll.

1-2.References.

Appendix A contains a list of references used in thismanual.

1-3.Application of codes and publications.

The information in this manual should not super-sede equipment manufacturers instructions and re-quirements. When conflicts exist the most rigorousrequirement should be followed. A11 maintenanceand repair of electrical systems should be performedin such a manner that the completed work willconform to the publications listed below to the de-gree indicated.

a. Cod es.The l isted codes and standard containrules (both mandatory and advisory) for the safeinstallation, maintenance, and operation of electri-cal systems and equipment.

(1) The National Electrical Code (NEC), NFPA

70.(2) The National Electrical Safety Code

(NESC), ANSI C2.

(3) Occupational Safety and Health (OSHA),General Industry Standards, 29 CFR 1910.

b. Nongovernment publications. Other nongov-ernment publications referenced in this manual ex-pand guidance in line with recognized industrystandards. The most extended coverage on recom-mended practices for electrical equipment mainte-nance, and one that should be used in conjunction

with both the NEC and the NESC, is NFPA 70B.Publication NFPA 70B is recommended as a useful

reference in preparing contract requirements for

maintenance to be done by outside service agencies.

1-4. Standards of maintenance.

Electrical systems will be regularly maintained toensure continued compliance with the codes andpublications referred to in appendix A. Such main-tenance will prevent system and equipment failuresand ensure maximum safety and efficiency in theutilization of the facilities. At each installation, aprogram for proper maintenance should be estab-lished and effectively followed. This program shouldinclude the scope of work, intervals of performance,

and methods of application including safety require-ments, practices and procedures. When a number ofitems require servicing or renewal over a period ofyears, a proportionate number should be main-tained each year. For instance, if there are 100transformers on the system, requiring maintenanceat 5-year intervals, the work should be performedon 20 transformers each year.a. Pr edi cti ve mai nt enan ce. A predictive mainte-

nance program is more desirable than routine re-curring maintenance. Predictive testing should oc-cur periodically but actual maintenance or

replacement should take place only when necessary.An automated testing and record management sys-tem should be utilized where available. Where sucha system is not available, its acquisition is recom-mended.

b. Sample testing formats. Testing formats forcable, circuit breakers, switchgear, and transform-ers are provided in NFPA 70B. These formats can berevised as needed for local requirements.

1-5. Maintenance responsibilities.

Anadequate supply of dependable electrical energyis essential for the accomplishment of the installa-tion mission. Adherence to a well planned and wellorganized maintenance program, including the es-tablishment of specific goals and follow-up proce-dures will ensure the proper functioning of theequipment in the electrical distribution system.

a. E l ectr i cal super visor . As used in this manual,the title electrical supervisor indicates the indi-vidual assigned the responsibility for maintenanceof electrical distribution systems and equipment.

The maintenance of electrical distribution systems

is the responsibility of the installations commanderand a specific duty of an Army director of public

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works, a Navy public works officer, or an Air Forcebase engineer. Operation and maintenance are asingle staff responsibility, and frequently the same

personnel will perform both functions.

b. El ectri cal super visor

trical supervisor will:responsibil i t ies. The elec-

(1)Initiate positive action to remove, or reduce

to a minimum, the cause of recurrent maintenanceproblems.

(2) Carry out maintenance inspections and ser-vices so there is a minimum of interference withuser activities.

(3) Provide for the accomplishment of as muchwork as possible during each maintenance visit, andensure that spot checks, inspections, and repairsare made on all components of the electrical facil-ities.

(4) Ensure that an adequate set of up-to-daterecords are maintained for each major component ofall systems.

(5) Develop standard operating procedureswhich are in compliance with applicable safety re-quirements.

(6) Train maintenance personnel to improvetheir efficiency and to observe safety requirements.

1-6. Maintenance records.

One of the most important sources of informationfor aiding inspections, maintenance, or tests is acomprehensive file of equipment and service

records. In addition to indicating basic informationrequired for proper inspection of the equipment,these records will indicate where trouble has beenexperienced and where special procedures may bewarranted.

a. Equi pment docum ent s. There are a variety ofdocuments which indicate the equipment providedand how to keep it operating properly. These docu-ments should be provided when new facilities arebuilt, or existing facilities modified. These recordsshould be obtained from the construction agency assoon as possible, preferably before the electrical su-pervisor accepts maintenance responsibility. Thesedocuments should address any warranty provisionsapplicable to the equipment. Equipment documentsdetermine maintenance practices and should be in-cluded as a part of the maintenance records of thefacility. The most common documents are listed be-low.

(1)I ns t ruc t ion l ea f lets and m anua l s. Eachpiece of major electrical equipment purchased

should be accompanied by an instruction leaflet ormanual outlining the desired methods of installa-

tion, operation, and maintenance. These instruc-tions contain valuable information on maintenance

practices, part designations, and ordering proce-

dures. Spare parts lists are a vital part of these

records.

(2) In sta l l a t ion draw ings. Maintenance is often

affected by the manner in which the equipment isinstalled. For convenience, and as a means of expe-diting maintenance, as-built installation drawings

should be readily accessible to maintenance andinspection personnel.

(3) Wir ing diagram s. Adequate and up-to-datewiring diagrams are important for proper mainte-nance. Diagrams facilitate locating troubles, whichotherwise may require extensive probing and test-ing procedures. Such diagrams should be readilyavailable to maintenance personnel.

(4) Di str i but ion m aps. Maps showing locationsof distribution lines, wire sizes, transformer sizes,pole numbers, voltage classes, and sectionalizingdevices are vital. Up-to-date distribution mapsmounted on the maintenance or electrical shop wallare very useful.

b. Ser vi ce r ecor ds. Service records constitute ahistory of all work performed on each item of equip-ment and are helpful in determining the overallcondition and reliability of the electrical facilities.Service records should show type of work (visualinspection, routine maintenance, tests, repair), testresults (load, voltage, amperes, temperature), andany other remarks deemed suitable. It is highlyrecommended that service records should include a

log of incidents and emergency operating proce-dures.

(1) L ogs of in cident s. Logs of incidents, such aspower failures, surges, low voltage, or other systemdisturbances are very useful in planning and justi-fying corrective action.

(2) Emergency operating instructions. Emer-gency work on electrical facilities is safer andquicker when instructions are prepared and postedin advance. Instructions should be prepared foreach general type of anticipated emergency, statingwhat each employee will do, setting up alternatives

for key personnel, and establishing follow-up proce-dures. Instructions should be posted in the electri-cal shop, security guard office, substations, operat-ing areas, and such other locations as theresponsible supervisor deems advisable. Employeesshould be 1isted by name, title, and official tele-phone number. These instructions should empha-size safety under conditions of stress, power inter-ruptions, and similar emergencies.

1-7. Priority and scheduling.

a. Pri ori ty. In regard to the support of the instal-lation physical plant, it is the policy of the military

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departments that, in order of priority, maintenance manders to meet local requirements. Service in-should be second only to operations. It must be tervals may be lengthened only when justified bysystematic, and it must be timely. extenuating circumstances. Whenever service inter-b. Scheduling. The following chapters provide vals or other guidance in this manual differs from

data on service intervals, procedures, and practices. information supplied by the manufacturer, the more

Modifications may be made by installation com- stringent procedure should be followed.Section II - SAFETY

1-8. Minimizing hazards.

Material specifications, construction criteria, instal-lation standards, and safe working procedures havebeen developed to minimize hazards. All work andmaterials should conform to the latest accepted pro-cedures and standards, as defined in publicationslisted or referred to in this manual.

1-9. Qualification of electrical workers.

Due to the inherent hazards encountered in themaintenance of electrical distribution systems and

equipment, it is essential that all electrical workersbe thoroughly trained and be familiar with theequipment and procedures to be followed.

1-10. Certification of electric workers.

Properly trained electric workers will be certified inaccordance with applicable publications.

1-11. Public safety.

All necessary precautions will be taken to warn thepublic of electrical hazards or other conditions

which may constitute a danger. This is especiallytrue of temporary hazards due to work in progress.

1-12. Personnel safety.

Any work on or close to electrical equipment of anykind should be considered dangerous and propersafety precautions will be taken. All personnel whoperform work of any kind on or near electricalequipment must be familiar with and observe allsafety precautions.

a. Safety fi r st. Tw o safety rules are mandatory asfollows:

(1) Consider all electrical equipment to be en-ergized until it is known positively (as by the pres-ence of grounding clamps) that it is not energized.Comply with regulations and safety instructionscontained in NEC and NESC, the applicable depart-mental publications, and special publications issuedby the local command.

(2) Work may be done on energized lines andequipment only by personnel qualified by their jobdescriptions for that voltage level. J ob descriptionsshould require actual hands-on work service periods

which meet local uti lity and the InternationalBrotherhood of Electrical Workers approval. All

tools and equipment must be maintained in proper

operating order, be suitable for the maximum volt-

age level involved, and should be periodically tested

for compliance with all safety requirements. De-partmental publications should be consulted for

specific requirements in each voltage level.

b. Ser vi ce safety m anua l s.This manual addresses

some safety requirements, but users should also be

familiar with the service safety manuals TM 5-682,NAVFAC P-1060, and AFMAN 32-1078.

c.Per sonal pr otective temporar y ground in g. Thisis temporary grounding installed to protect workersengaged in de-energized line maintenance. Thegrounds are provided to limit the voltage differencebetween any two accessible points at the work siteto a safe value. An expanded discussion of protectivegrounding principles and practices is contained inIEEE 1048, NF PA 70B and The Linemans andCablemans Handbook.

1-13. Live-line maintenance.

Aerial live lines are energized lines that are being

tested, repaired, and maintained more and more byelectrical utilities to reduce the number of outagesor service interruptions. The use of such procedureson DOD installations requires that good practice befollowed and that there is no conflict with localfacility rules.

a. Good pr acti ce. Personnel doing live-line workshould have satisfactorily completed a formal train-ing course of instruction and be examined periodi-cally. Live-line maintenance usually means anymaintenance activity performed on energized elec-trical conductors or equipment with a phase-to-

phase voltage exceeding 600 volts. I t usually doesnot include such activities as switching, hardwaretightening, climbing, hole digging, pole setting, con-ductor stringing, etc. The performance of this workrequires equipment and tools that meet applicableindustry standards for energized-line maintenance.

b. L oca l facil it y rul es.Two considerations affectfacility rules on the type and extent of live-linemaintenance permitted: availability of qualified fa-cility personnel and equipment versus the facilitysrequirement for uninterrupted operation. I f local

missions prevent electrical power shutdowns andlocal facilities are not qualified to perform live-line

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work, then a live-line contractor may need to be and are not intended to substitute for training orhired on a scheduled and/or a nonscheduled basis. operating procedures; for meeting specific industryGeneral energized-line maintenance practices cov- guidelines; or for meeting federal, state, local, orered in chapter 4, section VI , serve only as a guide facility regulations and rules.

Section III - AVOIDING PROBLEMS

1-14.Operating conditions.

Always observe the four cardinal rules of electricalmaintenance.

a.Keep the equipment clean.b. Keep the equipment dry or lubricated as ap-

propriate to the part.c.Keep screwed parts tight.d.Prevent friction on moving parts.

1-15. Detecting potential trouble.

Diagnostic devices, where available, allow checkingthe system for potential trouble before it occurs.Potential problems may also be detected by the use

of four of our five senses: see, hear, touch, and smell.a. See. Many abnormal conditions can be de-

tected by visual inspection: some of the patternsidentifiable by sight are cleanliness, distortion,color, misalignment, size, and position.

b. Hear . Changes in the intensity of noise, pitch,or frequency are significant clues to operationalchanges and possible malfunctions. Some of thesound patterns that may indicate malfunctioningare squeaking, rattling, knocking, and whistling.c. T ouch. Among the damaging characteristics

which may be identified by touch are vibration, wet-ness, and heat. Caution should be exercised intouching components which are normally hotenough to burn personnel on contact or live partswith hazardous potentials.

d. S m el l . Burning insulation and battery fumesprovide distinctive odors which signal component

deterioration.

1-16. Electrical connections.

Connections are an essential part of any electriccircuit. Good electrical contact is essential. Dirt isthe enemy of good contact. Whenever an electricalconnection is to be made, extreme care must betaken to ensure all dirt, rust, corrosion, insulation,oil, and other contaminants are removed. The con-tact surfaces should be bright, clean metal. Thisrequirement applies to connections made by solder-ing, clamps, twisted sleeves, compression fittings, orany other method.a.A l um i n um . Connections of aluminum items

should always include the application of a joint com-

pound which will ensure metallic contact by dissolv-ing the aluminum oxide which is always present onaluminum and aluminum alloy surfaces in air. Thecontact surfaces of aluminum conductors and con-nectors should first be vigorously cleaned with astainless steel wire brush to a bright finish andthen immediately coated with the aluminum-oxideinhibiting compound.

b. Copper. Copper contact surfaces should becleaned, but not connector barrels. The barrelsshould be cleaned on the inside.c.Di ssim i l ar metals. Only connectors designed

for the purpose should be used to connect aluminumand copper items.

d .Testi ng. Accessible connections may be testedusing an infrared detector only if the connection isunder load as covered in chapter 3, section I.

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Section II - REQUIREMENTS

2-4. Electric workers, instruments, and re-

ports.

Tests of electrical equipment should be performedunder the supervision of qualified electric workers.I f in-house personnel are not available for these

tests, the services of a qualified electrical testing

agency may be used.a. Test ing agency qual i f icat ions. The testing

agency should submit proof that it is a corporatelyindependent testing organization which can func-tion as an unbiased testing authority, professionally

independent of the manufacturers, suppliers, andinstallers of equipment or systems evaluated by thetesting firm. The testing agency should meet OSHAcriteria for accreditation of testing laboratories,

Title 29, Part 1910-7; or be a full member companyof the InterNational Electrical Testing Association(NETA) and be regularly engaged in the testing of

electrical equipment devices, installations, and sys-tems. The lead technical agency member on-siteshould be currently certified by NETA or the Na-tional Institute for Certi fication in EngineeringTechnologies (NICET) in electrical power distribu-tion system testing.b. Test instrument calibrations. I nstruments

should have been calibrated within the last 12months except that analog instruments should have

been calibrated within the last 6 months. Calibra-tion should provide the full-scale accuracy based on

the manufacturers data, usually 1 percent forswitchboard instruments and 0.25 percent for por-table instruments. Dated calibration labels shouldbe visible and up-to-date calibration records, in-structions, and procedures should be maintained foreach instrument which should have had a calibrat-

ing standard of higher accuracy than that of the testinstrument.

c.Test r eport s. A dated test report should include,as a minimum, the following data:

(1) Summary of project findings and recom-mendations, if required for additional work.

(2) Description of equipment tested.(3) Description of test.

(4) Test results.

2-5. Frequency of inspection.

The intervals given in this manual and/or by manu-facturers maintenance recommendations should beconsidered an initial interval for normal conditions.Intervals should be shortened where adverse condi-

tions exist and may be lengthened only where expe-rience under better-than-normal conditions show

this can be done safely. The frequency of inspectionmay vary for similar equipment operating underdifferent conditions. Critical equipment, heavilyloaded apparatus, operator handled, and intermit-

tently operated units are examples of different op-erating conditions.

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TM 5-684/NAVFAC MO-200/AFJMAN 32-1082

CHAPTER 3

TRANSMISSION AND DISTRIBUTION SUBSTATIONS

Section I - GOVERNING CONSIDERATIONS

3-1. Type of substations covered.

This chapter includes a transmission and distribu-tion substation which is an assemblage of equip-

ment for purposes other than generation or utiliza-tion, through which electrical energy in bulk is

passed for the purpose of switching or modifying its

characteristics.

3-2. Electrical system relationship.

A substation is an integral and vital part of anelectrical system. I t does not exist independently of

the rest of the system, though it is usually designed

so that a failure of a single component will notinterrupt loads, except for switching times. Such

interruption may force greater than normal loads tobe carried by other components of the station whilerepairs are being made. Most substations are de-

signed so they do not require attendant personnelon a continuous basis. Supervisory control and data

acquisition (SCADA) systems, where provided, al-low monitoring at a central point.

3-3. Substation safety concerns.

Substations present a potential safety hazard, ow-

ing to the large amount of energized conductor sur-face concentrated in a relatively small area. In gen-eral, only portions of an entire substation can bede-energized, although scheduled outages may berequired for equipment which can not be bypassedor worked on while energized. All inspecting andrepairing personnel must be thoroughly trained.The following requirements are minimum:

a. Familiarity with operating procedures, protec-tive and interlocking schemes, and the equipmentcapabilities at the specific substation.

b. Knowledge of the proper use of safety equip-ment, first aid procedures and equipment, andequipment grounding techniques.

c.Access to safeguards such as danger signs, tem-

porary barriers, protective clothing, tools and pro-tective equipment, and all safety manuals andrules. Procedures should clearly indicate insulatingrequirements and working clearances for any cat-egory of energized-line maintenance employed.

d. Keeping proper inspection records and check-lists so that observed defects or improper conditions

not immediately repairable will be promptly cor-rected.

3-4. Substation security.

In addition to the personnel safety hazards men-tioned above, an electrical substation presents an

attraction to would-be vandals, dissidents, or other

belligerents. For these reasons, good security is a

basic requirement. All means of access to substa-tions, including buildings and yards, will be kept

locked when unoccupied and secure when occupied

by authorized personnel.

3-5. Periodic inspections of substations.

Aninspection checklist, tailored to a specific substa-

tion and containing all items to be checked, is rec-ommended. Monthly visual and yearly infrared in-spections of the entire substation are recommended.

3-6. Visual inspections of substations.

Visual inspections should include the total substa-tion area including the site, the control house, and

all equipment and structures. The energized sub-station should be inspected from ground level, to

ensure adequate safety clearances from energized

parts. Binoculars should be used to view buses andother equipment located on structures. Special care

should be used when ground connections arechecked, since a high voltage could develop across

any gap created between a ground cable and a piece

of equipment, particularly under fault conditions.For this reason, ground connections shall not be

removed for any reason while the substation is en-ergized.

3-7. Infrared inspections of substations.

All matter emits infrared rays in proportion to its

temperature.

a. Method. An infrared detecting device can beused to determine loose connections, overloading of

conductors, localized overheating in equipment, or

similar conditions before they become serious. Some

equipment is sensitive to a fraction of a degree.Infrared inspection can be done from a distance,since contact with the item being measured is notrequired. Substation equipment, such as bare bus,disconnect switches, and connections, can bechecked without being de-energized. The inspectionis made by aiming the infrared detector at various

areas of the substation and noting where the hotspots are.

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b. Equi pment. Several types of infrared detectorsare available. These vary from a simple hand-heldinstrument similar to a gun, through which the op-

erator can detect hot spots and note their locations,to complex equipment requiring qualified operators

and product photographs as a permanent record of

the area being checked. The simpler detectors areusually sold outright, while the complex items are

usually used by infrared detection services whichcontract to do the work. Having an instrumentreadily available can be justified for a large instal-lation with several substations, while a contract tohave a survey performed would probably be betterfor a small installation. However, as a low cost al-ternative, a camera with infrared sensitive filmmay be used, or a self-calibrating portable indicat-ing unit can be coordinated with a Polaroid camera.

c. Su r veys. When infrared (thermographic) sur-veys are made, the equipment to be scanned mustbe identified. Scanning should be made after visual

and mechanical conditions have been observed. Re-port all areas scanned.

(1)Reports. I f hot spots are found the reportshould locate the problem area and the temperature

rise above a reference 30 degrees C. The cause of

the heat rise should be identified such as phase

unbalance, overload, poor connections, or other heat

producing conditions.

(2) Test parameters. Equipment must detect

emitted radiation and convert to a visual signal. A

detection ability of a one degree C rise between the

hot spot area and the 30 degree reference area isrequired.

(3) H ot spot i nd icati ons. NETA-MTS indicates

that temperature gradients as shown in table 3-l

will require the following actions.

Tabl e 3-l. Infr ared hot spot grad ients1

Temperature

gradient

0 to 3C

4 to 3C

16C and above

Deficiency ActionPossible Investigate

Probable Repair as time permits

Major Repair immediately

1Consider providing photographs an&or thermograms as seen onthe imaging system in reports where appropriate to the size and

criticality of the equipment examined.

Section II - STRUCTURE MAINTENANCE

3-8. Importance of maintenance.

The useful l ife of a substation structure is directlydependent upon the care it receives. Surface preser-vation is of prime importance.

3-9.Galvanized steel structures.The protective coating produced by the galvanizingprocess normally has a long life; however, the coat-ing will eventually fail and rust will appear. The lifeof the coating on structural steel used in substa-tions should generally be longer than 12 years ex-cept possibly for the upper flat surfaces of horizon-tal members. Any failure of the coating will usuallyoccur in spots rather than over an entire surface.Refer to chapter 4, section VI I for self-weathering

steel requirements.

a.Cleaning.Clean the surface with a wire brushor by other mechanical means to remove rust anddirt. I f the surface is contaminated with grease oroil, a solvent should be used to remove those con-taminants. Mineral spirits or one ounce (28.4

grams) of trisodium phosphate in one gallon (3.8liters) of warm water can be used as the solvent. I fit is uneconomical or impractical to remove all rust,

a reasonably satisfactory job can be obtained bydeactivating the rust through chemical treatment. Aweak solution of phosphoric acid is suggested fordeactivating rust. Use proper skin and eye protec-

tion.

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b. Pain ti ng. I f required spot painting covers more

than 5 percent of the visible surfaces, the entire

structure probably should be painted.

(1) Pri mi ng coat. Apply a priming coat to the

clean dry surface using a good zinc dust/zinc oxide

paint. Allow ample time for the paint to dry before

applying the finish coats.

(2) Fi ni sh coats. Two finish coats should be ap-

plied using the same type paint used for priming.

Ample drying time should be allowed between fin-

ish coats. Only one finish coat is needed for areas on

which the galvanized coating remains intact. Other

paints normally used as final coats for metal (such

as aluminum paint) may be used as the final coat inplace of the zinc dust/zinc oxide paint.

(3) Temperature. Painting of outdoor metalwork is recommended only when the temperature is

above 45 degrees F (7 degrees C) and when the

relative humidity is below 80 percent.

(4) Durab i l i t y . The durability of a paint coat-ing depends on thickness, cohesion, and contin-

uity. Generally, 5 mils or 0.005 inch (0.125 milli-

meters) is an adequate thickness. The thickness

should be uniform, and paint should not be

easily scraped off the metal. Welds, edges, and other

hard-to-coat areas should be given particular at-

tention.



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TM5-684/NAVFACMO-200/AFJMAN 32-1082

fill are usual coverings. For very large substationssome areas may be seeded for grass.a. Ground treatment. Removal of vegetation,

elimination of low spots in the yard, and control ofgrassed areas is necessary. I f grass is permitted,careful maintenance is necessary both for estheticsand safety reasons. I f allowed to grow uncontrolled,weeds, grass, or other plants create fire hazards,are unsightly, impede free action, and may grow tallenough to contact live parts and cause flashovers.Low spots collect debris and stagnant water. Where

chemical application for removal of vegetation isrequired, it should meet environmental require-ments.b. H ousekeepi ng. Miscellaneous storage should

not be permitted except in specific areas reservedfor this purpose. Storage should not interfere withoperations and should be in a protected, tidy, andaccessible manner. Birds may cause problems re-

quiring removal of nests and possible provision ofbird repellant controls such as tape, images, orsound systems.

Section IV - INSULATORS

3-19.Function of insulators.

The function of an insulator is to support a conduc-tor or conducting device safely. An insulator, beingof a nonconductive material, physically and electri-cally separates the supported item from anygrounded or energized conductors or devices.a. Composit ion and problems. I nsulators are

composed of porcelain, glass, fiberglass, or a com-posite compound. Maintenance is necessary to pre-serve their insulating ability which can be degradedby contamination or other damaging actions. Mostnsulator damage will result from gun shots; light-ning, surge, or contamination flashovers; and winddamage. Defective insulators can also cause visiblecorona or interference voltage propagation.

b. Relat ed mat er ial . Apparatus type insulatorsare provided in substations to support devices and

heavy lines. See chapter 4, section XI I , which pro-vides a discussion of insulation levels.

3-20.Tests of insulators.

Radio interference conditions may be detected byusing instruments designed for this purpose. Other-wise, maintenance tests on insulators are normallyimited to occasional power factor measurements atthe more important installations, where the loss ofthe facilities must be kept to an absolute minimum.Bus and switch insulators should be power-factortested in conjunction with similar testing of other

apparatus within the substation. Power factor testsare described in section VI I .

3-21. Inspection and repair of insulators.

Switch-and-bus apparatus type insulators are themost intricate type and require the highest degreeof reliability in service. This is because the several

pieces of porcelain and hardware, assembled in asingle unit, are usually located at key positions inthe systems, where failure is extremely serious.Switch-and-bus insulator failures occur when porce-ain is thrown in tension by any thermal movementbetween nested parts, which can cause cracking andallow the entrance of moisture. An accumulation of

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foreign deposits, and mechanical damage from ex-

ternal sources also cause deterioration. Evidence of

such impairments may cause a flashover punctureaccompanied by a destruction of insulator parts.Workers should be CAUTIONED that equipmentmust be de-energized unless the procedure in chap-

ter 4, section XV is authorized.a. Ceramic insulators. Ceramic insulators are

made of wet-process porcelain or toughened glass.

(1) Construction.

(a) Porcela inin sul ators. Porcelain insulatorsare manufactured from special clays to produce aplastic-like compound which is molded, oven dried,dipped in a colored glazing solution, and fired in akiln. The glossy surface of the glaze makes the in-sulator surface self-cleaning. Large porcelain insu-lators are made up of several shapes cemented to-

gether. A chemical reaction on the metal parts fromimproper cementing can result in a cement growthwhich can be sufficiently stressful to crack the por-celain.

(b)Glass insulators.. Glass insulators aremade from a mixture of sand, soda ash, and limewhich is mixed and melted in an oven, then molded,cooled, and annealed.

(2)Inspection.

(a)Look for fractures, chips, deposits of dirt,sa

Documents

1996 Us Army Facilities Engineering Electrical Exterior Facilities 201p