HB 239:2011

1 - HB 239:2011 GUIDANCE ON THE REPAIR AND OVERHAUL OF ELECTRICAL EQUIPMENT FOR EXPLOSIVE ATMOSPHERES
4 - PREFACE
5 - CONTENTS
9 - SECTION 1 GENERAL
9 - 1.1 SCOPE
9 - 1.2 REFERENCED DOCUMENTS
11 - SECTION 2 DEFINITIONS
11 - 2.1 GENERAL
11 - 2.2 ADDITIONAL DEFINITIONS
11 - 2.2.1 Verification Dossier
11 - 2.2.2 Metal spray (also known as thermal spray)
11 - 2.2.3 Laser welding
11 - 2.2.4 Solder
11 - 2.2.5 Controlled temperature burn-out
11 - 2.2.6 Final inspection
11 - 2.2.7 Competent person
12 - 2.2.8 Special processes
13 - SECTION 3 TECHNICAL PRINCIPLES AND PROCESSES
13 - 3.1 INTRODUCTION
13 - 3.2 BACKGROUND
13 - 3.3 COMPETENCIES
14 - 3.4 SERVICE FACILITY RELATIONSHIPS WITH THE EXPLOSION-PROTECTED EQUIPMENT OWNER/OPERATOR
15 - 3.5 CONSULTATION WITH OTHER PARTIES: MANUFACTURERS AND REGULATORS
15 - 3.6 DOCUMENTATION-VERIFICATION DOSSIER
16 - 3.7 TRANSITION OF STANDARDS
18 - 3.8 SELECTION OF SERVICE FACILITY
18 - 3.9 SERVICE FACILITY CAPABILITIES
19 - 3.10 WORK FLOW
19 - 3.10.1 Overview
21 - 3.10.2 Initial inspection
21 - 3.10.3 Failure analysis
21 - 3.10.4 Determination of conformity
21 - 3.10.5 Determination of pass/fail criteria
21 - 3.10.6 Exceptional circumstances
22 - 3.10.7 Resolution of Scope of Works
25 - 3.10.8 Changes to equipment
26 - 3.10.9 Repair
26 - 3.10.10 Verification of repair
27 - 3.10.11 Justification for the omission of verification tests
27 - 3.10.12 Final inspection
27 - 3.10.13 Equipment compliance reporting
28 - 3.10.14 Equipment compliance labelling
29 - 3.10.15 Pre-delivery inspection
29 - 3.11 COMMENTARY ON MATERIALS
29 - 3.11.1 Introduction
30 - 3.11.2 Aluminium and light alloys
30 - 3.11.3 Cast irons
30 - 3.11.4 Corrosion inhibitors (‘grease’) and their application
31 - 3.11.5 Insulation materials
31 - 3.11.6 Plastics and rubber
32 - 3.12 COMMENTARY ON INSPECTION TECHNIQUES
32 - 3.12.1 General
32 - 3.12.2 Mechanical inspection techniques and equipment
33 - 3.12.3 Electronic inspection techniques
33 - 3.13 MECHANICAL REPAIR PROCESSES
33 - 3.13.1 General
34 - 3.13.2 Welding
36 - 3.13.3 Metal spraying
36 - 3.13.4 Sleeving
36 - 3.13.5 Thread repair
37 - 3.13.6 Bolt fit-Fixing bolts, studs and nuts
38 - 3.13.7 Distortion repair
39 - SECTION 4 GENERIC TESTING PROCESSES FOR VERIFICATION OF EXPLOSION-PROTECTION TECHNIQUES
39 - 4.1 NON-DESTRUCTIVE TEST (NDT)
39 - 4.2 DIELECTRIC WITHSTAND (HIGH POTENTIAL OR HI-POT) TESTING
39 - 4.2.1 General
40 - 4.2.2 Hi-pot (high voltage, line frequency or Dielectric Withstand) test
41 - 4.3 INSULATION RESISTANCE
41 - 4.4 COMPONENT TESTING
41 - 4.4.1 Circuit breakers
41 - 4.4.2 Overloads
41 - 4.4.3 Current transformers
42 - 4.5 TEMPERATURE MEASUREMENT
43 - SECTION 5 OVERHAUL OF ROTATING MACHINES
43 - 5.1 GENERAL
43 - 5.2 REPAIR/OVERHAUL
44 - 5.3 OWNER/OPERATOR RESPONSIBILITIES
44 - 5.4 QUALITY-MANAGED ASSESSMENT STRATEGIES
45 - 5.5 EVALUATION PROCEDURES FOR ROTATING MACHINES
45 - 5.5.1 General
45 - 5.5.2 Before power shutdown (typically for large machines only, i.e. ≥1 MW
46 - 5.5.3 After shutdown
46 - 5.5.4 Before dismantling
48 - 5.5.5 Rewinding
48 - 5.5.6 Removal of windings
48 - 5.5.7 Before winding
49 - 5.6 ADDITIONAL NOTES FOR COPY WINDING
49 - 5.7 AFTER WINDING
50 - 5.8 REPAIR OF ROTORS
50 - 5.9 TEMPERATURE SENSORS
50 - 5.10 ENCLOSURES
51 - 5.11 SPECIFIC TESTS APPLICABLE TO ROTATING MACHINES
51 - 5.11.1 General
51 - 5.11.2 Core loss testing
52 - 5.12 SPECIFIC REQUIREMENTS FOR REPORTING ON ROTATING MACHINES
52 - 5.13 SPECIFIC REQUIREMENTS FOR PACKAGING AND DESPATCH OF ROTATING MACHINES
52 - 5.14 REINSTALLATION RECOMMENDATIONS FOR ROTATING MACHINES
53 - SECTION 6 EX 'd' FLAMEPROOF EQUIPMENT
53 - 6.1 INTRODUCTION
53 - 6.1.1 General
53 - 6.1.2 Without suffering damage
53 - 6.1.3 Without causing ignition
53 - 6.1.4 Overhaul pre-requisites
54 - 6.1.5 Initial inspection
56 - 6.2 OVERHAUL
56 - 6.3 REPAIR
56 - 6.4 RECLAMATION
56 - 6.5 CATEGORIES OF REPAIR
57 - 6.6 CHECKS AND REPORTING
57 - 6.6.1 General
57 - 6.6.2 Flameproof motors
57 - 6.6.3 Maximum surface temperature
57 - 6.6.4 Fixing bolts, studs and nuts
58 - 6.6.5 Breathing devices
58 - 6.6.6 Flamepaths
66 - 6.7 IN-SITU TEMPORARY REPAIR FOR HOLE OR THREAD
68 - 6.8 HYDROSTATIC PRESSURE TESTS
68 - 6.8.1 General
69 - 6.8.2 Testing personnel
69 - 6.8.3 Test procedure
70 - 6.8.4 Reporting of results
70 - 6.8.5 Interpretation of results
71 - 6.9 FINAL VERIFICATION
71 - 6.10 PACKAGING AND DESPATCH
72 - SECTION 7 EX 'e' INCREASED SAFETY
72 - 7.1 INTRODUCTION
72 - 7.1.1 General
72 - 7.1.2 Arcing or sparking parts
72 - 7.1.3 Insulation
72 - 7.1.4 Temperature
73 - 7.1.5 Terminals and terminations
73 - 7.2 OWNER/OPERATOR
73 - 7.3 INSPECTION/OVERHAUL
73 - 7.3.1 Insulation material
73 - 7.3.2 Insulation clearances
74 - 7.3.3 Insulation creepage
74 - 7.3.4 Physical damage
74 - 7.3.5 Temperature sensing devices
74 - 7.3.6 Terminals and terminations
74 - 7.3.7 Glands
75 - 7.3.8 Seals and IP rating
75 - 7.4 SPECIFIC ISSUES FOR ROTATING MACHINES
75 - 7.4.1 Rotor
75 - 7.4.2 Stator
76 - 7.4.3 Fans
76 - 7.4.4 Overloads
76 - 7.5 REPAIR
76 - 7.5.1 Enclosure repair
76 - 7.5.2 Winding replacement
76 - 7.5.3 Removal of windings
76 - 7.5.4 Repair of rotors
77 - 7.6 FINAL VERIFICATION
77 - 7.7 PACKAGING AND DESPATCH
77 - 7.8 REPORTING
78 - SECTION 8 EX 'i' INSTRINSIC SAFETY
78 - 8.1 GENERAL
80 - 8.2 OWNER/OPERATOR RESPONSIBILITIES
83 - 8.3 INITIAL ASSESSMENT
84 - 8.4 OVERHAUL
84 - 8.4.1 General
84 - 8.4.2 Overhaul of intrinsically safe equipment
85 - 8.4.3 Overhaul of intrinsic safety associated equipment
86 - 8.5 PASS/FAIL CRITERIA FOR OVERHAULED EQUIPMENT
86 - 8.6 COMPONENTS FORMING PART OF INTRINSICALLY SAFE EQUIPMENT
86 - 8.6.1 Enclosures
86 - 8.6.2 Cable entries
86 - 8.6.3 Terminations
86 - 8.6.4 Soldered connections
87 - 8.6.5 Fuses
87 - 8.6.6 Relays
87 - 8.6.7 Shunt diode safety barriers
87 - 8.6.8 Printed circuit boards
87 - 8.6.9 Optocouplers and piezoelectric components
87 - 8.6.10 Electrical components
88 - 8.6.11 Batteries
88 - 8.6.12 Internal wiring
88 - 8.6.13 Transformers
88 - 8.6.14 Encapsulated components
88 - 8.6.15 Non-electrical parts
88 - 8.7 TESTING/ASSESSMENT
89 - 8.8 REPAIR
89 - 8.8.1 General
89 - 8.8.2 Repairs using soldering
90 - 8.9 RECLAMATION
90 - 8.10 TESTING
90 - 8.11 ALTERATIONS AND MODIFICATIONS
90 - 8.12 REPORTING
91 - 8.13 PACKAGING AND DESPATCH
92 - SECTION 9 EX 'm' ENCAPSULATION
92 - 9.1 INTRODUCTION
92 - 9.2 REPAIR/OVERHAUL PROCEDURES
92 - 9.2.1 Removal of encapsulation material
92 - 9.2.2 Replacement of components
93 - 9.2.3 Preparation for replacing encapsulation
93 - 9.2.4 Encapsulating material
93 - 9.2.5 Pouring encapsulation material
93 - 9.2.6 Visual inspection
94 - 9.2.7 Reclamation
95 - SECTION 10 EX 'n' NON-SPARKING
95 - 10.1 INTRODUCTION
95 - 10.1.1 General
95 - 10.1.2 Arcing or sparking parts
95 - 10.1.3 Insulation
95 - 10.1.4 Temperature
96 - 10.1.5 Terminals and terminations
96 - 10.2 INSPECTION AND OVERHAUL
96 - 10.2.1 General
96 - 10.2.2 Insulation material
96 - 10.2.3 Insulation clearances
96 - 10.2.4 Insulation creepage
97 - 10.2.5 Physical damage
97 - 10.2.6 Temperature-sensing devices
97 - 10.2.7 Terminals and terminations
97 - 10.2.8 Glands
97 - 10.2.9 Seals and IP rating
98 - 10.2.10 Rubber/Neoprene type seals
98 - 10.2.11 Shaft seals
98 - 10.2.12 Equi-potential (earth) bonding
98 - 10.3 ROTATING MACHINE SPECIFIC ISSUES
98 - 10.3.1 Rotor
98 - 10.3.2 Fans
98 - 10.4 REPAIR
98 - 10.4.1 Enclosure repair
98 - 10.4.2 Winding replacement
99 - 10.4.3 Repair of rotors
99 - 10.5 FINAL VERIFICATION
99 - 10.6 PACKAGING AND DESPATCH
99 - 10.7 REPORTING
100 - SECTION 11 EX 'tD' (DIP)
100 - 11.1 INTRODUCTION
100 - 11.2 INSPECTION AND OVERHAUL
100 - 11.2.1 General
100 - 11.2.2 Gaskets
100 - 11.2.3 Motors
101 - 11.2.4 Temperature-sensing devices
101 - 11.2.5 Cables and conduit entries
101 - 11.2.6 Seals and IP rating
101 - 11.2.7 Repair
102 - 11.3 OVERHAUL
102 - 11.3.1 Motor windings
102 - 11.3.2 Repair of rotors
102 - 11.4 FINAL VERIFICATION AND TESTS
103 - 11.5 PACKAGING AND DESPATCH
103 - 11.6 REPORTING
104 - SECTION 12 EX 'p' PRESSURISED
104 - 12.1 INTRODUCTION
104 - 12.1.1 General
104 - 12.1.2 Removal from service
104 - 12.2 INITIAL INSPECTION
105 - 12.3 ENCLOSURES
105 - 12.3.1 Materials
105 - 12.3.2 Gaskets and seals
105 - 12.3.3 Fasteners
105 - 12.4 TEMPERATURE RATING
105 - 12.4.1 Lighting fittings
105 - 12.4.2 Heat-generating equipment
106 - 12.5 OVERHAUL AND REPAIR PROCEDURES FOR PRESSURISED EQUIPMENT
106 - 12.5.1 General
107 - 12.5.2 Routine tests
107 - 12.5.3 Marking
107 - 12.6 GROUP I EXPLOSION PROTECTED TRANSFORMERS
109 - SECTION 13 EX 'o' OIL FILLED
109 - 13.1 INTRODUCTION
109 - 13.2 NON-SPARKING PROTECTION
109 - 13.3 OIL CONDITIONING
109 - 13.4 TESTING
110 - SECTION 14 EX 'v' VENTILATED
111 - SECTION 15 EX 's' SPECIAL PROTECTION
112 - SECTION 16 GROUP I HAZARDOUS AREA REELING AND TRAILING CABLES
112 - 16.1 SCOPE
112 - 16.2 CABLE COMPONENTS
112 - 16.2.1 General
112 - 16.2.2 Conductors and conductor constructions
113 - 16.2.3 Insulation
113 - 16.2.4 Earthing and earthing conductors
113 - 16.2.5 Screens on the active cores
114 - 16.2.6 Semi-conductive elastomer
114 - 16.2.7 Central pilot
115 - 16.2.8 Sheath reinforcement
115 - 16.2.9 Sheath
115 - 16.2.10 Materials
117 - 16.3 GUIDANCE ON ASSESSING CABLE CONDITION
117 - 16.3.1 General
117 - 16.3.2 Initial test
117 - 16.3.3 Sheath test
117 - 16.3.4 Cable repairer
117 - 16.3.5 Final testing
117 - 16.4 EVALUATION BEFORE REPAIR AND HISTORY RECORD
117 - 16.4.1 History record
118 - 16.4.2 Cable construction
118 - 16.4.3 Terminations
119 - 16.4.4 Insulation Resistance test records
119 - 16.4.5 Symmetrical load test
119 - 16.4.6 Visual examination
119 - 16.4.7 Pre-repair tests
120 - 16.4.8 Practicability of repair
120 - 16.5 PROCEDURE FOR HARD SOLDERING REELING AND TRAILING CABLES
120 - 16.5.1 General soldering information
120 - 16.5.2 Procedure
122 - SECTION 17 PRE-OVERHAUL INSPECTION (CODE C1) FOR GROUP I
122 - 17.1 PRE-OVERHAUL REQUIREMENTS
122 - 17.2 FLAMEPROOF
122 - 17.3 INCREASED SAFETY EQUIPMENT
123 - 17.4 PRESSURISED EQUIPMENT
124 - SECTION 18 COMPLIANCE OF LEGACY PLANT
124 - 18.1 GENERAL
124 - 18.2 HISTORY
124 - 18.3 USING THE FACTS
124 - 18.4 ASSUMPTIONS
124 - 18.5 VERIFICATION DOSSIER
124 - 18.6 FACT GATHERING
124 - 18.6.1 General
126 - 18.6.2 Auditing
126 - 18.6.3 Missing information
126 - 18.6.4 Status
126 - 18.6.5 Summary
127 - APPENDIX A - QUALITY MANAGEMENT SYSTEM COMPONENT
127 - A1 GENERAL
127 - A2 ROLES AND RESPONSIBILITIES OF SERVICE FACILITY
128 - A3 QUALITY MANAGEMENT SYSTEM-RESOURCE MANAGEMENT
128 - A3.1 General
128 - A3.2 Technical library
128 - A3.3 Training and competency
129 - A4 QUALITY MANAGEMENT SYSTEM-REPORTS
130 - A5 QUALITY MANAGEMENT SYSTEM-DIMENSIONAL CHECKS
130 - A5.1 Dimensional measurements
130 - A5.2 Measuring equipment
131 - A6 QUALITY MANAGEMENT SYSTEM-WORK PROCEDURES
132 - A7 QUALITY MANAGEMENT SYSTEM-CONDITIONS FOR EQUIPMENT RELEASE
132 - A7.1 General
132 - A7.2 Welding and brazing
132 - A7.3 Non-conforming product
133 - APPENDIX B - MEASUREMENT AND CALIBRATION IN Ex WORKSHOPS
133 - B1 SUMMARY-ESSENTIAL WORKSHOP INFORMATION
133 - B2 WORKSHOP MEASUREMENT MANAGEMENT
133 - B3 CALIBRATION INTERVALS
134 - B4 CONTEXT
135 - B5 DEFINITIONS
135 - B5.1 Calibration
135 - B5.2 Traceability
135 - B5.3 Verification
135 - B6 SPECIFYING MEASUREMENTS
135 - B6.1 General
136 - B6.2 The metric system, calibration and traceability
137 - B7 CALIBRATION PATHWAYS FOR TRACEABILITY
137 - B7.1 General
138 - B7.2 Pathway A
138 - B7.3 Pathway B
139 - B7.4 Pathway C
139 - B7.5 Implementation of pathways
139 - B8 PERFORMANCE BREAKDOWN AND RE-CALIBRATION
141 - B9 CALIBRATION OF COMMONLY USED EQUIPMENT
141 - B9.1 General
141 - B9.2 Specifications for calibration
141 - B9.3 Considerations in purchasing calibration services
141 - B9.4 Outsourcing of verification activities
142 - B10 EFFECTS OF UNCERTAINTY ON CONFORMITY DECISIONS
142 - B10.1 General
144 - B10.2 Assumptions
144 - B11 MEASUREMENT CONSIDERATIONS
144 - B11.1 General
145 - B11.2 Analysis of measurement tasks
145 - B11.3 Considerations
145 - B11.4 Selection of measuring equipment
145 - B11.5 Use of user-adjustable equipment (zero and span)
146 - B11.6 Application of correction factors
146 - B11.7 Environmental influences
146 - B11.8 Environmental monitoring equipment
146 - B11.9 Use of hired equipment
147 - B11.10 Determination of calibration intervals
148 - B12 EQUIPMENT ASSURANCE PROGRAMS
148 - B12.1 General
148 - B12.2 Suspending calibration or checks
148 - B12.3 Integration of calibration activities with workshop measurement
149 - B13 COMMENTARY ON MEASUREMENT TASKS
149 - B13.1 General
149 - B13.2 Length
149 - B13.3 Surface roughness
149 - B13.4 Thread gauges
149 - B13.5 Torque
149 - B13.6 Electrical
149 - B13.7 Temperature
149 - B13.8 Balancing
150 - B13.9 Pressure testing
150 - B14 COMMENTARY UPON MP 87-2
150 - B15 EQUIPMENT RECORD KEEPING
151 - B16 REFERENCES
155 - APPENDIX C - SAMPLE CERTIFICATES AND FORMS
192 - APPENDIX D - HISTORICAL INFORMATION RELATING TO EQUIPMENT APPROVAL SCHEMES
192 - D1 GENERAL
192 - D2 STATE AUTHORITY APPROVALS
192 - D2.1 History
193 - D2.2 Overview
193 - D2.3 Handling changes
193 - D3 P/3 APPROVALS COMMITTEE (1960–1987)
193 - D3.1 History
193 - D3.2 Overview
194 - D4 P/3 AUSEx SCHEME (1987–1993)
194 - D5 AUSEx SCHEME 1993–2003
194 - D5.1 History and overview
194 - D5.2 Documentation
195 - D6 ANZEx SCHEME 2001
195 - D7 HANDLING CHANGES
196 - D8 RELEVANT INTERNATIONAL SCHEMES
196 - D8.1 UK
196 - D8.2 IECEx
197 - APPENDIX E - HISTORICAL INFORMATION RELATING TO SERVICE FACILITY APPROVAL SCHEMES

The objective of this Handbook is to provide service facilities, equipment owner and/or operators and relevant regulatory authorities involved in the repair and overhaul of electrical equipment in hazardous areas with guidance to ensure safety and compliance with the relevant existing Standards. The Handbook also offers additional guidance on techniques and special processes necessary to ensure consistent and reliable delivery of repaired and overhauled equipment and cables.

This Handbook provides guidance for the repair and overhaul of explosion-protected electrical equipment used in hazardous areas (defined in AS/NZS 60079.0).The Handbook covers equipment with a Group I designation for coal mining; Group II where flammable gases and vapours may be present; and Group III which includes equipment used in the presence of combustible dusts. This Handbook details the methods of overhaul, repair, examination and the testing required to ensure safety and compliance with the relevant Standards for the different equipment explosion-protection techniques. It covers the several types of explosion-protection techniques currently in use and provides guidance for repair and overhaul service facilities.The soon to be published revision of AS/NZS 3800 (and IEC 60079-19 Edition 3) offer a performance-based approach to the overhaul of electrical equipment for use in hazardous areas. In many applications it was felt it was necessary to establish guidance to standardise the approach for inspection, repair and overhaul techniques and methods, and to provide a repository where expert knowledge can be accumulated from experience and disseminated for the benefit of stakeholders.The objective of this Handbook is to provide service facilities, equipment owner and/or operators and relevant regulatory authorities involved in the repair and overhaul of electrical equipment in hazardous areas with guidance to ensure safety and compliance with the relevant existing Standards.The Handbook also offers additional guidance on techniques and special processes necessary to ensure consistent and reliable delivery of repaired and overhauled equipment and cables.This document is to be read initially in conjunction with AS/NZS 3800 and IEC 60079-19 Edition 3, the recognized international Standard for repair and overhaul of explosion-protected electrical equipment. In anticipation of the soon-to-be published revised AS/NZS 3800 (and IEC 60079 Edition 3), where possible, reference to these documents has been quoted throughout the text.

First published as HB 239:2011.