Standard
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AS/NZS 5368:2025
[Current]Electrical equipment in mines and quarries
AS/NZS 5368:2025 sets out requirements and recommendations for the design, installation, and operation of electrical equipment in mines and quarries to ensure the safety of persons, livestock and property, and the proper functioning of plant.
Published: 27/06/2025
Pages: 200
Table of contents
Cited references
Content history
Table of contents
Header
About this publication
Preface
1 Scope and general
1.1 Scope
1.2 Application
1.2.1 General
1.2.2 General requirements
1.2.3 Requirements for fixed equipment and installations
1.2.4 Requirements for transportable and mobile plant and equipment
1.2.5 Requirements for electrical equipment located in hazardous areas
1.2.6 Relationship with other industry standards
1.3 Normative references
1.4 Terms and definitions
1.5 Equipment life cycle
1.6 Risk management
1.7 Change management
1.8 Safe work locations
1.8.1 General
1.8.2 Controlled work area
1.8.3 No standing zone
1.8.4 No entry zone
1.8.5 Remote-controlled equipment
1.8.6 Autonomous equipment
1.8.7 Proximity detection
1.8.8 Proximity awareness
1.8.8.1 Travel alarm
1.8.8.2 Pre-start alarms
1.9 Power system design
1.9.1 General
1.9.2 Earthing
1.9.2.1 General
1.9.2.1.1 Earthing protection system
1.9.2.1.2 Supply system
1.9.2.1.3 Earth fault current limitation
1.9.2.2 Neutral earthing conductor to NER
1.9.3 Protection
1.9.3.1 General
1.9.3.2 Protection methods
1.9.3.2.1 Short-circuit protection
1.9.3.2.2 Overload protection
1.9.3.2.3 Coordination of overload and short-circuit protection afforded by separate devices
1.9.3.2.4 Undervoltage protection
1.9.3.2.5 Loss of vacuum/frozen contact protection
1.9.3.2.6 Under/overpressure protection
1.9.3.2.7 Overtemperature protection
1.9.3.2.8 Earth fault protection systems
1.9.3.2.8.1 Earth continuity protection
1.9.3.2.8.2 Earth leakage protection
1.9.3.2.8.3 Earth fault lockout protection
1.9.3.2.8.4 Earth fault current limitation device integrity
1.9.3.2.8.5 Earth fault protection
1.9.3.3 Self-powered protection devices
1.9.3.4 Substation primary protection
1.9.3.5 Motor protection
1.9.3.6 Control, protection or auxiliary circuits
1.9.3.7 Unprotected ELV circuits of diesel-powered machinery and ancillary equipment
1.9.3.8 Power alternator or generator speed limitation
1.9.4 Harmonic sources
1.9.5 Emergency stop devices and associated circuitry
1.10 Equipment design and installation
1.10.1 General
1.10.1.1 Assembly
1.10.2 Earthing
1.10.2.1 Connection facilities for earthing and equipotential bonding conductors
1.10.2.2 Cables containing only analogue and/or digital signals
1.10.2.3 Circuits requiring earthing for access
1.10.2.3.1 General
1.10.2.3.2 Verification of contacts
1.10.3 Design and manufacture
1.10.3.1 Design and selection
1.10.3.2 Arc blast protection
1.10.3.3 Isolation and devices
1.10.3.3.1 General requirements
1.10.3.3.2 Isolation and devices
1.10.3.3.3 Removal of power at a closed electrical operating area
1.10.3.3.4 Electrical isolation
1.10.3.3.5 Isolating for non-electrical tasks
1.10.3.3.6 Remote isolation systems
1.10.3.3.7 Battery isolator
1.10.3.3.7.1 General
1.10.3.3.7.2 Auxiliary/starter isolator
1.10.3.4 Extra low voltage alternators
1.10.3.4.1 Cable rating
1.10.3.4.2 Cable protection
1.10.3.4.2.1 General
1.10.3.4.2.2 Short-circuit protection
1.10.3.4.2.3 Overload protection
1.10.3.5 Enclosure requirements
1.10.3.5.1 General
1.10.3.5.2 Location of protection device indicators
1.10.3.5.3 Operator controls
1.10.3.5.4 Internal segregation
1.10.3.6 Lighting
1.10.3.7 Terminations external to an enclosure
1.10.3.8 Withdrawable and plug-in equipment
1.10.3.9 Interlocking
1.10.3.9.1 General requirements
1.10.3.9.2 Interlocking methods
1.10.3.9.3 Electrical interlocking of restrained plugs
1.10.3.9.4 Electrical interlocking of enclosures containing stored energy
1.10.3.10 Positioning of outlets
1.10.3.10.1 General
1.10.3.10.2 Thermography
1.10.3.11 Component requirements — Creepage and clearance
1.10.3.12 Switching devices
1.10.3.12.1 General
1.10.3.12.2 Isolating switches
1.10.3.12.3 Circuit-breakers
1.10.3.12.4 Low voltage distribution board circuit-breakers
1.10.3.12.5 High voltage switchgear assembly
1.10.3.12.6 Combined fuse switch (CFS) unit
1.10.3.12.7 Contactors
1.10.3.13 Measuring instruments
1.10.3.14 Transformers
1.10.3.14.1 General
1.10.3.14.2 Power transformers
1.10.3.14.3 Control transformers
1.10.3.15 Protection and instrumentation transformers
1.10.3.16 Rotating electrical machines
1.10.3.16.1 Mechanical construction
1.10.3.16.2 Guarding
1.10.3.16.3 Features
1.10.3.16.4 Synchronous motors
1.10.3.17 Control circuits and devices
1.10.3.17.1 General
1.10.3.17.2 Hold-to-run control
1.10.3.17.3 Start controls
1.10.3.17.4 Stop controls
1.10.3.18 Variable speed drives
1.10.3.19 Electronic/programmable electronic based systems
1.10.3.19.1 General
1.10.3.19.2 Software
1.10.3.19.3 Hardware
1.10.3.19.4 Isolation of data and communications lines
1.10.3.19.5 EMC immunity and emissions
1.10.3.20 Remote control
1.10.4 Cabling and control requirements
1.10.4.1 Cables
1.10.4.2 Single-core cables
1.10.4.3 Installation of cables and couplers
1.10.4.4 Conductor insulation
1.10.4.5 Protective earthing conductors
1.10.4.6 Power conductors
1.10.4.7 Auxiliary conductors
1.10.4.8 Internal wiring
1.10.4.9 Cable connectors for diesel-powered machinery and ancillary equipment
1.10.4.10 Distribution cables
1.10.5 Fire detection and protection for electrical areas
1.10.5.1 General
1.10.5.2 Analysis of need for protection
1.10.5.3 Means of protection
1.10.5.3.1 Protection by means of escape
1.10.5.3.2 Protection by portable means
1.10.5.3.3 Protection by means of barriers and/or enclosures
1.10.5.3.4 Protection by manually activated systems
1.10.5.3.5 Protection by automatically activated systems
1.10.5.3.6 Fixed detection, alarm and fire extinguishing systems and their equipment
1.10.5.3.7 Quantity and type of fire extinguishing medium available
1.10.5.4 Additional requirements and recommendations
1.10.5.4.1 Fire protection notices
1.10.5.4.2 Protection of equipment or plant
1.10.5.4.3 De-energization of electrical equipment
1.10.5.4.4 Supplementary fire extinguishing equipment
1.10.5.4.5 Maintenance of fire protection systems
1.10.5.4.6 Ventilation systems and air conditioners
1.10.6 Labels and signage
1.10.6.1 General
1.10.6.2 Component marking
1.10.6.3 Wiring marking
1.10.6.4 Safety signs and labels
1.10.6.5 Rating plate
1.10.6.6 Site specific requirements
1.10.6.7 Voltage identification of electrical enclosures
1.10.7 Safety critical plant
1.10.7.1 Safety critical electrical systems
1.10.7.1.1 General
1.10.7.1.2 Risk assessment
1.10.7.2 Continuity of the electrical supply at an underground mine
1.10.7.3 Continuity of supply to the underground workings containing safety critical plant
1.10.7.3.1 Distribution network design
1.10.7.3.2 Sustaining network supplies in the event of disruption
1.10.8 Specific power supplies
1.10.8.1 Switch mode power supplies
1.10.8.2 Self-contained power systems
1.10.8.3 Welding machines and equipment
1.10.8.4 Inverters and uninterruptible power supplies
1.10.8.4.1 General
1.10.8.4.2 Inverters
1.10.8.4.3 Uninterruptible power supplies
1.10.9 Redundant plant
1.10.10 Blasting near electrical assets
1.11 Testing
1.11.1 General
1.11.2 Modification of type tested equipment
1.11.3 Testing of devices and self-contained components incorporated in the assembly
1.12 Operational requirements
1.12.1 General
1.12.2 Information requirements
1.12.3 Oil filled electrical equipment
1.12.4 Restrictions on access by personnel
1.12.4.1 Identification of closed electrical operating areas
1.12.4.2 Access to closed electrical operating areas
1.12.5 Personnel working on or near exposed live parts
1.12.5.1 Low voltage
1.12.5.2 High voltage
1.12.6 Battery charging
1.12.7 Static electricity
1.12.7.1 Static electricity
1.12.7.2 Electrostatic precipitators
1.12.8 Hazards from electrical coupling
1.12.9 Radioactive sources
1.13 Documentation
1.13.1 Plant safety file (verification dossier)
1.13.2 Technical maintenance and operational manuals
1.13.3 Manuals and supporting documentation
2 Fixed equipment and installations
2.1 Overhead lines
2.1.1 General
2.1.2 Easements and corridors
2.1.3 Mine owned/operated OHLs
2.1.3.1 Placement of OHLs
2.1.3.2 Other design considerations
2.1.4 Work near OHLs
2.1.4.1 General
2.1.4.2 Clearance to mobile plant
2.1.4.2.1 Risk assessment
2.1.4.2.2 Horizontal clearances
2.1.4.3 Clearances to hand-held objects
2.1.4.4 Clearance to excavations
2.1.4.5 Clearance to blasting operations
2.1.4.6 Clearance to stockpile and tailing areas
2.1.4.7 Clearance to storage areas
2.1.4.8 Clearance to structures and people transit areas
2.1.4.9 Reduction of clearances
2.1.5 Decommissioning overhead lines
2.1.6 Moving of OHLs
2.1.7 Precautions during lightning storms
2.1.8 Operations involving long metallic structures
2.1.9 Clearing vegetation near OHLs
2.1.10 Emergency response plan for contact with OHLs
2.2 Conveyors — Fixed
2.2.1 General provisions for conveyors
2.2.2 Belt splicing equipment
2.3 Gas drainage plant
2.4 Coal mine reclaim tunnels
2.4.1 General
2.4.2 Automatic gas monitoring system
2.4.2.1 Explosive atmospheres
2.4.2.2 Irrespirable gasses
2.4.2.3 Reclaim or transfer tunnel shutdown
2.4.3 Reclaim or transfer tunnel emergency lighting
2.4.4 Stockpiles above reclaim or transfer tunnels
2.5 Powered winding systems
2.5.1 Availability of exits from the mine
2.5.2 Gravity winding
2.5.3 Testing of auxiliary pony drive and gravity winding systems
2.5.4 Diesel-driven emergency generators
3 Transportable and mobile plant and equipment
3.1 Safety systems
3.1.1 Warning devices
3.1.2 Plant shutdown
3.2 Mobile machines
3.2.1 Isolation for electrical access
3.2.2 Automatic gas monitoring system
3.2.3 Electrical braking
3.3 Battery powered equipment
3.3.1 General
3.3.2 Lithium batteries
3.3.3 Battery container design
3.3.4 Electrical protection
3.3.5 Enclosure interlocking
3.3.6 Battery cells
3.3.6.1 General
3.3.6.2 Connections
3.3.6.3 Duty
3.3.7 Battery switching device
3.4 Machine controls
3.4.1 Dual operating stations
3.4.2 Machine interconnection
3.4.3 Emergency stop device
3.5 Machine interlocks
3.5.1 General
3.5.2 Doors
3.5.3 Water flow
3.5.4 Roof bolting
3.5.5 Control mode
3.5.6 Conveyor reversing
3.5.7 Cable interlock
3.5.8 Pilot control
3.6 Marking and labelling
3.6.1 Battery isolator
3.6.2 Jump-start receptacle
3.7 Mobile machinery lighting systems
3.8 Protection of cables and cable harness
3.8.1 General
3.9 Restraint of cables and cable harnesses
3.10 Circuits utilizing machine frame
3.11 Transportable/mobile substations
3.11.1 Transportable substations
3.11.1.1 Earthing terminals
3.11.1.2 Equipotential bonding
3.11.1.3 Control enclosures
3.11.1.4 Positioning of outlets
3.11.2 Transportable buildings and IT earthing systems
3.11.2.1 General
3.12 Trailing, reeling and feeder cables
3.12.1 Cable requirements
3.12.1.1 General
3.12.1.2 Protective earthing conductor
3.12.1.3 Armouring as protective earthing conductor
3.12.1.4 Semi-conducting layers
3.12.1.5 Provision of screens and/or armouring for cables above 1 000 V
3.12.1.6 Segregation of power and control cores
3.12.1.7 Power cable twist limitation
3.12.1.8 Cable connectors
3.12.2 Moving cables
3.12.2.1 Cable management plan
3.12.2.2 Cable damage prevention
3.12.3 Installation of cables
3.12.3.1 Protection of cables
3.12.3.2 Cable roadways
3.12.3.3 Anchoring of cables
3.12.3.4 Relocating of cables
3.12.4 Cable towers and high wall gantries
3.12.4.1 Cable towers
3.12.4.2 Cable gantries
3.12.5 Manual handling of cable couplers
3.12.6 Additional protection requirements for trailing cables
3.12.7 Cable repair
3.12.8 Precautions during lightning storms
3.12.9 Cable termination boxes
3.12.10 Reeling and trailing cable attachments
3.13 Cable reels
3.13.1 General
3.13.2 Cable rating factors
3.13.3 Cable reel bearings
3.13.4 Cable reel dimensions
3.13.5 Cable reel interlock limit
3.14 Conveyors
3.14.1 General
3.14.2 Cables of conveyors
3.15 Underground high voltage section isolators
3.15.1 General
3.15.2 Isolation and indication
3.15.3 Positioning of outlets
3.16 Distribution control boxes
3.16.1 General
3.16.2 Positioning of outlets
3.16.3 Lighting
3.17 Underground ventilation fans
3.18 Underground coal fire protected diesel vehicles
3.18.1 General
3.18.2 General arrangement, control and protection
3.18.2.1 Electrical equipment ingress protection
3.18.2.2 Battery isolator
3.18.2.3 Connections to frame
3.18.2.4 Alternators
3.18.2.5 Electrical power outlets
3.18.2.6 Cables
3.18.3 Engine safety shutdown system
3.18.3.1 General
3.18.3.2 Methane monitoring system
3.18.3.3 Zone safety control system
3.18.4 Electrical protection
3.18.5 Alternator voltage regulation
3.18.6 Type of cable and conductors
3.18.7 Cables for engine safety shutdown systems
3.18.7.1 Marking and identification
3.18.7.2 Protection of cabling systems
3.18.7.3 Segregation of cabling systems
3.19 Underground coal flameproof diesel vehicles
3.19.1 Methane monitoring system
3.19.1.1 General
3.19.1.2 Design
3.19.1.3 Manufacture
3.19.1.4 Methane monitoring system operation
4 Electrical equipment located in hazardous areas
4.1 Aluminium or light metal alloy parts
4.2 Protection
4.2.1 Earth leakage protection
4.2.2 Interlocking
4.2.2.1 General
4.2.2.2 Electrical interlocking
4.2.3 Pilot protection of restrained receptacles
4.2.4 Earth fault lockout
4.2.5 Earth continuity and earth fault lockout protection
4.3 Enclosures
4.3.1 Explosion-protected enclosures
4.3.2 Isolation
4.3.3 Stored energy devices other than batteries
4.3.4 High-energy arcing faults
4.3.5 Surface temperature
4.4 Batteries and energy storage devices
4.5 Cable protection
4.6 Machine cables
4.6.1 General
4.6.2 Intrinsically safe cables
4.6.2.1 General
4.6.2.2 Intrinsically safe conductors
4.6.3 Light alloy screening
4.7 Battery powered mobile machines — Connections to the battery
4.8 Hazardous area ventilation fans installed underground
4.9 Power supplies to de-watering and methane drainage plant and equipment
Appendix A
A.1 Safety file
A.2 Proprietary information
Appendix B
B.1 General
B.2 Underground mines (coal and metals)
B.3 Underground coal mines
Appendix C
C.1 General
C.2 Examples
C.2.1 General
C.2.2 Example 1
C.2.2.1 General
C.2.2.2 Example 1a
C.2.2.3 Example 1b
C.2.3 Example 2
C.2.3.1 General
C.2.3.2 Example 2a
C.2.3.3 Example 2b
C.3 Calculation of prospective touch voltage
Appendix D
D.1 General
D.2 Description of the systems
D.3 Protective measures for TN systems
D.3.1 General
D.3.2 Bonding of exposed conductive parts
D.3.2.1 General
D.3.2.2 Single conductor as combined protective and neutral conductor
D.3.2.3 Interruption of combined protective and neutral conductor
D.3.2.4 Separation of protective conductor from a combined protective and neutral conductor
D.4 Protective measures for TT systems
D.4.1 General
D.4.2 Neutral conductor for insulation and installation
D.4.3 Bonding of exposed conductive parts
D.4.4 Protective devices
D.5 Protective measures for IT systems
D.5.1 General
D.5.2 Artificial earthable point
D.5.3 Star point conductor in IT systems
D.5.4 Bonding of exposed conductive parts
D.5.5 Protective devices
D.5.6 Neutral conductor in IT systems
Appendix E
E.1 General
E.2 Voltage rating of equipment connected to an earth fault current limited circuit
Appendix F
F.1 Selection of protective devices and protection systems
F.1.1 Introduction
F.1.2 Operating characteristics
F.1.3 Interposing relays in protection systems
F.1.4 Discrimination between protective devices
F.2 Protective devices
F.2.1 General
F.2.2 Measuring transformers
F.2.3 Residual-current-operated protective devices
F.2.4 Residual-voltage-operated protective devices
F.2.5 Fault-voltage-operated protective devices
F.2.6 Combined residual-current/voltage-operated protective devices
F.2.7 Insulation monitoring devices
F.2.8 Distance relays
F.2.9 Differential protection
F.2.10 Overcurrent-operated protective devices
F.2.10.1 General
F.2.10.2 Thermal overload ANSI code 49 RMS
F.2.10.3 Phase overcurrent ANSI code 50/51
F.2.11 Loss of vacuum/frozen contact protection devices
F.2.12 Under/overpressure protection devices
F.2.13 Earth continuity protection devices
F.2.14 Earth leakage protection
F.2.15 Earth fault lockout protection
F.2.16 Neutral-connected current limitation system integrity protection
F.2.17 Undervoltage ANSI code 27/27S
F.2.18 Positive sequence undervoltage ANSI code 27D
F.2.19 Phase rotation direction check ANSI code 27D/47
F.2.20 Remanent undervoltage ANSI code 27R
F.2.21 Directional active overpower ANSI code 32P
F.2.22 Directional reactive overpower ANSI code 32Q/40
F.2.23 Phase undercurrent ANSI code 37
F.2.24 Temperature monitoring ANSI code 38/49T
F.2.25 Negative sequence/unbalance ANSI code 46
F.2.26 Broken conductor ANSI code 46BC
F.2.27 Negative sequence overvoltage ANSI code 47
F.2.28 Excessive starting time locked rotor ANSI code 48/51LR/14
F.2.29 Breaker failure ANSI code 50BF
F.2.30 Earth fault ANSI code 50N/51N or 50G/51G
F.2.31 Starts per hour ANSI code 66
F.2.32 Directional overcurrent (67) and directional earth fault (67N)
F.2.33 Neutral voltage displacement (59N)
F.2.34 Volt/hertz (24)
F.2.35 Bus overcurrent blocking schemes
F.3 Protection arrangements for transportable substations
F.4 Testing of power system protection system
F.4.1 General
F.4.2 Electromechanical relays
F.4.3 Digital and numerical relays
Appendix G
G.1 General
G.2 Component mounting
Appendix H
H.1 General
H.2 Auxiliary components
H.3 Explosion protection
Appendix I
I.1 General
I.2 Test facility
Appendix J
Appendix K
Appendix L
L.1 Introduction
L.2 Assessment of general characteristics
L.3 Protection of persons against the transfer of unsafe voltages
L.3.1 Causes of voltage transfer
L.3.2 Measures for protecting persons against direct transfer of unsafe voltages
L.3.3 Measures for protecting persons against indirect transfer of unsafe voltages
L.4 Protection of low signal level systems against malfunction due to interference
L.4.1 Basic principle
L.4.2 Protection measures
L.4.2.1 Design features
L.4.2.2 Other measures
L.4.3 Transmission by cable
L.4.3.1 Screening against capacitive (electrostatic) interference
L.4.3.2 Shielding against inductive (electromagnetic) interference
L.4.3.3 Physical separation from power cables and equipment
L.4.3.4 Segregation of circuits
L.4.3.5 Transmission by powerline carrier
L.4.4 Transmission by radio
L.4.4.1 Safety precautions relating to the use of radio
L.4.4.2 Physical isolation of sensitive elements
Appendix M
M.1 General
M.2 Key issues concerning the VSD output voltage
Appendix N
N.1 Relating to the installed electrical system
N.2 Electrical equipment requirements
N.3 Relating to cables and cable entries
Appendix O
O.1 General
O.2 Recommended process
O.3 Other recommendations
Appendix P
Appendix Q
Q.1 General
Q.2 Methods of verifying compliance
Q.2.1 General
Q.2.2 Combination of type and/or routine testing
Q.2.3 Comparison to a reference design by professional engineering assessment
Q.2.4 Professional engineering assessment
Q.3 Verification of characteristics
Appendix R
Appendix S
S.1 Risk management
S.2 Process
S.3 Safety-related control function
S.4 Functional safety techniques
Appendix T
Appendix U
Appendix V
Bibliography
Cited references in this standard
Content history
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