PART XX ELECTRICITY
|Selection and installation of apparatus
20.1 The mine manager shall take such steps as may be necessary to ensure that any :-
(a) - electrical apparatus used in connection with the working of a mine is of suitable design, sound construction, suitable material, free from any defects, properly maintained and protected in such a manner that no person can be injured by inadvertent contact with any live portion;
(b) - place where electrical apparatus is installed and which may constitute danger to persons is adequately fenced off or effectively enclosed.
The mine manager shall ensure that :-
Electrical control gear
20.2 (1) (a) - any electrical installation and power line is provided with adequate protective devices and controlling apparatus which shall, as far as is practicable, automatically isolate the power supply in the event of a fault developing on such installation or power line;
(b) - switchgear is designed that it cannot be closed accidentally by gravity, impact or any other cause and is provided with a cover to prevent accidental contact with live parts;
(c) - any controlling apparatus is marked or labelled prominently so as to identify the system or part of the system or the electrical machinery which it controls.
(d) - whenever work is to be carried out on electrical apparatus which has been isolated from all sources of supply and locked out, effective precautions are taken to electrically discharge such apparatus and any other electrical apparatus which may be interlinked by earthing or other means before it is handled to prevent any conductor or apparatus from being made live accidentally or inadvertently while any person is working thereon.
(2) No person shall interfere with or render ineffective any protective device.
Diagrams of electrical equipment
20.3 - schematic diagrams showing the up-to-date position of all permanent high tension electrical equipment are kept.
Posting of notices
20.4 (1) - at places where electrical apparatus is installed which may constitute a danger to persons, notices are prominently displayed -
(a) prohibiting any unauthorized person from entering, handling or interfering with apparatus;
(b) containing directions as to the procedure to be followed in case of fire;
(c) containing directions on the rescue and first aid treatment of persons suffering from electric shock or burns.
(2) Any person working with electrical equipment shall acquaint himself or herself with the notices posted under subregulation (1) and shall act in accordance with the directions therein.
Switch and transformer premises
20.5 (a) - any enclosed premises housing switchgear and transformers are-
(i) of adequate size so as to provide safe working space for operating and maintenance staff;
(ii) constructed in such a manner that persons cannot reach in and touch bare conductors or exposed live parts of the electrical machinery;
(iii) sufficiently ventilated to maintain the equipment at a safe working temperature;
(iv) where necessary, provided with lighting that will enable all equipment, thoroughfares and working areas to be clearly distinguished and all instruments, labels and notices to be easily read;
(v) provided with unobstructed doors or gates which open outwards;
(vi) as far as is practicable, constructed so as to be proof against rodents, leakage, seepage and flooding.
(b) - no person other than an authorized person enters premises housing switchgear or transformers.
Scheme for installation and use of electrical apparatus
20.6 (1) The mine manager shall formulate a scheme with respect to the installation, re-installation and use of electrical apparatus at the mine.
(2) The scheme referred to in subregulation (1) shall include provisions concerning the :-
(a) - examination and testing of all electrical equipment before it is energized after installation or re-installation;
(b) - systematic examination and testing of all electrical apparatus to ensure proper maintenance thereof;
(c) - nature of the examination and testing to be carried out;
(d) - procedure to be followed and precautions to be taken to ensure the safety of persons working on electrical apparatus; and
(e) - identification of installations and the recording of the results of examinations and tests.
20.7 (a) - any accessible metallic portion of electric plant or apparatus which, though not normally forming part of an electrical circuit, may accidentally become live, is either protected by insulating material or is connected to earth by a conductor of adequate cross-sectional area so as to prevent danger to persons;
(b) - the cross-sectional area of any earthing conductor is calculated to be capable of withstanding the maximum possible earth fault current condition.
Earth leakage protection
20.8 (a) - a suitable method of earth leakage protection is, as far as is practicable, provided for all alternating current circuits operating above extra low voltage;
(b) - earth leakage protection equipment is provided with means by which tests of its operation may be made;
(c) - earth leakage protection equipment is rated for operation at not more than 300 Mega ampere.
Lightning and surge protection
20.9 -suitable equipment is provided to protect any electrical installation from abnormal voltage due to atmospheric electric discharges and switching surges.
20.10 (a) - any cable is properly placed, attached, connected and supported;
(b) - the covering of an electric cable is -
(i) in the form of tape or tube enclosing one or more conductors to provide adequate mechanical protection;
(ii) continuous throughout;
(iii) securely attached to the apparatus to which such cable is connected;
(iv) suitably bonded at junctions.
Flexible cable or trailing cable
20.11 (a) -only a flexible cable or trailing cable is used in connection with the operation of
(i) any self-propelled mobile machine;
(ii) movable electrical apparatus;
(iii) portable electrical apparatus;
(b) that any flexible cable or trailing cable is screened, where necessary, and such screens are earthed;
(c) that, when blasting is to be carried out, cables are suitably protected from damage or be removed from the site prior to blasting;
(d) that at any point where any flexible cable is joined to a main cable, a switch is provided to cut off the current from the flexible cable.
Signal and telephone cables
20.12 -signal and telephone cables are not allowed to come into electrical contact with each other or with any other electrical conductor.
Operation of electrical apparatus
20.13 (1) - no person operates any electrical apparatus, unless he or she has been instructed in its use and has been duly authorized to do so.
(2) A person who operates a portable electrical machine shall -
(a) carefully inspect the machine and the flexible cable attached thereto prior to operating the machine;
(b) on observing any defect shall not start the machine until the defect has been rectified; and
(c) satisfy himself or herself that the electric current is cut off from the flexible cable and machine before leaving the workplace.
(3) The mine manager shall take such steps as may be necessary to ensure
(a) - current is switched off from all conductors and apparatus which are not in use;
(b) - no work is undertaken on any live conductor or live part of apparatus: provided that where the apparatus must be live for the purpose of examination, adjustment, testing, repair or other work, such work may only be undertaken by a person duly authorized to do so;
(c) - any insulating material is suitable for the purpose for which it is used;
(d) - provision is made to confine safely any oil or other fluid which may escape from electrical apparatus;
(e) - as far as is practicable, no metal ladder or ladder with metal reinforced tiles may be used for examination, repair or other work necessitating dangerous approach to or work on electrical apparatus.
(f) - no object is brought closer to a live power line than the distance specified in the following table -
Voltage of power line Minimum clearance
up to 250 kilovolts 2 meters
251 to 400 kilovolts 3 meters
above 400 kilovolts 4 meters
(4) Any person employed in or at a mine shall immediately report overheating, arcing, electrical shock or damage relating to any electrical installation or apparatus which may come to his or her knowledge.
Precautions in explosive or flammable atmosphere
20.14 The mine manager shall, where explosive or flammable atmosphere is encountered, adopt such precautions, apparatus and methods of installation as may be specified by the Chief Inspector.