HK Cap. 107C — Use of Electric Power on the Tramway Rules

Use of Electric Power on the Tramway Rules ( Cap. 107, sections 31 and 34 ) [14 May 1902] (Format changes— E.R. 3 of 2021 ) 1. These rules may be cited as the Use of Electric Power on the Tramway Rules. 2. In the following rules, unless the context otherwise requires— current ( 電流 ) means an electric current exceeding one-thousandth part of one ampere; energy ( 能量 ) means electrical energy; generator ( 發電機 ) means the dynamo or dynamos or other electrical apparatus used for the generation of energy; motor ( 發動機 ) means any electric motor carried on a car and used for the conversion of energy; pipe ( 喉管 ) means any gas or water pipe, or other metallic pipe, structure or substance; wire ( 電線 ) means any wire or apparatus used for telegraphic, telephonic, electrical signalling or other similar purposes. 3. Any dynamo used as a generator shall be of such pattern and construction as to be capable of producing a continuous current without appreciable pulsation. 4. One of the two conductors used for transmitting energy from the generator to the motors shall be in every case insulated from earth, and is hereinafter referred to as the line ; the other may be insulated throughout or may be uninsulated in such parts and to such extent as is provided in the following rules, and is hereinafter referred to as the return . 5. Where any rails on which cars run, or any conductors laid between or within 1 m of such rails, form any part of a return such part may be uninsulated. All other returns or parts of a return shall be insulated, unless of such sectional area as will reduce the difference of potential between the ends of the uninsulated portion of the return below the limit laid down in rule 9 . ( L.N. 156 of 1977 ) 6. When any uninsulated conductor laid between or within 1 m of the rails forms any part of a return, it shall be electrically connected to the rails at distances apart not exceeding 30 m by means of copper strips having a sectional area of at least 40 mm², or by other means of equal conductivity. ( L.N. 156 of 1977 ) 7. When any part of a return is uninsulated it shall be connected with the negative terminal of the generator, and in such case the negative terminal of the generator shall also be directly connected, through the current indicator hereinafter mentioned, to two separate earth connexions which shall be placed not less than 20 m apart: Provided that in place of such two earth connexions the company may make one connexion to a main for water supply of not less than 75 mm internal diameter, with the consent of the owner thereof and of the person supplying the water, and provided that where, from the nature of the soil or for other reasons, the company can show to the satisfaction of an inspecting officer of the Government that the earth connexions herein specified cannot be constructed and maintained without undue expense, the provisions of this rule shall not apply. The earth connexions referred to in this rule shall be constructed, laid and maintained so as to secure electrical contact with the general mass of earth, and so that an electro-motive force not exceeding four volts shall suffice to produce a current of at least two amperes from one earth connexion to the other through the earth, and a test shall be made at least once in every month to ascertain whether this requirement is complied with. No portion of either earth connexion shall be placed within 2 m of any pipe except a main for water supply of not less than 75 mm internal diameter metallically connected to the earth connexions with the consents hereinbefore specified. ( L.N. 156 of 1977 ) 8. When the return is partly or entirely uninsulated the company shall in the construction and maintenance of the tramway— (a) so separate the uninsulated return from the general mass of earth and from any pipe in the vicinity; (b) so connect together the several lengths of the rails; (c) adopt such means for reducing the difference produced by the current between the potential of the uninsulated return at any other point; and (d) so maintain the efficiency of the earth connexions specified in the preceding rules, as to fulfil the following conditions— (i) that the current passing from the earth connexions through the indicator to the generator shall not at any time exceed either 1.2 A/km of single tramway line, or five per cent of the total current output of the station; ( L.N. 156 of 1977 ) (ii) that if at any time and at any place a test be made by connecting a galvanometer or other current-indicator to the uninsulated return to any pipe in the vicinity, it shall always be possible to reverse the direction of any current indicated by interposing a battery of three Leclanché cells connected in series if the direction of the current is from the return to the pipe, or by interposing one Leclanché cell if the direction of the current is from the pipe to the return. In order to provide a continuous indication that condition (i) is complied with, the company shall place in a conspicuous position a suitable properly connected and correctly marked current-indicator and shall keep it connected during the whole time that the line is charged. The owner of any such pipe may require the company to permit him at reasonable times and intervals to ascertain by test that the conditions specified in (ii) are complied with as regards his pipe. 9. When the return is partly or entirely uninsulated a continuous record shall be kept by the company of the difference of potential during the working of the tramway between the points of the uninsulated return farthest from and nearest to the generating station. If at any time such difference of potential exceeds the limit of seven volts, the company shall take immediate steps to reduce it below that limit. 10. Every electrical connexion with any pipe shall be so arranged as to admit of easy examination, and shall be tested by the company at least once in every three months. 11. Every line and every insulated return or part of a return except any feeder shall be constructed in sections not exceeding 0.8 km in length, and means shall be provided for insulating each such section for purposes of testing. ( L.N. 156 of 1977 ) 12. The insulation of the line and of the return when insulated, and of all feeders and other conductors, shall be so maintained that the leakage current shall not exceed 6 mA/km of tramway. The leakage current shall be ascertained daily before or after the hours of running when the line is fully charged. If at any time it should be found that the leakage current exceeds 0.3 A/km of tramway, the leak shall be localized and removed as soon as practicable and the running of the cars shall be stopped unless the leak is localized and removed within twenty-four hours: ( L.N. 156 of 1977 ) Provided that where both line and return are placed within a conduit this regulation shall not apply. 13. The insulation resistance of all continuously insulated cables used for lines, for insulated returns, for feeders, or for other purposes, and laid below the surface of the ground, shall not be permitted to fall below the equivalent of 6 MΩ/km. A test of the insulation resistance of all such cables shall be made at least once in each month. ( L.N. 156 of 1977 ) 14. Where in any case in any part of the tramway the line is erected overhead and the return is laid on or under the ground, and where any wires have been erected or laid before the construction of the tramway in the same or nearly the same direction as such part of the tramway, the company shall, if required so to do by the owners of such wires or any of them, permit such owners to insert and maintain in the company’s line one or more induction-coils or other apparatus approved by the company for the purpose of preventing disturbance by electric induction. In any case in which the company withholds its approval of any such apparatus the owners may appeal to the Chief Executive in Council, who may, if he thinks fit, dispense with such approval. ( 62 of 1999 s. 3 ) 15. Any insulated return shall be placed parallel to and at a distance not exceeding 1 m from the line when the line and return are both erected overhead, or 0.5 m when they are both laid underground. ( L.N. 156 of 1977 ) 16. In the disposition, connexions and working of feeders the company shall take all reasonable precautions to avoid injurious interference with any existing wires. 17. The company shall so construct and maintain its system as to secure good contact between the motors and the line and return respectively. 18. The company shall adopt the best means available to prevent the occurrence of undue sparking at the rubbing or rolling contacts in any place and in the construction and use of its generator and motors. 19. In working the cars the current shall be varied as required by means of a rheostat containing at least twenty sections or by some other equally efficient method of gradually varying resistance. 20. The company shall, so far as may be applicable to its system of working, keep records as specified below. These records shall, if and when required, be forwarded for the information of the Chief Executive in Council. ( 62 of 1999 s. 3 ) Daily records Number of cars running. Maximum working current. Maximum working pressure. Maximum current from the earth connexions (see rule 8(i) ). Leakage current (see rule 12 ). Fall of potential in return (see rule 9 ). Monthly records Condition of earth connexions (see rule 7 ). Insulation resistance of insulated cables (see rule 13 ). Quarterly record Conductance of joints to pipes (see rule 10 ). Occasional records Any test made under the provisions of rule 8(ii) . Localization and removal of leakage, stating time occupied. Particulars of any abnormal occurrence affecting the electric working of the tramway. 21. Any person who acts in contravention of rules 3 to 13 and 15 to 20 shall be liable to a fine at level 1, and also in the case of a continuing offence to a further fine of $10 for every day after the first during which such offence continues. ( G.N.A. 75 of 1951 ; E.R. 3 of 2021 )