| (Cap 107, sections 31 and 34) [14 May 1902] (10 of 1902 Schedule) Cap 107C rule 1 These rules may be cited as the Use of Electric Power on the Tramway Rules. Cap 107C rule 2 In the following rules, unless the context otherwise requires- "current" (电流) means an electric current exceeding one-thousandth part of one ampere; "energy" (能量) means electrical energy; "generator" (发电机) means the dynamo or dynamos or other electrical apparatus used for the generation of energy; "motor" (发动机) 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" (电线) means any wire or apparatus used for telegraphic, telephonic, electrical signalling or other similar purposes. Cap 107C rule 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. Cap 107C rule 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". Cap 107C rule 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) Cap 107C rule 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) Cap 107C rule 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 connections which shall be placed not less than 20 m apart: Provided that in place of such two earth connections the company may make one connection 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 connections herein specified cannot be constructed and maintained without undue expense, the provisions of this rule shall not apply. The earth connections 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 connection 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 connection 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 connections with the consents hereinbefore specified. (L.N. 156 of 1977) Cap 107C rule 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 connections specified in the preceding rules, as to fulfil the following conditions- (i) that the current passing from the earth connections through the indicator to the generator shall not at any time exceed either 1.2A/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 Leclanche cells connected in series if the direction of the current is from the return to the pipe, or by interposing one Leclanche 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. |
