CO882-(8-9) — Page 397

PUBLIC RECORD OFFICE

Reference :---

C.O. 882

9

PUBLIC RECORD OFFICE, LONDON

ALLY WITHOUT PERMISSION OF THE BE REPRODUCED PHOTOGRAPHIC- | COPYRIGHT PHOTOGRAPH-NOT TO

6

insulation of all parts

6. A high pressure eircuit shall not be brought into Testing of use unless the insulation of every part thereof has with- stood the continuous application, during half-an-hour, in of high the case of every electric line of a pressure twice the pressu (→ maximum pressure to which it is intended to be subjected circnis in use, and, in the case of every machine, device, or apparatus, of a pressure 50 per cent. greater than the said maximum pressure.

The company shall duly record the results of each test.

insulation.

7. The insulation of every complete circuit used for the Mainten supply of energy, including all machinery, apparatus, and ance of devices for ning part of, or in connection with, that circuit, shall be so maintained that the leakage current shall not under any conditions exceed one-thousandth part of the maximum supply current; and suitable means shall be provided for the indication and localisation of leakage. Every leakage shall be remedied without delay.

Every such circuit shall be tested for insulation at least once in every week, and the company shall duly record the results of the testings.

Provided that where any part of any electric circuit is connected with earth, either in accordance with these regulations or with the approval of the Director of Public Works, the provisions of this regulation shall not apply to that part of that circuit so long as the connection with earth exists.

breaker

8. Every high pressure main, conductor, or other Circuit- suitable fuse or auto- for high apparatus shall be protected by matic circuit-breaker.

pressure

mains, &c.

Provided that it shall not be incumbent upon the company to provide such a fuse or circuit-breaker for the outer conductor of a concentric main which is, in accord- ance with these regulations or with the approval of the Director of Public Works, efficiently connected with earth.

9. In every case where a high pressure supply is Trans- transformed for the purpose of supply to one or more consumers, some suitable automatic and quick-acting means shall be provided to protect the consumer's wires from any accidental contact with or leakage from the high pressure circuit, either within or without the transforming apparatus.

formers.

Connec- 10. The metallic portion of every high pressure trans- tion of former, with the exception of the conductors thereof, shall trans- be efficiently connected with earth.

formers

with earth.

11. Where any portion of any electric line or any Protection support for an electric line is exposed in such a position from

as to be liable to cause injury froin lightning, it shall be lightning. efficiently protected against such liability.

to Director of Public

12. Where any accident by explosion or fire, or any Report of other accident of such kind as to have caused or to be accidents likely to have caused loss of life or personal injury has occurred at any part of any electric line or work, the Works. Company shall give immediate notice thereof to the Director of Public Works.

Overhead Lines.

Overhead lines in

18. (1) The provisions of this regulation shall have case of low effect in the case of overhead lines for low pressure and pressure medium pressure continuous current supply and for low and pressure alternating current supply.

medium

pressure

supply.

(2) The interval between any two wooden poles used singly as supports for an overhead line shall not excee 200 feet; provided that where the line makes an angle at any such pole, the interval between that and the next pole shall not exceed 150 feet. In the case of supports other than single wooden poles the intervals between the supports shall be such as may be prescribed by the Director of Public Works.

(3) Every support for an overhead line shall be of a durable material, and shall be properly stayed against forces due to wind pressure, change of direction of the line, or unequal lengths of span. The factor of safety shall be for overhead lines at least 5, and for wooden poles at least 10, and for iron or steel structures at least 6, taking the maximum possible wind pressure at 30 pounds per square foot.

(4) All overhead lines shall be attached to insulators, and shall be so guarded that they cannot fall away from the support.

(5) An overhead line, placed after the date of these regulations, shall not in any part thereof be at a less height from the ground than [Qu. 22] feet, except with the con- sent of the Director of Public Works, and shall not be accessible to any person without the use of a ladder or other special appliance.

(6) Where a supply is given by overhead lines on the three-wire system, the positive and negative conductors shall be placed side by side above the intermediate conductor. The intermediate conductor shall consist of two wires placed side by side at a distance apart greater than that between the positive and negative conductors, and connected in each span by two cross wires placed in such a manner that in the event of either the positive or negative conductor breaking it shall fall on one at least of the cross wires.

(7) Where a supply is given by overhead lines from a two-wire system, with the negative conductor connected with earth, the positive conductor shall be placed above the negative conductor in such a manner that in the event of breakage it must fall on the negative conductor.

(8) Service lines from overhead lines shall be led as directly as possible to insulators firmly attached to some portion of the consumer's premises which is not accessible to any person without the use of a ladder or other special appliance. Every portion of any service line which is outside a building, and is within 7 feet from the building, shall be efficiently protected by insulating material,

(9) Where an overhead line crosses a street, the angle between the line and the direction of the street at the place of crossing shall not be less than 60 degrees, and the spans shall be as short as possible.

(10) Where an overhead line crosses, or is in proximity to, any other wire or metal, precautions shall be taken by the company against the possibility of the line coming into contact with the other wire or metal or of the other wire or metal coming into contact with the line by break. age or otherwise.

(11) Every overhead line, including its supports and all the structural parts and electrical appliances and devices belonging to or connected with the line, shall be daly and efficiently supervised and maintained as regards both electrical and mechanical conditions.

(12) The company shall remove any overhead line upon cessing to use it for the supply of energy, unless

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