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DYNAMOS AND MOTORS. 63. They must be located in dry places, not exposed to Ayings of combustible material, and must be insulated upon dry wood, filled to prevent absorption of moisture. They must be kept thoroughly clean and dry. They must be self-regulating, or a competent person must be in attendance near the machine whenever it is in operation. In wiring for motive-power, the same precautions should be taken as with a current of the same volume and potential for lighting. The motor (and resistance box) should be protected by a cut-out, and controlled by a switch.


64. Converters must not be placed inside of any building. They may be placed on the outer walls when in plain sight and easy of access, but must be thoroughly insulated from them. If placed on wooden walls, or the woodwork of stone or brick buildings, the insulation must be fireproof. When an underground service is used, the converter may be put in any convenient place that is dry and does not open into the interior of the building; this location must have the approval of the inspector before the current is turned on.

65. The converter should be enclosed in a metallic or non-combustible case.

66. If for any reason it becomes necessary that the primary wires leading to and from the converter should enter a building, they must be kept apart a distance of not less than twelve inches, and the same distance from all other conducting bodies. The insulation of the wire must be of the very best.

67. Safety fuses must be placed at the junction of all feeders and mains, and at the junction of mains and branches where necessary, also in both the primary and secondary wires of the converter, in such a manner as not to be affected by the heating of the coils. Secondary wires, after leaving the converter, will be subject to rules already given for services, inside wiring, etc.

68. Any provision for grounding the secondary circuit

by means of “film cut-out” or other approved automatic device, will be approved. A permanent ground will not be approved.


69. Companies or individuals furnishing electricity from central stations must enter into an agreement with this Exchange, binding themselves to maintain at all times in their stations some approved device to indicate any escape to earth, which may tend to develop leakage to water or gas pipes, or other earth connections within buildings. This approved means of testing shall also apply to separate or isolated plants, where special conditions of moisture exist, or in buildings snbject to mechanical changes of piping, etc.

70. The signing of these Rules and Requirements shall constitute and be considered an agreement on the part of the signer, that such approved device or tell-tale shall at all times be employed on their circuits.

71. The wiring in any building must test free from “grounds” before the current is turned on. This test may be made with a magneto that will ring through a resistance of 10,000 ohms, where currents of less than 200 volts potential are used.

72. All incandescent work should be inspected before being concealed, and notice should be given this Exchange as soon as work is commenced.

73. The New England Insurance Exchange reserves the right at any time to add to, change, or modify these Rules, and to enforce such modifications, changes, etc., as it shall deem necessary for safety; and it will use all reasonable efforts to promptly notify all Electric Light Companies of any change.

74. Any additional loading of wires, either in a building as a whole, or in any department thereof, without the previous approval of the Exchange, or the Inspector, shall be deemed a sufficient cause for the suspension of permits until such approval is secured. (See Form F, Inspector's Certificate.)

NOTES. A certificate for all new work or changes in old work (Form C. for Arc, Form F. for incandescent) should be signed by the party installing or controlling any apparatus. The certificate should be filed with the Secretary of the Local Board of Fire Underwriters having jurisdiction, if there be such, otherwise with the Secretary of the New England Insurance Exchange, Boston.

This certificate is relied upon as a guarantee until the work can be inspected. Permits for the use of the light or power, may be granted as soon as the certificate is duly filed.

Concealed work should be inspected before being covered up, and as a rule, incandescent work generally should be inspected before current is turned on.

The above Rules and Requirements are jointly adopted by the New England Insurance Exchange, “Associated Factory Mutuals,” and Boston Fire Underwriters' Union, and are applicable to all Electric Lighting and Power work in New England, exclusive of buildings in the State of New Hampshire not insured by the “ Associated Factory Mutuals."

[Also adopted by the New York State Board.]


WRITERS. Amended Standard for Electric Equipments, Adopted

February 27, 1889.


CAPACITY OF WIRES. 1. The conducting wires must be of copper and must have a weight per running foot at least equal to that of the wire (or parallel group of wires) constituting the main circuit of the magnetic regulator of the electric lamps (arc lamps), or of the armature of the machine employed, whichever of these is greatest.

JOINTS OR SPLICES. 2. All joints on wires must be so made as to secure perfect and durable contacts, which shall always maintain a degree of conductivity at the joint, at least equal to that of the wire generally.

3. The joint must be so made as in the ordinary “telegraph splice” that it is mechanically secure against motion or displacement and must then be further electrically connected by solder so applied as to leave no corrosive or otherwise injurious substance on the connection. After joining and soldering, the joint must be covered with insulating material in such a way as to make the insulation of the joint as good as that of the rest of the line.

4. A joint made by the process of electric welding would be the equivalent of one made as indicated above, but no joint depending on solder for its mechanical integrity either wholly or in part will be allowed.


5. Outside wires must be covered with at least two coatings, one of insulating material impervious to water, next to the wire, and the other of some substance fitted to resist abrasion or like mechanical injury, and must be firmly secured to substantial approved 'insulators, adequately supported. All “ tye wires” or those used to secure the conductors to the “insulators " must be themselves covered with waterproof insulating and mechanically resistant material similar to that used on the conductors themselves.

6. Overhead conducting wires must be supported on poles as far as possible, so that they can be easily reached for inspection, and when this cannot be done, and special permit is granted allowing them to be carried over attached to buildings, they must be supported at least seven feet above the general level of the roof and at least one foot above the ridge of “pitch roofs.”

7. Where wires approach buildings to enter them they should be so located as not to be readily reached by the occupants of such buildings, and in the case of arc light systems must maintain a minimum distance of ten inches and for incandescent systems of six inches except where the wires are carried in conduits.

8. When these exterior electric light wires are near other conductors of any kind capable of carrying off a part of the current if contact should be made, dead insulated guard-irons must be placed so as to prevent such contact in case of accident affecting the wires or their supports.

9. Like precautions must be taken where acute angles occur in the line wires.

10. Overhead wires from the main circuit or pole lines in the street to the insulators attached to the buildings which they enter, must not be less than ten inches apart for arc wires or six inches for incandescent wires carrying currents of 250 volts E. M. F. as a maximum. They must be securely and rigidly supported on "insulators ” of glass, porcelain or other approved material.

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