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stant, and are used merely as a check on the regulation. It has been proposed to distinguish between this class and those which integrate, by calling the former recording and the latter registering; but common usage is the other way, and the term integrating meter is more distinctive for the latter. In most cases the simple word “meter" is understood to mean the integrating instrument, whether used for measuring gas, water, or electrical quantities.

APPENDIX I.

“NATIONAL ELECTRICAL CODE”

RULES AND REQUIREMENTS

OF THE

NATIONAL BOARD OF FIRE UNDERWRITERS

FOR THE INSTALLATION OF

WIRING AND APPARATUS
FOR ELECTRIC LIGHT, HEAT, AND POWER

· AS RECOMMENDED BY THE UNDERWRITERS' NATIONAL ELECTRIC ASSOCIATION

EDITION OF 1901 The National Electrical Code, as it is here presented, is the result of the united efforts of the various Electrical, Insurance, Architectural, and allied interests which have, through the National Conference on Standard Electrical Rules, composed of delegates from various National Associations, unanimously voted to recommend it to their respective Associations for approval or adoption.

The following is a list of the Associations represented in the Conference, all of which have approved of the Code:

AMERICAN INSTITUTE OF ARCHITECTS
AMERICAN INSTITUTE OF ELECTRICAL ENGINEERS
AMERICAN SOCIETY OF MECHANICAL ENGINEERS
AMERICAN STREET Railway AssociaTION
FACTORY MUTUAL Fire INSURANCE COMPANIES
NATIONAL ASSOCIATION OF FIRE ENGINEERS
NATIONAL BOARD OF FIRE UNDERWRITERS
NATIONAL ELECTRIC LIGHT ASSOCIATION
UNDERWRITERS' NATIONAL ELECTRIC ASSOCIATION

GENERAL PLAN GOVERNING THE ARRANGEMENT OF RULES CLASS A. - Central Stations, Dynamo, Motor, and Storage-Battery Rooms,

Transformer Substations, etc. Rules i to 11.
CLASS B. — Outside Work, all systems and voltages. Rules 12 and 13.

451

CLASS C.- Inside Work. Rules 14 to 39. Subdivided as follows:

General Rules, applying to all systems and voltages. Rules 14 to 17.
Constant-Current systems. Rules 18 to 20.
Constant-Potential systems.
All voltages. Rules 21 to 23.
Voltage not over 550. Rules 24 to 31.
Voltage between 550 and 3,500. Rules 32 to 37.

Voltage over 3,500. Rules 38 and 39.
CLASS D.-Specifications for Wires and Fittings. Rules 40 to 63.
CLASS E. – Miscellaneous. Rules 64 to 67.
CLASS F. - Marine Wiring. Rules 68 to 80.

CLASS A

STATIONS AND DYNAMO ROOMS

INCLUDES CENTRAL STATIONS, DYNAMO, MOTOR, AND STORAGE-BATTERY ROOMS,

TRANSFORMER SUBSTATIONS, ETC. 1. Generators —

a. Must be located in a dry place.

6. Must never be placed in a room where any hazardous process is carried on, nor in places where they would be exposed to inflammable gases or flyings of combustible materials.

C. Must be insulated on floors or base frames, which must be kept filled to prevent absorption of moisture, and also kept clean and dry. Where frame insulation is impracticable, the Inspection Department having jurisdiction may, in writing, permit its omission, in which case the frame must be permanently and effectively grounded.

A high-potential machine which, on account of great weight or for other reasons, cannot have its frame insulated from the ground, should be surrounded with an insulated platform. This may be made of wood, mounted on insulating supports, and so arranged that a man must always stand upon it in order to touch any part of the machine.

In case of a machine having an insulated frame, if there is trouble from static electricity due to belt friction, it should be overcome by placing near the belt a metallic comb connected with the earth, or by grounding the frame through a very high resistance of not less than 200 ohms per volt generated by the machine.

d. Every constant-potential generator must be protected from excessive current by a safety fuse, or equivalent device, of approved design in each lead wire.

These devices should be placed on the machine or as near it as possible.

Where the needs of the service make these devices impracticable, the Inspection Department having jurisdiction may, in writing, modify the requirements.

e. Must each be provided with a waterproof cover.

f. Must each be provided with a name-plate, giving the maker's name, the capacity in volts and amperes, and the normal speed in revolutions per minute.

2. Conductors

From generators to switchboards, rheostats, or other instruments, and thence to outside lines.

a. Must be in plain sight or readily accessible.

b. Must have an approved insulating covering as called for by rules in Class “C” for similar work, except that in central stations, on exposed circuits, the wire which is used must have a heavy braided non-combustible outer covering.

Bus bars may be made of bare metal,
6. Must be kept so rigidly in place that they cannot come in contact.

d. Must in all other respects be installed under the same precautions as required by rules in Class “C” for wires carrying a current of the same volume and potential.

3. Switchboards –

a. Must be so placed as to reduce to a minimum the danger of communicating fire to adjacent combustible material.

Special attention is called to the fact that switchboards should not be built down to the floor, nor up to the ceiling, but a space of at least ten or twelve inches should be left between the floor and the board, and from eighteen to twenty-four inches between the ceiling and the board in order to prevent fire from communicating from the switchboard to the floor or ceiling, and also to prevent the forming of a partially concealed space very liable to be used for storage of rubbish and oily waste.

b. Must be made of non-combustible material or of hardwood in skeleton form filled to prevent absorption of moisture.

6. Must be accessible from all sides when the connections are on the back, but may be placed against a brick or stone wall when the wiring is entirely on the face.

d. Must be kept free from moisture.

e. Bus bars must be equipped in accordance with rules for placing conductors.

4. Resistance Boxes and Equalizers —

(For construction rules, see No. 60.) a. Must be placed on a switchboard or, if not thereon, at a distance of a a foot from combustible material, or separated therefrom by a non-inflammable, non-absorptive, insulating material.

5. Lightning Arresters

(For construction rules, see No. 63.) a. Must be attached to each side of every overhead circuit connected with the station.

It is recommended to all electric light and power companies that arresters be connected at intervals over systems in such numbers and so located as to prevent ordinary discharges entering (over the wires) buildings connected to the lines.

.

b. Must be located in readily accessible places away from combustible materials, and as near as practicable to the point where the wires enter the building.

Station arresters should generally be placed in plain sight on the switchboard.

In all cases, kinks, coils, and sharp bends in the wires between the arresters and the outdoor lines must be avoided as far as possible.

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1. Testing of Insulation Resistance

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b. Where coats ocsly indicatiag detectors are 300 feasibie, the circuits shocd be tested at least once per day, and preferabey oftener.

c. Data obtained from a tests Iust be preserved for examination by the Inspection Department havisz jurisdiction.

These roles on testing to be applied z such places as may be designated by die Inspection Depart

8. Motors

a. Must be insulated on floors or base frames, which must be kept filled to prevent absorption of moisture; and must be kept clean and dry. Where frame insulation is impracticable the Inspection Department having jurisdiction may, in writing, permit its omission, in which case the frame must be permanently and effectively grounded.

A high-potential machine which, on account of great weight or for other reasons, cannot bave its frame insulated, should be surrounded with an insalated platform. This may be made of wood mainted on insulating gapports, and so arranged that a man must stand upon it in order to touch any part of the machine

In case of a machine having an insulated frame, if there is trouble from static electricity due to belt friction, it should be overcome by placing near the beit a meta-sc comb connected to the earth, or by grounding the frame through a very high resistance of not less than 200 chas per volt generated by the machine

b. Must be wired under the same precautions as required by rules in class “C”, for wires carrying a current of the same volume and potential.

The leads or branch circuits should be designed to carry a current at least fifty per cent greater than that required by the rated capacity of the motor to provide for the inevitable overloading of the motor at times without overfosing the wires.

c. The motor and resistance box must be protected by a cutout and controlled by a switch (see No. 17 a), said switch plainly indicating whether “on” or “ off" Where one-fourth horse-power or less is used on low-tension circuits

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