e>
« back to results for ""
Below is a cache of http://www.mikeholt.com/documents/nec/NCSE1899.pdf. It's a snapshot of the page taken as our search engine crawled the Web.
The web site itself may have changed. You can check the current page or check for previous versions at the Internet Archive. Yahoo! is not affiliated with the authors of this page or responsible for its content.
http://localhost:100/_HOLT_NEW/
NATIONAL ELECTRICAL CODE.



RULES AND REQUIREMENTS


of the



NATIONAL BOARD OF FIRE UNDERWRITERS


FOR THE INSTALLATION OF


WIRING AND APPARATUS


for



1 of 41
7/9/2002 11:13 AM
NATIONAL ELECTRIC CODE
http://localhost:100/_HOLT_NEW/documents/nec/1899NEC.htm ELECTRIC LIGHT, HEAT AND POWER

As Recommended by the


UNDERWRITERS NATIONAL ELECTRIC ASSOCIATION


____________________



Edition of 1899.
SUPPLEMENT

For satisfactory work only approved fittings should be used. The Supplement to the National Electrical
Code containing a list of approved electrical fittings is designed to aid wiremen by showing them in advance just
what will be approved by the Underwriters. Fittings not listed should not be used without special approval, which
will be freely given on application, if the device is found to be reliable.

The supplement will be revised quarterly.
GENERAL PLAN

GOVERNING THE ARRANGEMENT OF
RULES.

__________


CLASS A. Central Stations, Dynamo, Motor and Storage-Battery Rooms, Transformer Substations,
etc. Rules 1 to 11.

CLASS B. Outside Work, all systems and voltages. Rules 12 and 13.

2 of 41
7/9/2002 11:13 AM
NATIONAL ELECTRIC CODE
http://localhost:100/_HOLT_NEW/documents/nec/1899NEC.htm 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 300. Rules 24 to 31.
Voltage between 300 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.
GENERAL SUGGESTIONS.

In all electric work conductors, however well insulated, should always be treated as bare, to the end that
under no conditions, existing or likely to exist, can a grounding or short circuit occur, and so that all leakage from
conductor to conductor, or between conductor and ground, may be reduced to the minimum.
In all wiring special attention must be paid to the mechanical execution of the work. Careful and neat
running, connecting, soldering, taping of conductors and securing and attaching of fittings, are specially conducive
to security and efficiency, and will be strongly insisted on.
In laying out an installation, except for constant-current systems, the work should, if possible, be started
from a center of distribution, and the switches and cutouts, controlling and connected with the several branches,
be grouped together in a safe and easily accessible place, where they can be readily got at for attention or
repairs. The load should be divided as evenly as possible among the branches, and all complicated and
unnecessary wiring avoided.
The use of wire-ways for rendering concealed wiring permanently accessible is most heartily indorsed
and recommended; and this method of accessible concealed construction is advised for general use.
Architects are urged, when drawing plans and specifications, to make provision for the channeling and
pocketing of buildings for electric light or power wires, and in specifications for electric gas lighting to require a
two-wire circuit, whether the building is to be wired for electric lighting or not, so that no part of the gas fixtures
or gas piping be allowed to be used for the gas-lighting circuit.

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.
3 of 41
7/9/2002 11:13 AM
NATIONAL ELECTRIC CODE
http://localhost:100/_HOLT_NEW/documents/nec/1899NEC.htm National Association of Fire Engineers.
National Board of Fire Underwriters.
National Electric Light Association.
Underwriters National Electric Association.
Class A.

STATIONS & DYNAMO ROOMS.

Includes Central Stations, Dynamo, Motor and
Storage-Battery Rooms, Transformer
Substations, Etc.

1.

Generators
a.
Must be located in a dry place.
b.

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, can not 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.
CLASS A. STATIONS
6___________________________________________________________________

1.

Generators Continued.
e.
Must each be provided with a waterproof cover.
f.
Must each be provided with a name-plate, giving the makers name, the capacity in volts and amperes,
and the normal speed in revolutions per minute.
4 of 41
7/9/2002 11:13 AM
NATIONAL ELECTRIC CODE
http://localhost:100/_HOLT_NEW/documents/nec/1899NEC.htm
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.
c.
Must be kept so rigidly in place that they can not 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.

AND DYNAMO ROOMS.
_____________________________________________________________________________
7

3. Switchboards Continued.
c