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 the following Associations, unanimously voted to recommend them to their respective Associations for approval or adoption:
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.
And as soon as meetings of these Associations are held, and action taken, the fact will be noted.
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.
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 3,000. Rules 32 to 37. Voltage over 3,000. Rules 38 and 39.
CLASS D.—Specifications for Wires and Fittings. Rules 40 to 55.
CLASS E.—Miscellaneous. Rules 56 to 59.
CLASS F.—Marine Wiring. Rules 60 to 72.
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 cut-outs, 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.