The Birmingham age-herald., 1922-05-14
NEW RULES ISSUED BY UNDERWRITERS
 FOR RADIO WIRING
Every One Should Belnformed on Fire Protection Re- quirements of lnSur-
 ance Men

dnCe Wen
 All radio fans want to be careful to guard against fire and lightning At the request of The Age-Herald' A. M. Schoen, chief engineer of the Southeastern Underwriters associa- tion, has supplied the latest rulings of the underwriters on installing radio apparatus. Everyone who has a sending or receiving station should inform himself fully to guard against accidents. These are the rules pre- pared by the National Fire Protec- tion association:
 Corrected Final Report-The fol- lowing requirements are submitted as proposed revisions of rule Ss, Ma tiona Electrical Code:
 SC. Radio Equipment Note: These rules do not apply to radio equip ment installed on shipboard. In set ting up radio equipment all wiring pertaining thereto must conform to ths general requirements of this code for tho class of work installed and the following, additional speci- fications:
 For Receiving stations Only
 Antenna
 (a} Antennas outside of buildings shall not cross over or under cleo trio light or power wires of any cir cult of more than six hundred (6oO) volts. or railway trolley or feeder wires, nor shall 1t be so located that (,JI af of f6A above mentioned electric light or power wires can result in . contact between tho antenna and such cleo tric light or power wires.
 Antennas shall be conntructed and installed in 6 strong and durable manner and shall be so located as 10 prevent accidental contact with light and power wires by tagging or swinging.
 Spices and joints in the antenna span, unless made with approved clamps or splicing devices, shall be soldered-
 Antennas installed inside of build 'ings are not covered by tho above specifications.
 LeaA-fn Wires
 Cb) Iead-in wires shall be of cop per-c1ad steel or other approved metal which will not eorrode excessively, and in no case shall they be smaller than No. 1I B. 6 2. gage, except that approved ccpper-clad steel not less than No. IT. B. & s .gage, may be used.
 Lead-in wires on the outside of buildings shall not come nearer than four (4) inches to electric light and power wires, unless separated there from by . continuous and firmly h1@ xuff in tain permanent separation The non conductor shall be in addition to any insulation on the wire.
 Leadin wires shall enter building through non-combustible, non absorptive insulating pushing.
 Protective Device.
 Gel Each lead-in wire shall bs pro- vided with an approved protective device properly connected and located (nside or outside tho building), as near as practicable 10 the point where the wire enters the building. Tho protector shall not be placed in the immediate vicinity of easily4 fgnitable stuff. nor where exposed to inflammable gases or dust or f1yfngs of combustible materiAls.
 The protective device shall be an approved lightning arrester which will operate at . potential of five hundred f5oo) volts or less.
 The use of an antenna grounding switch is desirable, but does not ob- viate the necessity for the approved protective device required In this section. The anterna grounding switch. if installed. shall. in It's closed position, form q shunt around the protective device.
 Protective Ground Wire
 q ~rxt~ A~~ or insulated and shall be of copper or approved copper-clad steel. If of copper. the ground wire shall be not smaller than No. t4, B. & s. gage, and If of approved copper-clad steel it shall be not smaller than No. IT, E. & s. gate. The ground wire shall he run in es straight . line as possible to good permanent ground. Preference shall be given to water piping. Gas piping shall not be used for grounding protective de- vices. Other permissible grounds are grounded steel frames of buildings or other grounded metallic work in the building. and artificial grounds such as driven pipes, plates, cones, etc. ~
 The ground wire shall be protected against mechanical injury. An ap- proved ground clamp shall be used wherever the ground wire IS con- nected to pipes or piping.
 Wires Inside Buildings.
 Gel Wires inside buildings shall~be securely fastened in workmanlike manner and shall not come nearer than two CD inches to any electric light or power wire unless separated therefrom by. some continuous and firmly-fixed non-conductor making a permanent separation. This non- conductor shall be in addition to any regular insulation on the wire. Porce- lain tubing or approved flexible tub ing may be used for encasing wires to comply with this rule.
 Receiving Equipment Ground Wire
 CD The ground conductor may be bare or insulated and shall be of copper approved copper-clad steel or other approved metal which will not corrode excessively under existing conditions. and in no case shall the ground wire be less than No. 14, B. < s. gage, except that approved
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