Fire Hazards of Radio Sets
Summer brings with it the hazard of lightning in connection with radio receiving sets. The possibility of the radio antennae being struck usually receives some consideration, but it is a known fact, according to the National Fire Waste Council of the Chamber of Commerce of the United States, that many receiving sets are not safeguarded against destruction in this manner. One never knows where lightning will strike, but if properly protected, radio antennae should not cause anxiety from this source.
An aerial may be safeguarded by a protective device known as a lightning arrester which is installed in the lead-in wire as near as practicable to the point where the wire enters the building. This protector should not be placed in the immediate vicinity of easily ignitible material or where exposed to flammable gases or combustible dust and flyings.
The most important precaution a radio operator should take is to keep the antennae clear of all electric light and power wires. A number of cases have been known where aerials have fallen across or come into contact with trolleys or high voltage cables resulting in loss of life. The National Electric Code requires that antennae and counterpoise outside buildings shall be kept well away from all electric light and power wires of any circuit of more than six hundred volts, and from railway trolley or feeder wires, so as to avoid possibility of contact under accidental conditions. Antennae should be installed in such manner that there will be no swaying during stormy or windy periods.
Aerial wires are often supported from chimneys or masts which are tied to chimneys. The application of this additional stress and leverage has resulted in many cases in the cracking of the brick work. This is a serious condition because of the fire hazard involved in cracked chimneys. Where such conditions exist they should be remedied at once. If an iron mast is used to support the antennae it should be grounded as a precautionary measure against lightning. An effective ground may be obtained by running a copper wire in as straight a line as possible to water piping or metal buried several feet underground.
The current from a six volt storage battery is sufficient to cause fire if the terminals or the wires leading from them become crossed. Care should be taken to avoid this. All wiring should be installed in an improved manner. Lead-in wires and other inside wiring should not be permitted to come in contact with light and power wires.
The following brief suggestions may be of value to local fire prevention committees:
- Keep all radio antennae and wiring away from electric light and power wires.
- Do not attach antennae to old brick chimneys.
- Ground metal masts used to support antennae.
- Take sufficient precautions to prevent crossing of storage battery terminals or wires.
- Provide approved protective devices in lead-in wires.