Combustible Material in Electric Power Stations

Abstract

EABLY in this century, after a fire at Bristol, rubber-covered cables for switchboard work were rarely used. The recent inquiry on the fire at the Kingston Power Station should accelerate the demand for the use of non-combustible materials alone in main power stations. It was stated in evidence that about 850 gallons of inflammable oil and about 14,000 Ib. of solid compound fed the flames. Fires due to oil have been perhaps more numerous in America and Germany than in Great Britain; but recent events show the necessity of getting control of a fire in a power station at the earliest possible moment. The modern oil circuit-breaker (switch) has proved very trustworthy in practice. At its rated capacity it will clear any electric faults with certainty; but in very exceptional circumstances it may fail. The chiefs of supply stations are now paying great attention to the problem of oil-less circuit breakers. Several foreign makers have for the last few years been successfully producing oil-less breakers, particularly the A.E.G. Co. in Berlin, the Brown-Boveri Co. and the Oerlikon Co. in Switzerland. The A.E.G. Co. manufactures a special breaker called a chemical resin breaker for service in unattended substations where the air-blast type could not receive adequate supervision and maintenance. A very profitable and urgent line of inquiry for the industrial research worker would be to try to discover non-combustible liquids and solids of high insulating value for transformers, switches and electric wires. Some fairly satisfactory liquids and compounds have been found, but their cost at present is far too high for use in bulk. It is all a matter of finance. Textile glass has recently been invented. It seems probable that as a wrapping for electric wires it will have a great future.