Fire Precautions in Electrical Stations

Abstract

SERIOUS fires from electrical plant in power stations are fortunately rare in Great Britain, but during the last few years there have been several disastrous fires both at home and abroad, and so the paper on fire precautions by F. C. Winfield read to the Institution of Electrical Engineers on February 11 is a useful one. In electrical supply it is recognized that the maintenance of this supply is the outstanding requirement. This is usually done by duplicating all the principal cables supplying the current, and also some of the plant. Since all electrical plant is subject to the two risks of fire and explosion, this provision does not secure the desired maintenance of the supply unless measures are taken to ensure that such duplicates cannot be simultaneously impaired. It is necessary therefore to provide physical separation of electrical duplicates by dividing them up in separate buildings or enclosures. Brick walls and reinforced concrete construction have excellent fire-resisting properties. Pitched roofs supported by steel trusses should be protected by a fire-resisting inner ceiling. All windows should be of wired glass and all internal doors of fireproof self-closing design. The development of the oil-less circuit and breaker on the Continent is a step in the right direction. An important factor in fighting an oil fire is the dense black smoke, which impedes or prohibits access to the seat of the fire. This is a very serious consideration in dealing with fires which occur in the inner regions of large power stations. For this reason it is recommended that all large transformers or heavy switch-gear should be mounted in separate buildings or in chambers opening to the outer air and sealed off from the inner side. Unfortunately, no practical method of routine testing has yet been devised by means of which the failures that produce fires can be anticipated.