Fires of electrical origin in factories

Maintenance of electrical equipment in a manner appropriate to its importance is urged as a means of combating an increasing proportion of industrial fires of electrical origin NO ONE will question the statement that electricity in its various uses is a potential source of fire hazard. It usually is kept well under control, but too frequently it “kicks over the traces” and so-called breakdowns occur, many times attended by excessive local heating which ignites insulation, and fire spreads to near-by combustible materials. After a fire starts, conditions determine its extent. Usually it is quickly put out, but sometimes it causes serious loss. It has been said that the lack of a horseshoe nail caused Napoleon to lose the Battle of Waterloo. A case is known where the breaking of some small washers needed to limit the travel of the movable contacts of an oil switch finally resulted in a fire which so damaged an exceptionally large manufacturing plant that 80 per cent of its power requirement was interrupted for about 1 1/2 days. Electricity is by far the principal cause of fire in the properties insured by the Associated Factory Mutual Fire Insurance Companies. For the year 1940, of all fires reported to them for which claim was made, 21.9 per cent were of electrical origin, and this figure does not include the losses to electrical equipment when lightning was the initial cause. About 5 per cent can be added if lightning losses are included. The amount of all electrical losses in 1940 was 13.9 per cent of the total loss occasioned by fires of all causes. No exceptionally large single electrical loss occurred last year, so the percentage happens to be fairly low. In 1939 it was 65 per cent of the total.