ELECTRIC SHOCK

Nelson Evening Mail, Volume LXIV, 19 January 1931, Page 8

ELECTRIC SHOCK

SOME RISKS EXPLAINED

BATHROOM HEATERS

A letter which appeared in “The Post’’ some little time ago over the pen name- of “Engineer” dealing with dangers of shock from electrical apparatus has prompted some inquiries, the results of which appear in the “Evening Post.” Mr' G. Lauchlan, assistant general manager of llie Wellington Electricity Department, suggested to a reporter that many points were of general interest.

“Engineer” had made a statement in his letter, said Mr Lauchlan, as to tlie danger which threatened people who hosed down their house fronts and turned the stream of water on the main leads into the house. One inquirer had asked whether the same danger would not lie met with if a person leaned against or placed a hand on a, house wall below the leads after a shower of rain.

Probably, said Mr Lauchlan, “Engineer’s” letter had been taken so seriously by some people that never again would they risk hosing down any part of a, house within cooee of the power leads, but, as a matter of fact, there was nothing in the suggestion that a fatal or any other shock could he received in that way. The same question had been raised by lire brigades at one time or another, but the brigades were concerned with possible dangers from high tension lines, carrying from 3000 to 4000 volte. In that case, too, the risk was practically nil, as had been demonstrated on several occasions, here and overseas.

RISK EXCEEDINGLY SMALL Tests were made by Mr H. J. Hardie, electrical engineer in charge of the Rotorua district, which proved that the risk of persons receiving shocks along a stream of water from a hose is exceedingly small. It was shown that even when a hose was played from a distance of 20 feet on a bare wire carrying power at 400 volts there was.-mo discomfort whatever to the person holding the hose, and that the instruments used showed no measurable deflection. In the low voltage (housebold current) test the hose was played on the bare wire from one inch, and nothing happened except that the wire got very wet.

,Mr Hardie’s conclusions were that water could be directed on to leads carrying 3300 volts at a distance of 15 feet without any danger, and, that being so, the statement that householders ran a risk hosing their houses was nonsense.

The main leads in the house were a possible source of danger when houses were being repainted, said Mr Lauchlan, for it was always possible that the painter might slip and grab the wires, or have one hand on a wire and the other on the roofing of a downpipe. At the request of the Painters’ Union provision had been made that upon request the supply authority must cut the power off to allow painting operations to be carried out, and that provision should be availed of to make, sure. SOME REAL DANGERS If there was no danger from hosing, continued Mr Lauchlan, there were real dangers in some of the things which people did with electrical apparatus. 'Die tragic death of a Wellington lady in a bathroom through touching a radiator placed near the bath was proof of one of the greatest risks, far to frequently taken. Consumers who carried radiators into bathrooms were creating for themselves the precise conditions which created danger of shock. Floor, walls, and atmosphere were damp and steamy, and any person standing on a damp floor and handling a radiator ran a serious risk. In that case the radiator was handled from the bath itself; there happened to be an unsupectecl weakness in the insulation of the wires to the heating element of the radiator, so that the frame was alive, and immediately it was toueed the full 230 volts flowed through the victim’s body. “There is only one safe rule for radiators in bathrooms,” said lan. “Never carry them there.”

PORTABLE LAMPS ABOUT CARS

Another risk frequently taken by people who should know better was in working about motor-cars with a. long flex and a portable lamp. According to the regulations, a special type of insulated and guarded portable lamp should be used ill such work, but any number of car owners, and some 'garage proprietors, went cheerfully to work with unprotected extensions and light holders, hung them on the car while they climbed underneath, or laid them down on wet concrete and crawled by them and over them—and every so often there was a tragedy. Not infrequently the Department’s officers found that garage workers had removed the guards from portable lamps, preferring them bare, possibly for the sporting risk. “As long as everyone is all right no harm comes, but the slightest baling of the leads or a faulty contact with the lamp holder and everything is set for trouble.’ I n ordinary circumstances, said Mr Lauchlan, slight weakness in insulation need not make for trouble. it would be possible, for instance, for the whole household to handle a radiator or a light extension which was defective in insulation and the frame of which was therefore more or less alive, without anv suggestion of tingle, let alone shock, in a dry living or bedroom, but in a steamy bathroom or about a car or wet concrete lloor the radiator or flex would become at once a danger.

CHEAP APPLIANCES NOT ALWAYS SAFE

Unfortunately the control over the sale of apparatus was not as complete as it might be, he continued, and so iiiivone could walk into a shop and puichase equipment which passed muster, and not much more, apparatus which was put together to sell and from winch nothing like the safe usable life of standard appliances could be hail. Weakness in insulation, etc., were much more likely in such appliances than in standard goods. ’the supply engineers, Air Lauchlan mentioned, had repeatedly urged the Government to set up an approval board to approve or remove from tho market all apparatus offered the public. Portable apparatus, concluded -')> Lauchlan, should never be placed in any position where it might come m contact with earthed metal or conducting material, unless that apparatus was specially designed and protected to remove danger of shock. Earthed metal consisted ot water pipes, baths, sinks, piping of any kind connected with water, gas or other services. and conducting material included damp concrete floors, brick walls, and so on. The metal of cars, as emphasised earlier, might also lead to trouble.