POWER FAILURES

Hokitika Guardian, 7 February 1930, Page 8

POWER FAILURES

IMPORTANT DEVELOPMENTS IN PROGRESS.

WELLINGTON, Feb. 4

Power failures on the State hydroelectric schemes have recently occurred in three districts, and some concern has been publicly expressed regarding the reliability of the electrical supply,. The situation was discussed with the Chief Electrical Engineer, Mr. E. T. M. Kissel, by a “Times” correspondent, who found that the head of department is also concerned over the matter and has been busy investigating all its phases.

The whole of the Dominion has reoently experienced unduly severe weather conditions, and this is the chief cause of the electrical troubles, though Mr Kissell took up the attitude that safeguards must be provided to maintain the supply ever under abnormal circumstances, and that the whole scheme is being developed with this objective. A serious failure at Coleridge wav described by the Chief Engineer with the preliminary comment that coincidences piled up against the system. It wa,s extraordinary that while gales and floods had put sections of twr out of three power lines from Cole ridgte outt lof governor trouble should develop at that station. Sand used in the cores o’ machinery castings worked into the mechanism of the governor and set up a series of troubles leading to power failure. Precautions a,re take 1 ’ by manufacturers to obtain absolutely clean castings, yet some sand remained, and the further operating precautions of filtering and renewing tin oil many times during the service of nearly two years did not completely remove some -partidles, which .prevented proper operation of the delieafte mechanism. A fault developed through the failure of a pole at the Selwyn River. This threw an overload on the machines, which in the ordinary dfourse would 'have been protected by the governing mechanism, but this failed owing to the cause indicated, and the whole station had to be out out. all the machines being closed and brought hack to normal speed. The difficulty was complicated by the damaged condition of two lines through gales and floods.

GOVERNOR FAILURE AT ARAPUNI.

There was another governor failure which caused Arapuna to cut out. In this instance the reason was quite different. The generating units, owing to the long delay in completing the Arapuni contract, were stored for nearly two years, and the reednt failure disclosed the fact that a portion of the governor, which was assembled in England and not required to be opened up for erection, had corroded and cracked, causing unsatisfactory working of the governor, which had been subjected to severe conditions owing to the heavy weather which the Auckland district had been experiencing. A failure at Bunnythorpe, explained Mr Kissel, was due to fire at a sub-station caused by a 'fault in the supply cable, but this meant a stoppage of supply of only limited duration to all but the power area supplied through that station, and even in the latter case power was restored in two and a half hours. The damage was stated to be £15,000, but as a matter of fact all the material destroyed can be replaced for £SOOO.

“We are still in the initial stages of our general power distribution scheme,” added Mr Kissel, “and ns the system grows, and various power Stations become ’intercommunicated with additional transmission lines, there is no question that the reliability of supply will imensely improve Another -factor making for greater reliability is that in the early days, when materials were high priced, the v/?ry fn ini mum of switch protective apparatus was installed, but recent developments in this line make considerable improvements possible, and we are steadily installing the latest

protective apparatus available. The inter-communication of stations is being rapidly, developed. Waikaremoana and Mangahao are linked, and we are completing a survey for a transmission line connecting Arapuni with Mangah.no via Taranaki. A transmission line survey connecting'

Arapuni with Waikaremoana via Rotorua and the Urewera Country js completed. Coleridge, in the same way, will be connected with Waitaki, and if negotiations with the Dunedin corporation for the purchase of the Waipori undertaking a\re successful this supply will be linked with the Canterbury schemes.”