Power Distribution Centre To Be Moved From Mangahao To Levin

Chronicle (Levin), 7 January 1949, Page 4

Power Distribution Centre To Be Moved From Mangahao To Levin

w ; Big moyes are afoot in Levin at the moment in connection with the distribution of electric power throughout the Horowhenua. Firstly, and of considerahle importance, is the materialisation of the decision to shift the distribution centre for Horowhenua from Mangahao to Levin, where a new sub-station has heen built. Second !y, is the construction of a £10,000 addition to the. Horowhenua Power Board's depot in Cambridge Street, provid-, mg storage space, garage and workshop accommodation and *a recreation and drying room for the outdoor staff.

Yesterday the full details and significance of these changes were conveyed to a "Chronicle" reporter by the Board's engineer, Mr. J. F. Bryce, who said that the substation was now completed and the equiprnent installed. The main im.mediate task was the completion of a 33,000-volt transmission line between Mangahao and Levin. It was hoped to do this before the winter, but he added that it would be at least- two years* before it woiild pe operating at the total 33,000 volts as there would be transition periods at lower voltages before the whole scheme would be in full swing. The additiohs to the main depot were now nearly completed. At the present time, said Mr Bryce, the supply for the northern portion of the board's area was drawn direct from the Mangahao power station. As the board's high tension distribution system operated at 11,000' volts, and the ihachmes at Mangahao generated at 11,000 volts, the supply voltage did not need to be stepped up or down as was the case at most points of supply. It did, however, pass through a set of i;egulating transformers which were capable of stepping the voltage up or down a few per cent. to compensate for fluctuations of voltage on the main Government system. Reasons For Change In any electric supply undertakmg, the ideal condition was to have the point of supply adjacent to the heaviest loaded portion of the area. In other .words, the supply sub-station should be at or near the centre of gravity of the load. In .the early days of the board's operations there were numerous flaxmills at Foxton and Shannon. At that time these constituted a considerable portion of the load on the board's system and Mangahao was quite a good Situation for the point of supply. ^ince those days the position had been gradually. changing and the naxmills, with the exception of the woolpack factory at Foxton, had closed down and the board's load was now predominaiitly domestic The centre of gravity of the load had changed from Shannon to Levin, . the greatest loads being poncentrated in the built-up areas. The primary distribution lines were now transmitting fairly large blocks of power to places some distance away from the main point at Mangahao, with consequent heavy line losses and voltage dron continued Mr. Bryce.. The supplying of Idw voltage not only caused the mefiicient operation of appliances and irritation to consumers, but was also" economically detrimental to the board, as the line losses were expensive and the low voltage caused loss of revenue. -These were the factors which had' brought about the decision to shift the distribution centre to Levin. The 33,000-volt transmission line now in the course of erection would be capable of transmitting a very large quantity of power with very

little loss. At the new sub-station the voltage would be stepped down to 11,000 volts and feeder lines would radiate and distribute power from this central point. The board had two points of supply, continued Mr. Bryce, one at Mangahao and the other at Paraparaumu. The Otaki Borough load was at present being supplied from the Paraparaumu sub-station, but it was anticipated ' that when the new sub-station at Levin was in operation Otaki would be fed from there, and provision was being made for a feeder line between the two tov/ns. In all six feeder lines would radiate from the new substation — two to Shannon, one to Foxton, two to Otaki, and one to the Levin borough. Equinment All Empire Made The new transmission line was being erected on Austrajian poles, while a portion of the insulators came from Canada and the balance from England. The largest item of the project — 80 tons of copper cable — came from England, while the sub-station. equiprnent was manjifactured 'by a well-known British firm. Every item of equiprnent,' therefore, had been supplied from within the Empire. The sub-station e.quipment included special protective apparatus for the high tension overhead lines, for instance, overload protection and earth leakage protection. Therefore, if a line broke and fell on the ground the protective gear opened the circuit breaker and disconnected the line from the supply. The same thing happened if a branch of a tree fouled the line, or if an insulator broke or cracked. Adding a note of warning, however, Mr. Bryce said that this did not mean that it would be safe to touch a broken wire, as the protective system worked only on high tension lines. Low tension lines often broke and remained, alive on the ground, and had caused fatalities. In any case, he added, the best appliances 'in the .world had been known to fail at times. The present set-up in regard to lmes and sub-stations had served the board -well for more than 20 years, continued Mr Bryce, and it was anticipated that rhe new arrangement, with perhaps vninor alterations from time to time, would enable an efficient service to be earried on for the next 20 years. Reviewing some of tlie features of the new portion of the board's depot, Mr. Bryce said that it was divided into four sections — a garage workshop, transformer workshop, oi! storage spabe, and linesmens accommodation. The iatter •mcluded, as weil as a drying room for we. clothes, locker space and, general recreational facilities. And about that tower which has £®erLfascinating many passers-by: Mr, Bryce says it is for renairs to the liigh transformers in the sub-. station. Special lifting gear will be installed at the top so that the cores of the transformers can be lifted out for repairs and inspection.