ELECTRICITY SUPPLY.

New Zealand Herald, Volume LXIV, Issue 19718, 18 August 1927, Page 12

ELECTRICITY SUPPLY.

GREAT DOMESTIC LOAD. SOME LINES OVERTAXED. CASES OF LOW VOLTAGES. THE SUBDIVISION OF AREAS. • I ■The penalty for progress in Auckland's electricity supply business is that demand t sometimes exceeds the means of receiving , current at full efficiency voltage. The con- , sequence is that in areas so affected lights ■ become dull, the eye-strain from reading, and sewing increases and the ordinary; member of the community wonders what is happening at the power-house. ; Here- it should be said that the Power Board authorities are not prepared to ac- i cept responsibility for poor power reception in every case. Sometimes they find the installation .is at fault, for which the contractors or the material they use aie to blame. They admit, however, that their ; present difficulty is to keep pace with the demand in tho reticulation system, the, capacity of which in each area has constantly to be increased in one way or an- - other. The difficulty' is not simply one relating to complete subdivisions. It is made much more complex by differing degrees of voltage within them. The mains of one stfeet may become overloaded, although the general efficiency of supply in the area may . be satisfactory. Thus, to use an expert's ■unscientific term, a good deal of "juggling" has to be done to build up or give i relief. Standard for Efficiency. The standard working pressure of electricity supply for domestic purposes is ■ 230 volts, but a margin of 5 per cent. ; either way ii allowed. Thus, a pressure of j 218.5 volts is legally permissible. The Power Board, however, does not regard i such a pressure as adequate for efficient j service, and tries to limit the margin to j 2j per cent, either way. At the present time, however, a deficiency of more than 5 per cent, is taking place, in some localities. Readings taken; in Remuera Road, beyond Victoria Avenue corner, have shown on several evenings a minimum of 195 volts, a pressure entirely inadequate for efficient lighting. The house in question has no electrical installation for cooking or the heating of water, and the fault therefore cannot lie with the capacity of the leads into it being taxed beyond their original purpose. In Halston Road, beyond the Dominion Road terminus, a Voltage of 220 was recorded at 6.30 p.m., and in Mont Le Grand Boad, in the same district, but in another supply area, the reading was 210 volts at the same hour. This dropped to 200 as soon as the cooking switches were turned on. In Mount Eden Road at 7 p.m. the pressure recorded was 220 volts, and be tween seven and eight o'clock 235 was registered in Green Lane. 235 in Manukau Road, near King George Avenue corner, 225 in Remuera Road, west of Victoria Avenue, and 235 in Newmarket. Between five and six o'clock 225 was obtained in Herne Bay, and 235 in the D.C. city area. Difficulty ol the Board. Discussing the matter, Mr. R. H. Bartley, general manager of the Auckland Electric Power Board, said there was not the slightest doubt that at the rate at which the board's business was increasing, particularly in domestic supply, there must be periods when the regulation of lines got behind-hand. New consumers were being added at the rate of 100 a week, and many people already using electricity for lighting were adding to the load By installing stoves and water heaters. A general idea of the situation could be formed from the fact that although the estimated consumption by 1930 was 15,000 h.p., a supply of 26,000 h.p. had been touched last winter.

When the city had been divided into areas' originally, sections of half a mile radius had been taken. For these areas transformers then had adequate capacity, but as supply was being built up areas -with a radius of a quarter of a mile were being created arid 10 or 11 gangs were constantly engaged in this work of subdividing and reinforcing mains. More Copper and Transformers.

The whole thing was simply one of sufficient copper and sufficient transformer capacity. When the reticulation system was begun, it was known that #t soroe indefinite time the load would be such that more copper and more transformers would be necessary, but it would have been highly uneconomic to have bung up money in the air against the needs of this future day. When voltage fell through, more and more consumers tapping a line, the mains ■were increased and new transformers erected. Naturally, the board watched supply pressure very carefully and had three volt-meters constantly at work in order to check it, because it was not business to supply at an inefficient pressure. At the same time the co-operation of the consumers was required, and he welcomed information. If any consumer ,was not satisfied with light or power, he should at once inform the board, which would test the pressure and correct any deficiency at the . earliest moment. It' might, and did Sometimes, happen that a street some distance from the transformer or on a blind end might experience a deficiency although the area in general was satisfactorily served. In such cases relief could be provided perhaps by linking the ends of two streets similarly situated or by increasing the mains. Sometimes the matter .could be remedied by cutting out an area from = one transformer that was being overtaxed and adding it to one, which had power to spare. Subdivision of Kemuera Area. In regard to the low voltage reported from Rerauera Road, the situation was already in hand, a gang being engaged in Upland Road and Rangiioto Avenue upon subdividing the area, putting in another transformer and installing another feed cable. When this work was" finished ■the present transformer would have about half its present work to do and would be equal to the demands upon it. 'While appreciating the difficulties of the board in coping with (he demands of,a rapidly-growing business, it is in he. remarked that the drop in voltage m the Mont Le Grand h ouse v/hf-ri the cooking switches were turned <>t> ind-'-at.es : hat .the leads into the house are n.-adr-mia'p. •' In this case a water-heater and an el<>c-tric-stove were installed after the light, ing installation, but it is the. duty of the board to see that leads are equal to the demands of the house.