Electric Power

Waipukurau Press, Volume XXII, Issue 288, 19 November 1928, Page 7

Electric Power

IN CENTRAL HAWKE’S BAY

The following report for the month was submitted by the engineer (Mr J. K. Lee) at the meeting of the Central Hawke’s Bay Electric Power Board on Friday: —

"Since I last reported, nothing of very great moment has occurred. On November Ist, fault developed on Cook Street, sub-station, Waipukurau, due to a cracked insulator on the isolating switch, and the trouble extended back to a switch on the main sub-station at the power-house, Waipukurau, causing a very extensive flare-up at both places, but the damage done was small. Current was off in Waipukurau for approximately 45 minutes, and in the rest of the area for two or three minutes, while repairs were being effected. "On October 23, November 2, and again on November 10 the circuitbreaker at Onga Onga opened, and could not be closed until some reduction was made in the load. This difficulty is not now possible, as the new cable has been put into the circuit, with the result that the load is carried by two circuit-breakers. "Referring to the discussion that took place at the last meeting of the Board about transmission losses, which I stated were 22 per cent of the current taken from the Public Works Department, the main portion of these losses occur in transformers, due mainly to the current necessary to energise the apparatus, and the losses are greater in proportion in small transformers. On the Mangahao system the losses amount to 17 per cent of the total output of the station, and there are only approximately 10 sub-stations of very large capacity being supplied. Therefore, this Board’s losses must necessarily be much larger, seeing that we have approximately 125 sub-stations of very small capacity, and in the large number of cases the supply is stepped down to a lower voltage, which increases the losses very appreciably. "Another source of loss is the C2R losses in the reticulation, and this is governed by the size of the cables used. On account of capital outlay, the cables in this Board’s area were kept down to a minimum by your consulting engineers, and the losses are much greater than would have been the case if the present development had been foreseen and the network built such as the present load warranted.

“I have made some approximate calculations regarding the current consumed in energising the transformers at present in the area, and I have evolved the fact that we are consuming approximately 71 units per hour for every hour that supply is given; every unit sold last year cost the Board 1.61 pence, so that the cost to the Board is nearly £ll 10/- per day. “A further source of losses has been investigataed by me. The Board has installed approximately 1700 metres, and in each meter there occurs a loss of 1.5 watts in the potential coil; this means that every hour 25.5 units are used. Calculated in terms of money, this means a further loss of £4 8/6 per day. “The matter of comparison between the operations of the Dannevirke Board as compared with this Board, as asked for by the chairman, is not yet complete, and will be presented at the next meeting. “Installations for the month were:

New consumers, 5; 'hot water services, 3; shearing motor, 1; other motors, 2; ranges, 2; additions to existing installations, 30.”