NEW PLYMOUTH POWER

Taranaki Daily News, 23 September 1940, Page 6

NEW PLYMOUTH POWER

SERVICE IMPROVEMENT TRANSFORMERS USED INCREASING DEMAND MET New transformers which have been installed at the Public Works Department's sub-station at Mangorei were connected to the supply yesterday, and henceforth the New Plymouth borough electricity department will be able to take sufficient power from the Government's bulk supply to meet all its requirements which have grown rapidly. A feature about the modern transformers installed is that the voltage can be changed under load, that is to say that the voltage can be raised or lowered without disconnecting the load so that should the voltage drop at any time it can be raised. Capacity Trebled. The transformers are of 7500 k.v.a. capacity, more than three times the capacity of the 2250 k.v.a. transformers, which they replace after 12 years' service. The transformers, of which there are four, are massive affairs contained in a metal tank standing about seven feet six inches in height and about five feet through by three feet wide. They weigh about 13 tons each, as each contains about 1000 gallons of special liquid whi 1 serves the dual purpose of insulation and cooling. Three of the transformers are coupled to forrn what is known as a "bank," while the fourth transformer is installed as a standby tor use in the event of one of the "bank" having to be cut out for overhaul. Since the end of July officials of the Public Works Department have been engaged preparing the transformers for their inclusion in the plant situated at the rear of the borough council's power station at Mangorei. The first step was to transfer the existing transformers to a temporary site and couple them up with the system so that the bulk supply could be maintained while the new transformers were being assembled and installed. Transformers Coupled Up. After being dried out the transformers were assmbled, tested and placed on their foundations in readiness for coupling up. Men engaged at the substation yesterday were employed coupling up the new transformers and disconnecting the old ones. By this means the change over from one bank of transformers to the other was accomplished in a few hours. The work of preparing and assembling the heavy transformers was greatly facilitated by the use of an electric crane capable of lifting 25 tons, which was installed in the transformer house, speci1 ally built for the assembling of the new transformers. When assembled the transformers were carried on a truck to special concrete pads or foundations on which they run on their own wheels.