ISLAMABAD, Aug 1: The Water and Power Development Authority has submitted a contingency plan to the government for overhaul of the system at Mangla Dam. According to Wapda, the auto transformers at Mangla power station are 38 years old and have been subjected to constant overloading for most of the time, thus reducing the life of the winding insulation.

“Two winding legs of one of the transformers have failed in the past on two occasions. Therefore, for such old equipment, provision of contingency is very much essential,” Wapda said. It said that the 132kv side units, after completing more than 316,000 operating hours over 38 years, were in need of ‘major overhauls’, involving shut downs for 6-8 months per unit, which could not be arranged with the existing two auto transformers.

Wapda said the overhauls required considerable funding for which donors, especially the World Bank and the Asian Development Bank, should be approached in addition to arranging local financing through the Annual Development Plan and the Public Sector Development Programme.

Overcoming the overloading of the existing two 138MVA auto transformers would improve system voltages in the adjoining areas and hence contribute to reduction of system losses, it said.

Wapda informed the federal authorities that there was not enough space for the construction of a 132kv bay in the existing 132kv switch yard of the power house. “So, the switch yard needs to be extended to provide space for at least two bays (including a space for a future bay). Beyond the existing fence there is a water drain and there is also need of cutting and filling of rocky land.”

Under the plan submitted by Wapda, foundations would be constructed for installation of the 220/132kv, 138MVA transformers, circuit breakers, isolators, CTs, PTs and gantries for double bus bars, etc.

It said the plan involved only addition of the third 220/132kv, 138 MVA transformer at existing 220kv Mangla switch yard. “There are no major governance issues of the power sector for the execution of the project,” it said.

Wapda believes that another 138MVA, 220/132kv auto transformer at Mangla power station is urgently required.

The plan would reduce overloading, increase system reliability, meet growing load demand and increase reliability of power supply for the areas fed from the power station in future, it said.