Tyree recently completed the supply of three 50kV/11kV, 12.5MVA ONAN power transformers to Eastland Network.
Eastland Network is the electrical utility company who owns, operates and maintains the electricity distribution network and transmission lines for Gisborne, Wairoa and the East Coast of New Zealand’s north island.
The transformers incorporated on-load tap changers and were designed & tested to verify emergency cyclic overload ratings. The long term cyclic overload rating was proven by test to be 18.75MVA at a nominal ambient of 15°C with a maximum winding hotspot temperature of less than 115°C, with the short term cyclic overload rating of 18.75MVA at an ambient of 15°C with a maximum hot spot temperature of less than 125°C and top oil temperature of 115°C.
The delivery of the units were challenging with the SH2 road closed due to a major land slippage at the Waioeka Gorge. Tyree Field Service team and NZ representative Neil Wech were able to manage the situation with the transporter, NZTA and local cranage companies to maintain the delivery schedule for Eastland Network. Despite the access challenges the three transformers were fully assembled, filled and tested successfully within a week of delivery.
The units have all been moved into there final locations, are energized and in active service where they will operate for their design life of 40+ years