80 MVA bell tank type

Another important milestone in the history of SEA has been reached during the second part of 2016. 
It was the first delivery of such type big unit from the new plant for the liquid immersed power transformers
The scope of project was the replacement of an old transformer including the design, manufacturing, testing, transportation, off-loading and commissioning of the new one on site of Pontresina (Switzerland).

Below some images of the old transformer replaced by SEA after a detailed site analysis made one of its technicians.


Some electrical features of the transformer manufactured in the Factory Site of Tezze di Arzignano (VI) - Italy:

Power Rating: 80 MVA with ONAN cooling
Primary Voltage: 160 kV
Tapping Regulation: ± 9 x 1,55 kV by OLTC
Secondary Voltage: 55 kV

From mechanical point of view, it was necessary a detailed calculation related to the bearing structure of the transformer: the entire active part of it was shipped by truck without the belt cover that have been successfully applied on site in a second step.

In the following picure the construction of the basement of the bell tank.



The shipment without bell tank cover was due to the route from Italy to Swiss site through the Alps: a huge pre-analysis of each street from Vicenza to Pontresina REPOWER Plant was necessary in order to evaluate in the better possible way all the critical issues like underpasses, bridges, etc.
This analysis had a direct impact on dimensional features of the transformer.


The most critical part was along the road stretch from Tirano passing by the Bernina's Pass close to White Lake on top of Swiss Alps Mountain to Pontresina.

Some adding details of the project:

·        27 skilled people involved

·        806 working hours in technical department

·        28 suppliers involved

·        1998 working hours during the entire production process

·        7 trucks to site

All the operations were scheduled in a very detailed way and performed on time with the final energizing of the transformer positively carried out during the first week of October in the plant owned by REPOWER.

20 days site of activities were necessary for the complete the reassembling of the tank and to perform the site tests. 

With the sound pressure level Lp (A) of 48 dB (A) at 0.3 mt was reached another goal in this project........in order to respect "The sound of the Nature": another important "successful story" marked SEA.