INSTALLATION
A cool air supply must be provided for transformers installed in a closed cell. The air flow should be 3.5 mc per minute for each KW loss, which corresponds to an air temperature rise of approximately 12ƒ C. The required duct cross-section for the air-inlet and air outlet openings can be obtained by the diagram of fig. 1. The required cross-section is calculated by the following formula:
where:
Sc = Cross-section
of air-inlet or air-outlet duct in sq.mt
P = Transformer losses in KW
H = Distance between the axis of outlet opening and the centre line of
transformer.
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Fig.
1 Diagram for the calculation
of inlet or outlet air cross-section |
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Fig.
2 Transformer typical indoor installation
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Oil
filled power transformer Cesi's
Short Circuit |