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ELECTRICAL EQUIPMENT 



Oil-supply System. Many different schemes are used in 

 laying out the oil-supply system. The piping should, however, 

 always be arranged so that the transformers may be readily and 

 quickly drained for inspection and in case of emergencies. This 

 draining also refers to the piping itself. Storage tanks should be 

 provided for both filtered and unfiltered oil, and these are gener- 

 ally located in the basement. Sometimes they are installed in 

 compartments and occasionally the tanks are further imbedded in 

 sand as an additional fire protection. 



A flexible oil-piping system for a transformer installation is 

 shown in the diagram (Fig. 285). This system will allow the oil 



To Sewer 



i 



To Oil Switch Tanks* 



J L 



-Note:- In very large installations 

 where oil switches are not 

 located near transformers, a 

 delivery header for oil 

 switches is recommended 



Drain and Storage 

 Tanks below Floor 

 Level of Trans- 

 formers 



Oil Filter and Pump 



Located on Floor Level of Tanks 



Storage Tank for 

 Oil Switches 



FIG. 285. Diagram Showing Method of Arranging Transformer Oil Piping. 



to be circulated from any transformer to either tank; from one 

 tank to the other, either directly or through the filter press; and 

 finally, from either tank to the transformers, either directly or 

 through the filter press. A connection to the sewer or tailrace 



