THE HEATING OF TRANSFORMERS 



117 



In some investigations of transformer troubles in Germany I 

 once found an instance where the oil was kept in wooden barrels 

 in tin- open air. and in rainy weather pools of water collected on 

 the heads of the barn-Is and gradually worked through into 

 tin- oil. Under any such conditions, of course, the use of 

 oil is fatal, but with reasonable intelligence, great advantages, 

 chiefly a> regards cooling, attend the use of oil in transformers 



Centigrade 

 60, 



123456 769 10 U12 



4 curves of 7." -k\\ F. Iton-iiuillaumc-Lahmeyer transformer. 



14 i> 16 



Hour^ 



The curve in Fig. 78 gives a rough id.-a of the time which 

 will elapse for a 50-cydr oil-immcr>. -d t ran-foi -in. -r of repre- 

 MntfttlTe design to reach its ultimati- trni|MTaturc \\li.-n 

 operated at it- i-.-ii. ,1 l,,ad. (.r.nt variations exist, ho\\, 

 with variali.'i^ in tin- ir..j.,irii,,n>i and construction of the 

 tran>!.riiier. Very large rmtn n-ijuin- many liou- 



,n thrir iiltimat'- temperature. Tims ill,, tcii-p, latnre of 

 il-iumirr>rd ti-ai, it\ may c..ntinu- 



