18 Froceedmgs of the Royal Society of Victoria. 



If Pg be the capacity of the transformer as usually rated on 

 non-inductive load, then PaCos^ will be its capacity on an 

 inductive load of power factor Cosc/), as for this output we 

 get approximately the same secondary current as before. 



Hence we see from the preceding formula that if X=Ttan-^ 



the regulution for loads whose power factors are less than Cosi// 

 is better than that for non-inductive loads. 



If the load has capacity then ^ is negative, and the capacity 

 effect in reducing the drop or even producing a rise in voltage 

 with load can easily be deduced from the general expression for 

 the drop given in § 20. 



22. When the percentage drop of a transformer for a non- 

 inductive load Pj is known, we can by means of the formula in 

 § 20 calculate the sum of its leakage coefficients. 



For a non-inductive load — 



Drop(p.c.) = 100j.|T+(T^+^l')^ | 



P 



wherein this casej = p- 



As Po is the power absorbed on open secondary divided by the 

 power factor of the transformer on open secondary it can be 

 determined. It has been shown in § 7 how to practically 

 determine tj, and t^ can be obtained from tj as follows : — 



"I 



-'=^\ (§ 6). 



ri and r, can be measured and 

 «i Primary volts 



(§ 19)- 



«2 Secondary volts on open secondary 



Hence substituting in the above equation the values of j', T, 



and the drop, X or Xi + x.^ can be found. 



It is obvious that we can also by means of the general formula 



11 , , 



in § 20 determine both x^ + x^ and - -f - for any transformer from 



observations of the voltage drop for loads with different power 



