CURRENT-LIMITING REACTORS 461 



For Example: A 5 per cent reactor in a 60-cycle, 6600-volt, 

 100-amp., single-phase circuit, means that the reactor will have a 

 drop of 5 per cent, or 330 volts, when the rated current is flowing. 



The rating of the reactor will be as follows: 



C.L.S. 60 (cycles), 33 (Kv.A.), 330 (volt drop), 100 (amperes) 

 reactor to give 5 per cent reactive drop in a 660 

 Kv.A., 6000 volt single-phase circuit. 



In the case of three-phase circuits the percentage drop is 

 always based on the voltage between line and neutral. 



For Example: A 5 per cent reactor in a three-phase 60-cycle, 

 6600-volt, 100-amp. circuit means that each reactor (of the three) 



will have a drop of X 0.05 = 191 volts when normal current is 



V3 



flowing. 



The rating will then be as follows: 



C.L.S. 60 (cycles), 19.1 (Kv.A.), 191 (volts drop), 100 

 (amperes) reactor to give 5 per cent reactive 

 drop in 1145 Kv.A., 6600-volt three-phase circuit. 



Rating as Affected by Frequency. A reactor designed for a 

 given frequency may be used in a circuit of different frequency, in 

 which case the per cent reactance is approximately equal to the 

 ratio of the frequency for which it is to be used to the frequency 

 for which it is designed times the per cent reactance for which 

 it is designed. 



For Example: A 3J per cent 25-cycle reactor may be used in a 

 40-cycle circuit, in which case the per cent reactance is approxi- 



40 



mately X3J=5.6 per cent. 

 25 



Rating as Affected by Voltage. A standard reactor can be 

 used for lower voltage circuits than those for which it is designed, 

 in which case the per cent reactance is increased in the ratio of the 

 voltage for which it is designed to that for which it is to be used. 



For Example: On an 11,000-volt three-phase circuit requiring 

 the introduction of about 3J per cent reactance, it will be possible 

 to use a 13,200 volt 3J per cent reactor. The reactance will be 



Rating as Affected by Current. A standard reactor may be 

 used for lower currents than that for which it is designed, in 

 which case the per cent reactance decreases with the ratio of the 



