If the three phase power supply has {HEAD ~ a three wire connection}, the leads of the three phase power supply are coupled to {TAIL ~ two sets} of three star coupled resistors having different resistance values 
If the three phase power supply has { HEAD ~ a three wire connection } , the leads of the three phase power supply are coupled to { TAIL ~ two sets } of three star coupled resistors having different resistance values
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH