liquid starter

hello everybody!
id pre-commisioned (instrumentation test) a brand new wound- rotor induction motor having a capacity of 3000KW. Ive seen its liquid starter cubicle, the question: Is this liquid starter, is put on the primary or in the secondary starting (id suspected on the secondary); please let me know? how the liquid starter alter its resistance? does it most likely the same principle of BRINE TANK TESTER for load testing of Electric generators?

surge testing

hello!
anyone who experience in balance impedance testing using surge comparison tester, id experience testing on 1.) DC armature winding with a rated armature voltage of 650V upon gradually applying the test voltage id notice at 250V, its wave signature distorts with tracking trace as shown on display but as i increase the the voltage over 250V it will then balance without distortion. is there something wrong in the winding? is there any test equipment that is more suitable for armature winding test? (its history has a pitch bar marking on commutator bars, no shorted nor open winding upon using growler) 2.) upon testing a 4160V (flat-wire coil) squirrel cage induction motor, id noticed a HISSING sound in the stator winding before its wave signature distorts to more chaotic trace. What makes this HISSING sound? Can anyone elaborate the occurrence of this phenomena, its posssible threat to the motor winding?

Thanks..


fbJavier