Hello Marke and GGOSS
Marke : The health of the motor seems OK as insulation windings resistance taken with Megger shows a good Ohmic value. Continuity of stator coils also Ok as well as phase balance.
Regarding power supply being stiffened I dont think so anyone has done that to my knowledge...
shortstub : From aldighe
Thanks for yr reply. Answers to your queries
1) The installation is a 20 yr old one and the problem is new. Before motor would start up on the DOL starter drawing normal starting current. Now of late is tripping off on overload as starting current is abnormally high...
GGOSS, Marke and NNPackerfan
I am facing a similar problem with motor tripping on starting on the ship where I work. Only difference here is is on a DOL - direct on line starter. Motor is of 440V / 175 kW driving a centrifugal pump. Main bus bar is 6 kV and stepped down to 440V. During satring...