The application of the motor is on a hydraulic lift.
Originally the unit had a 15hp motor. Line voltage is 485v 3 phase.
Someone at our company, decided to order a new pump unit, and ordered a unit with a 30HP 3phase motor. The motor runs fine when the lift is empty, or close to full load. When it gets up near full load the motor leads get hot, the amperage starts going off scale, the line voltage drops about 10 to 15 volts. The motor bogs down until the overload trips.
The warranty department/field engineering has told them to replace the motor, pump, valve, none have which have made a difference. They said the motor being larger wouldn't cause this. I guess they think the bigger HP motor is not being asked to do more work than the old
15hp motor, and should have no problems.The crew doing the work, asked me. My reaction was the motor is to big, install a 15hp or 20hp motor. My reason being is the wire going to equipment is to small, and is causing the voltage drops at higher current.
I'm asking for more opinions on this problem, and some insight on what is happening to this 30Hp motor.