I have three phase motor wired high
I have three phase motor wired high
(OP)
I have three phase motor wired high voltage. (400v). Drive programmed 230.
Has run 24/7 times six weeks at 60 percent MAX speed. Found problem when new product setup required much faster speed.
A second motor, changed yesterday and incorrectly wired the same way gave no problem. What happened to motor running incorrectly 6 weeks. Just curious. The problem seen was on panel view amps showed 99 percent before fault. Most recent one never exceeded 25 perceny
Has run 24/7 times six weeks at 60 percent MAX speed. Found problem when new product setup required much faster speed.
A second motor, changed yesterday and incorrectly wired the same way gave no problem. What happened to motor running incorrectly 6 weeks. Just curious. The problem seen was on panel view amps showed 99 percent before fault. Most recent one never exceeded 25 perceny





RE: I have three phase motor wired high
RE: I have three phase motor wired high
I understand this was big screw up. But my curiosity is,, what did this mistake do to the motor being used for six weeks that showed up when increasing the speed
RE: I have three phase motor wired high
That said, as you increase the speed by raising the frequency the motor needs higher voltage to provide the horsepower demanded by the larger load caused by the higher speed. If the voltage isn't there it will draw more current to provide the volts x amps = Power needed. That means the motor will get over-currented and toast.
Typically the VFD will protect the motor from that but if the motor is miswired or the VFD protection setting are screwed up as suggested by the rest of this messed up install then the protection could easily be defeated. As long as the VFD is not itself being overloaded it will happily toast a motor.
Keith Cress
kcress - http://www.flaminsystems.com
RE: I have three phase motor wired high
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: I have three phase motor wired high
RE: I have three phase motor wired high
At 60% speed the motor still had enough torque to drive the load.
As the speed increased past 60% the load demanded more torque than was available at rated current.
Bill
--------------------
"Why not the best?"
Jimmy Carter