BrendanDixon
Member
Hi All,
Just looking for advice on a problem we are having. We have a crane hoist that had a Yaskawa G5 15Kw drive with a 15kw slipring motor(slip rings shorted). From what I understand is that a while back the G5 drive went faulty and was replaced, then a while later the motor was replaced with a 15kw Squirrel cage induction motor. A while after that I was called as the when lifting a load that was already suspended the motor would lose torque and run downwards. When looking at the drive I noticed it was an E7 drive which is meant for HVAC. I then stated that the drive was not the correct drive. we approached the company that supplied the drive and they say that the drive is an F7 with an E7 Cover(Apparently the agent did not have a complete assembled drive) and they say the problem is with the motor being changed to a low efficiency(89%) squirrel cage induction 15kw motor. According to the company that replaced the drive they say it was working fine before the motor was chnaged. talking to the guys for our company they do not know when the problem started as they say both were changed a long time ago.
My question is this with a the above situation can a slipring motor generate more torque than a squirrel cage induction motor?
Just looking for advice on a problem we are having. We have a crane hoist that had a Yaskawa G5 15Kw drive with a 15kw slipring motor(slip rings shorted). From what I understand is that a while back the G5 drive went faulty and was replaced, then a while later the motor was replaced with a 15kw Squirrel cage induction motor. A while after that I was called as the when lifting a load that was already suspended the motor would lose torque and run downwards. When looking at the drive I noticed it was an E7 drive which is meant for HVAC. I then stated that the drive was not the correct drive. we approached the company that supplied the drive and they say that the drive is an F7 with an E7 Cover(Apparently the agent did not have a complete assembled drive) and they say the problem is with the motor being changed to a low efficiency(89%) squirrel cage induction 15kw motor. According to the company that replaced the drive they say it was working fine before the motor was chnaged. talking to the guys for our company they do not know when the problem started as they say both were changed a long time ago.
My question is this with a the above situation can a slipring motor generate more torque than a squirrel cage induction motor?