Posted 28 October 2005 - 07:57 PM
There is a SEW 3 phase 1.5kw motor & gearbox running at 100hz via a danfoss 315 inverter. The current is fluctuating between 1.1a & 2.3a with no load but when the motor is running @ 50hz the current is stable @ 1.8a. The company which installed this says this is normal and this motor can run at 100Hz constantly. Is this true as I do not believe them.
Posted 29 October 2005 - 02:44 AM
Posted 29 October 2005 - 07:17 PM
Posted 31 October 2005 - 02:05 AM
If it is unloaded (as in open shaft) the current may be irratic as well. Check it again with the intended load.
Running at 100Hz may or may not shorten the motor life, it depends on the motor design. For instance if the motor base speed is 1450RPM, and you have bearings rated for 3500RPM, then there is no problem. But if the motor base speed is 3500RPM and the bearingas are rated only for that, then you are spinning at 7000RPM, your bearing will likely fail faster. Also, cooling fans may become ineffective at higher speeds, bearing lubrication may cease to function etc. etc. If SEW says it is OK however, it probably is because they have already considered these issues.
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