Thanks, everyone, for the quick and interesting replies. There is certainly plenty of information for me to investigate further.
@Jraef - Am I correct in thinking that the Rockwell VFD is what I would call a "standard" drive, it presumably has encoder input for the speed feedback?
From my...
Hi, All,
Does anyone have any experience of using a standard VFD to drive a linear motor? Or are you aware of any VFD's which will work with linear motors without a world of pain? Motor in question is 415V, 50Hz, 5m/s, 3A.
Thanks for the help in advance,
Mort
Most motor manufacturer's publish a de-rating curve for current relative to speed, from memory this begins at 15Hz - 20Hz. If it is a short-term state as described, then there probably won't be an issue.
Interestingly, this topic caused some conflict between the motor and VFD departments when...
Thanks, Gunnar, for explaining better than I could. I often struggle with technical explanations due to my total lack of a formal education - I went to Art College. :-)
Cheers,
Mort
Hi, Gunnar,
Thanks for the reply. I can only speak from my personal experience with our particular products, but it is a topic I have been doing some work on in the past few years. The following refers to small (<30kW) drives.
You correctly point out that there is only 1 temperature measurement...
Also worth considering that a 10K reduction in capacitor temperature will normally double their lifetime. So some thought about cooling, etc. could save a lot of money in the long term....
Cheers,
Mort
Caused a lot of grief at our end, particularly with the modular systems. A far more effective method of preventing uranium extraction would be to leave a back door in the plc software, tell mossad and the CIA how to exploit it, and get the centrifuges to overspeed until they destroy themselves...
Hi, all,
I was mooching through this thread and thought I would throw in my 2p/2cent:
In my limited experience, motors can be supplied with "415Vac" or "230Vac" on the brake rating plate, and as mentioned, this is usually an indication of the rectifier module fitted - the actual brake coil is...
Hi,
If the purpose of the test bed is to verify that the new VFD has been built correctly, and everything works as it should, then connecting the load motor to the mains is going to recover most of the energy back to the grid, and provides an easy-to-maintain solution. This is the method used in...
