Actually at least the X200 and WJ200 have integral interal braking resistors- but, for practical reasons of space and cooling, they're undersized and only "remedial". They can't absorb the full current of high-speed braking that the drive can potentially deliver.
Danny On 3/13/2016 1:14 PM, Kirk Wallace wrote: > On 03/13/2016 10:39 AM, Jon Elson wrote: >> On 03/13/2016 08:47 AM, Gene Heskett wrote: >>> On Sunday 13 March 2016 09:30:30 John Thornton wrote: >>> >>>> I just used the the one for by the drive. I "think" not all drives >>>> would use the same resistor. Just looking at the GS2 and there are 12 >>>> different braking resistors. >>>> >>> All of which are $435 a copy & still need some sort of an extra, external >>> controller. AD thinks we are growing our own money on a tree in the back >>> yard? >>> >>> >> MOST VFDs have the switch transistor built into the power >> block. (6 rectifiers and 7 IGBTs). >> So, those only need the resistor added. The purpose-built >> braking resistors usually have a thermal overload sensor so >> the drive shuts down if the resistor overheats. >> >> Jon > > I haven't read back through this thread, so this may have been mentioned. > > I added generic (wire wound with aluminum case) resistors to my VFD > (Hitachi SJ200), but I still had fits trying to get a decent > deceleration. It turned out that I needed to set the duty register, > which is set to 0% by default. I think it is at 50% now and works a > treat. I have a PDF copy of the VFD manual so I did a keyword search on > "dynamic" to find all the settings that might affect braking, then went > through each one until I found the duty setting. There was another type > of braking, but it turned out to be a red herring. I seem to recall it > was "DC braking", which injects DC to the motor for slow speed braking > and doesn't use the braking resistor. One can hear the motor sing as the > motor comes to a stop when this feature is active. > > It seems one must find all of the ducks, pick the right ones, and put > them in a row before braking will work. > > ------------------------------------------------------------------------------ Transform Data into Opportunity. Accelerate data analysis in your applications with Intel Data Analytics Acceleration Library. Click to learn more. http://pubads.g.doubleclick.net/gampad/clk?id=278785231&iu=/4140 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
