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. -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/ ------------------------------------------------------------------------------ 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=278785111&iu=/4140 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
