I spent the day swapping out the 15hp idler in the RPC for my 10hp idler (much quieter by far) and balancing the RPC per the directions in the Fitch pdf. I did notice that my Vac and Vbc was reversed from his chart no matter what I tried. In the end I had Vab 244, Vac 252, Vbc 252, Va 122, Vb 122, Vc 212 with c being the generated leg.
http://www.practicalmachinist.com/FitchWConverter.pdf I did a test run and it would take a S3000 M3 without an error, above that it would error out. Then I remembered that I had the taps wrong on the step up transformer. I changed them from 208 to 240 and it would error out at S2000. I moved the taps to the 220 lugs but ran out of time to test it. Just to recap a bit everything including the RPC is grounded to a common ground. The RPC does not have a neutral. The inputs to the machine are 3 phase + ground. The only neutral in the machine is from the step down transformer for the 120vac circuits. The Simodrive 611 is grounded to the same common ground. I won't have much time today but I'll try and test a few more things and gather up the part numbers and call the Siemens tech support line Wednesday to see what they say. I do have a small line reactor that I plan on hooking up just to scope what it might do. Line reactors are cheap compared to other options... Thanks John On 5/28/2012 12:37 PM, Jon Elson wrote: > John Thornton wrote: >> I've been searching for "isolation transformer" but they all seem to be >> 480 to 240 or similar. Not had any luck so far on finding a 240-240 >> transformer. >> > Many dry transformers that do 480 - 240 can be restrapped for > 240 -240. Also, voltage adjusting transformers can often be > set for 1:1 ratio. Especially in the delta-wye use where a > neutral needs to be derived from a delta substation. > > Still, I'm not sure this will solve your problem, if the phase > converter is unbalanced. I'd try to improve the balance first, > before adding another half ton box to your shop. > > Jon > > ------------------------------------------------------------------------------ > Live Security Virtual Conference > Exclusive live event will cover all the ways today's security and > threat landscape has changed and how IT managers can respond. Discussions > will include endpoint security, mobile security and the latest in malware > threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
