From: Les N. <les...@fa...> - 2012-05-31 17:56:44
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Are the servo drives 3-phase as well? If not it may be cheaper to replace the spindle drive with one that is a bit less touchy. My Colchester Triumph 2000 CNC lathe has an inverter designed to run off 415V 3-ph. I use a step-up transformer to take my 230V single phase mains up to 415V single phase. I just feed two of the phase inputs and leave the third unconnected. You do need to derate the inverter if you do this as it stresses the filter capacitors and input rectifier. I never use full spindle power (10hp) so I get away with using the original inverter. I also need to limit the spindle acceleration in top gear with a 10" chuck otherwise I blow my main fuse. This setup has been working for 2+ years with no problems. Another, rather expensive, solution is to use an inverter plus a sinewave filter. This produces almost perfect 3-phase. These inverters are 240V in, 415 out but I am sure they are also available 110V in or whatever your local voltage is. <http://stores.ebay.co.uk/Drives-Direct-Inverters-LTD/DIGITAL-240-TO-415-INVERTERS-/_i.html?_fsub=5&_sid=60949062&_trksid=p4634.c0.m322>. The sine wave filters clean up the inverter output and output a waveform that is nearly as clean as proper 3-ph mains. > It is possible the DC filter caps are going out, and > replacing these caps would make it run reliably even as is. That is a possibility that is worth investigating. Some drive manufacturers even recommend changing these periodically. Les On 31/05/2012 18:27, Jon Elson wrote: > The sagging of the A-C voltage under load and the trip when starting the > lathe > point in the same direction. If the Simodrive has individual sensing of > each > line, it may be detecting that one is too low. Otherwise, it may be > detecting > too much ripple on the DC bus, as it doesn't get much charge from the > sagged line. It is possible the DC filter caps are going out, and > replacing these > caps would make it run reliably even as is. > > Jon > |