Hi Dan, I still have 4 Trace U series inverters in the field and have told these customers that they should be saving up for a new inverter for the last 10 years. Is there some preventive troubleshooting I could do before they potentially have the problem Drake is describing, or just die of old age? I have an O scope, but have never actually used it on Modified Sine Wave....
Thanks, Jason Lerner Waldron Power and Light Co. On May 20, 2014, at 7:54 AM, Exeltech wrote: > Hello Drake, > > As a professional electrial design engineer in the solar energy industry, I > can say without hesitation, the simple answer to your question is "Yes". > Waveforms can deterioriate as components age. Lower-quality capacitors will > dry out in 20 years' use (or less!), and this in turn can indeed alter the > waveform. You'd need at a minimum a good oscilloscope to observe the > waveform. If it's really ragged, and no longer stair-stepped, the inverter > is clearly suspect. If it resembles a "Pyramid", there may be another issue > afoot. > > Motors connected to modified square wave power turn at lower RPM and operate > [sometimes much] hotter than their sine-fed bretheren. Over time, the > increased heat takes its toll on the wire insulation in the motor, causing an > eventual breakdown of the insulation and a short-circuit of the windings. > Presto! Motor BBQ (sometimes inverter too). > > > By the way .. to use "quality" in context with reference to a modified square > wave is quite an oxymoron .. but in this case, it fits. > > > Dan > > -------------------------------------------- > On Tue, 5/20/14, Drake <[email protected]> wrote: > > Subject: [RE-wrenches] Modified sine deterioration > To: "RE-wrenches" <[email protected]> > Date: Tuesday, May 20, 2014, 9:24 AM > > Hello Wrenches, > > We are diagnosing a system with a 20 year old Trace DR 1512 inverter. > Recently a motor burned out that had been running on the system. I do > understand that modified sine (modified square) wave inverters are hard on > motors in general. > > My question is, "does the quality of the Mayan Pyramid sine wave deteriorate > with time as the capacitors dry up, or for any other reason? Would the power > quality be expected to have declined on an old unit like this? > > Thanks, > > Drake > > Drake Chamberlin > Athens Electric LLC > OH License 44810 > CO License 3773 > NABCEP Certified Solar PV > 740-448-7328 > http://athens-electric.com/ > > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: [email protected] > > Change email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > _______________________________________________ List sponsored by Home Power magazine List Address: [email protected] Change email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
