Hey Mac, We have installed many Magnum inverters in power systems that use home standby (like the Generac), RV style and all kinds of portable generators and have never experienced this issue. I have a Scopemeter also and have seen far worse waveform distortions than you are showing in the photos so I believe your problem is not as simple as the sine waveform.
From the cost standpoint, I’de guess you have to try a different brand inverter first. However, since the problem only occurs with that particular generator, I would not trust it. Larry Crutcher Starlight Solar Power Systems On Jul 14, 2015, at 6:01 AM, Mac Lewis <maclew...@gmail.com> wrote: Hello wrenches, Last December I posted about a Magnum 4448 and a Generac 22 kW generator that aren't working well together. The symptom was that the Magnum transformer would overheat very quickly, even at very low charge rates (<2A DC). We have verified 120/240 VAC operation of the generator. We were able to get up to the site with an oscilloscope and see if we could find anything out. I've attached some photos of the oscilloscope output. I don't have anything to compare it to, so I'd like to see if anyone has some insight into why this may be occurring. The 4 photos are as follows (all photos L1-L2): 1. Generator Waveform No Load: Unloaded Generator Voltage Waveform 2. Charger 1st Connected: AC Input Voltage waveform immediately after charger connects 3. Steady State Operation Editted: AC Input Voltage waveform after about 10 seconds, this waveform continues until transformer overheats (in about 2 minutes) Note the disturbances. 4. Zoomed In Ripple: Closer view of the disturbances noted in #3. We have tried replacing the Magnum with an identical unit, and we had the same issue. We also tried a Honda 6500 with atrocious voltage and frequency regulation and it worked fine with the Magnum. Since I did not sell him the generator, the easy out is to replace the generator. However, there is some custom exhaust duct work and it will be much more expensive to replace the generator than to try a new inverter. I think that over all it is preferable for the client to replace the inverter/charger with a different brand. I have no problem doing that except that I'd like to be relatively sure that this is anomalous behavior between the Magnum and the Generac and not a generator issue. What are the chances that I'd have the same issue with a different inverter? What might cause this? All voltage and frequency measurements have been perfect with the Generac. Your comments or thoughts are appreciated. Thanks
_______________________________________________ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
