Thanks Darryl, For this test we were looking primarily at how the inverters handled the inrush current of a starting surge, and what affect that would have on voltage regulation of both the loaded and unloaded phase. I had heard anecdotal tales of earlier split phase inverter designs allowing the unloaded phase to spike wild under starting surges and we've all seen real world problems with inverters dropping voltage to keep the current up, so I wanted to see what would happen with the new XW and Magnum products. We also had the opportunity to have FX and SW products as a reference comparison.
We used simple power strips in order to get all the loads to make a coordinated starting spike, and all surge loads were on one phase. We locked the triggers in the on position, then turned on the power to all the loads with the power strip switch. Not high tech certainly, but effective and kept us on time and within budget ;-) We reached the limits of the turkey timer circuit breakers in the power strips before we reached the limits of the inverters or ran out of power tools. In future tests, I'll rig up a series of relays to allow us to push the limits further. The loads were standard contractor style equipment I hauled in from home. Chop saw -- Dewalt 12" compound miter saw, 15 amp 120v Planer -- Delta 12" planer, 15 amp 120v Routers -- Porter Cable 690's, 11 amp 120v, 1-3/4 hp Air compressor 1 -- Thomas T-30 pancake, 12.5 amp 120v, 1-1/4 hp Air compressor 2 -- Rigid stacked hot-dog, 14 amp 120v, but probably the second ugliest air compressor I've ever seen, from a starting surge POV. There were also a baseline load on both legs of two electric heaters, and we had two CF light bulbs for visual feedback -- it's one thing to look at squiggles on a scope, but sometimes the best feedback is seeing what is going to happen to the lights. Now I'm kicking myself, because we didn't try the same conditions using grid power. Oh well, next time. Battery bank was a single 48v string of 5 year old Surrette S460 batteries, with 4/0 cabling. Phil Undercuffler Director, Battery-based and Off-grid Conergy Sales & Systems, Americas Our World Is Full of Energy 1730 Camino Carlos Rey Suite 103 Santa Fe, NM 87507 [EMAIL PROTECTED] Direct | 505.216.3841 Toll Free | 888.396.6611 x4841 Fax | 505.473.3830 www.conergy.us -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Darryl Thayer Sent: Tuesday, August 19, 2008 6:57 PM To: RE-wrenches Subject: Re: [RE-wrenches] offgrid system question Thanks Phill, I have often thought that I should have compiled such a list from my experiances, but of course we are always to busy to do so. Could you add a few words to your post For the chop saw, type & manfactureer, and how was the surge attained? I assume it is just turning on of the saw no load at switch on? , or was it the peak as the saw cut onto the log. On the others similar and was the surge when one device was turned on? of the set? or were all turned on together? Another interestering datum would be what is the surge currents doing the same experiments using the grid. Thanks Darryl _______________________________________________ List sponsored by Home Power magazine [email protected] http://lists.re-wrenches.org/listinfo.cgi/re-wrenches-re-wrenches.org List rules & etiquette: http://www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
