While inverters are supposed to work this way, and do so very well on the grid, have any inverters been formally TESTED with various generators to confirm the theory?
Anecdotes and theories are not enough. Until there are TESTS and guarantees from inverter manufacturers that expensive generator control boards will not be damaged, I would err on the side of caution. Get a waiver from your customer if they insist you connect on the load side of the generator transfer switch. I doubt you will get an independent P.E. to sign off on it and take the liability. I could be wrong, but........ why risk it? Jason Szumlanski Fafco Solar http://fafcosolar.com -----Original Message----- All, If the grid-tie inverter is operating under UL1741 (and therefore IEEE1547), then the inverter has to cease output within 1 second of the voltage going over 10% of the base voltage. So in the case where the generator is outputting and the load is less than the inverter output, the voltage will rise and the inverter will cease to ouput. The voltage will then drop, the inverter will reconnect, and the cycle will repeat itself. That assumes the generator's waveform is clean enough for the inverter to connect to in the first place. James Worden from Solectria Renewables covered this briefly in a SolarPro article: http://solarprofessional.com/article/?file=SP2_5_pg16_QandA_2. - Mike -- Michael Kelly Project Manager / Project Engineer NABCEP Certified Solar PV Installer ? SolarFlair Energy, Inc. 11 Mayhew Street Framingham, MA 01702 Direct Mobile: 617-899-9840 Main Phone: 508-293-4293 Main Fax: 508-293-4003 m...@solarflair.com _______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options & 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
