Re: [RE-wrenches] Single phase to three phase interconnect
Eric, For a 6kW system on a reasonable size commercial service, it shouldn't be a problem to stack your 2 inverters on one or two legs of the 3-phase service. Loads are never perfectly balanced, so synchronous generators don't need to be either, up to a point. Ask the utility if you can feed the 6kW in on one leg. They'll look at their transformer for the service in question and make a decision. If they let you do it, just try to feed in on the most heavily loaded leg of the 3-phase service. Regards, -Hans From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Eric Thomas Sent: Monday, April 25, 2011 11:01 AM To: re-wrenches@lists.re-wrenches.org Subject: [RE-wrenches] Single phase to three phase interconnect While commercial solar work is newer to me, im surprised this hasn't been addressed very much in our forum: Interconnecting single phase inverters to three phase services. We are laying out a 6kW system using Silicon Energy Cascade modules and Aurora PVI inverters (either 2 or 3 PVI 3.0's). The challenge is finding a way to easily tie two of these inverters into the existing 3phase service. I've been reading up on Sunny Boys tech notes and on this forum about imbalance and such, but im still not comfortable enough with tie in. Due to the string configuration options, I can add a third inverter and use a three phase subpanel to aggregate the inverters then tie them in. But adding a third inverter seems like a goofy solution. In looking at available equipment, transformers, phase converters etc, I can't seem to find the right fit. Any ideas? This system does not have a three phase inverter option due to Made in WA req's. Thanks! Eric Thomas Solar Epiphany LLC ___ 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
Re: [RE-wrenches] Single phase to three phase interconnect
Eric, In order to connect single phase to three phase you probably need phase sensing on all three legs in order to disconnect the inverter from legs connected if one leg fails. Also, in Ontario under microFIT & FIT we typically have to balance power evenly across each leg as far as feeding power into grid on three phase. That is why utility companies basically require three phase inverters on existing three phase lines such as PowerOne or Fronius. If single phase is only available, you can connect single phase up to 100kW I believe (after connection impact assessment is done of course) Not allowing three phase inverters when three phase is available is a puzzle to me. Not very cost effective and overcomplicating the system. Thanks. Kind regards, Wilco Vercoelen President Dommelvalley Green Power - Solar Energy Solutions Barrie, Ontario Canada _ From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Eric Thomas Sent: April-25-11 14:01 To: re-wrenches@lists.re-wrenches.org Subject: [RE-wrenches] Single phase to three phase interconnect While commercial solar work is newer to me, im surprised this hasn't been addressed very much in our forum: Interconnecting single phase inverters to three phase services. We are laying out a 6kW system using Silicon Energy Cascade modules and Aurora PVI inverters (either 2 or 3 PVI 3.0's). The challenge is finding a way to easily tie two of these inverters into the existing 3phase service. I've been reading up on Sunny Boys tech notes and on this forum about imbalance and such, but im still not comfortable enough with tie in. Due to the string configuration options, I can add a third inverter and use a three phase subpanel to aggregate the inverters then tie them in. But adding a third inverter seems like a goofy solution. In looking at available equipment, transformers, phase converters etc, I can't seem to find the right fit. Any ideas? This system does not have a three phase inverter option due to Made in WA req's. Thanks! Eric Thomas Solar Epiphany LLC <>___ 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
Re: [RE-wrenches] Single phase to three phase interconnect
Eric, Marvin Hamon, a PE in CA, wrote an article for SolarPro magazine on this topic that may be of assistance: http://solarprofessional.com/article/?file=SP3_1_pg66_Hamon&search= David Brearley, Senior Technical Editor SolarPro magazine NABCEP Certified PV Installer david.brear...@solarprofessional.com Direct: 541.261.6545 On 4/25/11 1:01 PM, "Eric Thomas" wrote: > While commercial solar work is newer to me, im surprised this hasn't been > addressed very much in our forum: Interconnecting single phase inverters to > three phase services. We are laying out a 6kW system using Silicon Energy > Cascade modules and Aurora PVI inverters (either 2 or 3 PVI 3.0's). The > challenge is finding a way to easily tie two of these inverters into the > existing 3phase service. I've been reading up on Sunny Boys tech notes and on > this forum about imbalance and such, but im still not comfortable enough with > tie in. Due to the string configuration options, I can add a third inverter > and use a three phase subpanel to aggregate the inverters then tie them in. > But adding a third inverter seems like a goofy solution. In looking at > available equipment, transformers, phase converters etc, I can't seem to find > the right fit. Any ideas? > > This system does not have a three phase inverter option due to Made in WA > req's. > > Thanks! > > Eric Thomas > Solar Epiphany LLC > > > ___ > 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 ___ 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
[RE-wrenches] Single phase to three phase interconnect
While commercial solar work is newer to me, im surprised this hasn't been addressed very much in our forum: Interconnecting single phase inverters to three phase services. We are laying out a 6kW system using Silicon Energy Cascade modules and Aurora PVI inverters (either 2 or 3 PVI 3.0's). The challenge is finding a way to easily tie two of these inverters into the existing 3phase service. I've been reading up on Sunny Boys tech notes and on this forum about imbalance and such, but im still not comfortable enough with tie in. Due to the string configuration options, I can add a third inverter and use a three phase subpanel to aggregate the inverters then tie them in. But adding a third inverter seems like a goofy solution. In looking at available equipment, transformers, phase converters etc, I can't seem to find the right fit. Any ideas? This system does not have a three phase inverter option due to Made in WA req's. Thanks! Eric Thomas Solar Epiphany LLC ___ 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
