Damaging a mini-split heat pump has happened from this at a home in Florida. Hard always to prove as anything connected to the grid can be surge damaged also. Fujitsu did pay the warranty repair but would not if it happened again.
In cases where I have been approached to AC couple, I just recommend using the Schneider or Morningstar 600V controller and deselect the grid inverter solar/select the mppt. The battery inverter gets a programmed charge from the grid every 2 weeks and is ready to go drive the sub panel. Tesla says they are going to build an "offgrid" type battery which I assume to mean that it will not require AC coupling like the current models do. Dave Angelini Offgrid Solar "we go where powerlines don't" http://members.sti.net/offgridsolar/ e-mail [email protected] text 209 813 0060 > Hi Mac > > Thanks for mentioning this, Iâve wondered about it a lot. > Maybe someone whoâs a motor or electronics expert can chime in about > what potential damage can occur. Electronics, motors, VFDâs, are used to > seeing voltage +/- by a fair amount, but frequency is rarely off by more > than a fraction of a percent. > > > If the frequency shift is doing nothing more than turning the GT inverter > off ( no stepped regulation) then why do that vs relay? It still makes for > a 5 minute delay on restart, correct? > > Thx > Jay > > > > > >> On Feb 15, 2018, at 7:48 AM, Mac Lewis <[email protected]> wrote: >> >> Hi Wrenches, >> >> I just wanted to report that some electronics will fail and burn up >> during frequency shift. We have an off-grid Sunny Island system (60-62 >> Hz operating frequency) and we experienced sensitive electronics burning >> up during these events. Its been too long since this happened to tell >> you exactly what burned up. I think it was some HVAC controls. >> >> If its possible, I'd suggest a relay that opens up the grid-tie inverter >> as opposed to waiting until frequency shift is necessary. A >> well-specified relay can be highly reliable and not very expensive. >> >> Thanks >> >>> On Tue, Feb 13, 2018 at 11:26 AM, Glenn Burt <[email protected]> >>> wrote: >>> An installer I have been working with here in southern VT has also >>> repeatedly applied to become an installer with Tesla for powerwalls >>> with no response. >>> I cannot in good conscience recommend their products based on their >>> history and unresponsiveness in our area. >>> They may be great for Puerto Rico, and now Australia, but have >>> currently rated a thumbs down here. We are happy with the sonnen >>> product, delivery and support. >>> >>> Glenn >>> Sent from my 'smart' phone so please excuse spelling and typographical >>> errors. >>> >>> ------ Original message------ >>> From: Dave Tedeyan >>> Date: Tue, Feb 13, 2018 11:35 AM >>> To: RE-wrenches; >>> Cc: >>> Subject:Re: [RE-wrenches] experience with the Tesla Powerwall >>> >>> I think that this may have come up before, but I do not remember there >>> being a resolution: >>> Do you guys have any tips on becoming a Tesla dealer? We have people >>> ask about it all the time, but we have not been able to get Tesla to >>> respond. We have installed Sonnen, which is also a great system, but >>> the up front expense scares many people away. We are located in upstate >>> NY which may have something to do with it. >>> >>> Cheers, >>> Dave >>> >>> >>> -- >>> >>> Dave Tedeyan >>> Senior Engineer >>> >>> Taitem Engineering, PC >>> 10 Verizon Lane, Lansing, NY 14882 >>> Voice: (607) 930-3481 x6 >>> www.taitem.com >>> >>>> On Tue, Feb 13, 2018 at 10:36 AM, August Goers <[email protected]> >>>> wrote: >>>> Marco, >>>> >>>> Thanks for sharing, it is good to hear details from an installer who >>>> is living with a Powerwall. We starting selling the Powerwall 2 in >>>> 2017 and have worked up a large pipeline. We have about 20 installed >>>> so far, but are still waiting on utility permission to operate which >>>> is taking a long time. We have spent a good deal of time commissioning >>>> and testing each system. For the most part, our experience has been >>>> good although the commissioning software and internet connectivity >>>> features have been buggy. Hopefully those are issues that will be >>>> ironed out by Tesla. Otherwise, we've had the systems correctly >>>> operate in on-grid and off-grid modes with both Sol aredge and >>>> SunPower Equinox AC coupled systems. >>>> >>>> We installed conventional lead acid battery backup systems for over 10 >>>> years and I can confidently say that Tesla's Powerwall and Gateway >>>> setup is truly market-disruptive. The design flexibility of the >>>> Gateway setup, the small size, minimal labor to install, and >>>> performance blow other systems out of the water. I hope that other >>>> manufacturers are able to catch up with this type of design. >>>> >>>> Best, >>>> >>>> August >>>> >>>> August Goers >>>> >>>> Luminalt Energy Corporation >>>> >>>> o: 415.641.4000 >>>> >>>> www.luminalt.com >>>> >>>> >>>> >>>> >>>>> On Sat, Feb 10, 2018 at 12:23 PM, Marco Mangelsdorf >>>>> <[email protected]> wrote: >>>>> Aloha Wrenches, >>>>> >>>>> I thought I'd share my own experiences with the Powerwall as my >>>>> company is now launching a program to add PW to existing NEM systems >>>>> since the vast majority of them do not have storage which means that >>>>> if the grid goes down, so does their PV system. (With the exception >>>>> of the SMA SB line and their Secure Power Supply.) >>>>> >>>>> And no, I'm not a shill or toadie for Tesla. >>>>> >>>>> marco >>>>> >>>>> I wanted to walk my own talk. Before we launched adding Powerwall to >>>>> existing Net Energy Metered solar electric systems, I wanted to make >>>>> sure that what was promised on paper would work in the real world. I >>>>> added Powerwall to my NEM system last year and have been monitoring >>>>> and testing it during normal grid-on and grid outage modes. And >>>>> Iâm very pleased to report that Powerwall has performed flawlessly >>>>> and as expected. >>>>> >>>>> >>>>> >>>>> When used in a NEM system, Powerwall is programmed to be in >>>>> âBackupâ mode. When utility power is on, Powerwall stands ready >>>>> in a full state of charge for any power outage. During normal >>>>> grid-on conditions, my Powerall takes about .6 kilowatt-hours every >>>>> other day to stay fully charged. Over the course of the month, this >>>>> Powerwallâs electricity consumption comes to about 9 kWhs or about >>>>> $3/month at the current HELCO R rate. >>>>> >>>>> >>>>> >>>>> I have turned the utility power off to my home on a number of >>>>> occasions in order to experience how Powerwall would perform in a >>>>> simulated grid outage. When the grid goes down, my house effectively >>>>> becomes a self-generating micro-grid. That is, my photovoltaic >>>>> system (solar modules and inverters) and Powerwall (battery storage >>>>> and integrated inverter) form a power grid with energy being created >>>>> and stored and then consumed by my electric loads. >>>>> >>>>> >>>>> >>>>> Several things I noted from my simulated grid outages: >>>>> >>>>> · I purposefully overloaded Powerwall by turning on my >>>>> electric dryer and electric oven at the same time. As expected, >>>>> since the maximum output of Powerwall is 5 kilowatts, it shutdown. >>>>> Meaning that all the power in my house went off. Within seconds, >>>>> Powerwall reset itself and the power came back on, with the dryer and >>>>> oven having shut down after the power went off. If power does not >>>>> come back on after your Powerwall trips off, you will need to turn >>>>> off those high-power loads and reset Powerwall by turning its black >>>>> on-off switch, located on the right side of the unit, from on to off >>>>> and then on again. The important takeaway: during a utility outage, >>>>> you will need to be careful as far as operating heavy electric loads, >>>>> especially 240 volt appliances both from the perspective of >>>>> overloading your Powerwall and rapidly drawing down the battery >>>>> capacity, especially at night. >>>>> >>>>> · The magic of frequency shifting. Without getting into too >>>>> much techno-talk, this is the story of frequency shifting. Normal >>>>> utility frequency is 60 hertz (Hz). PV inverters require the utility >>>>> frequency to be at or near 60 Hz in order to operate. During a grid >>>>> outage, Powerwall effectively establishes grid quality power (120/240 >>>>> volts at 60 Hz), allowing a micro grid to operate with solar >>>>> providing power to your house loads (during daylight hours) and >>>>> charge Powerwall as needed. During the day with the loads being met >>>>> by your PV system and Powerwall being at or near full state of charge >>>>> (97-100 percent), Powerwall will shift the frequency from 60 to 66 Hz >>>>> in order to turn off the PV inverter(s). That is, the PV inverter(s) >>>>> see the frequency out of spec and shut down as theyâre expected and >>>>> required to do. Why? Because with Powerwall at or near full and the >>>>> house loads being met, thereâs nowhere for any additional solar >>>>> generation to go. Powerwall will wait for its the state of charge to >>>>> drop below 96-97 percent before shifting the frequency back to 60 Hz >>>>> which allows the PV system to restart and generate solar power again. >>>>> This frequency shifting can take place repeatedly over the course >>>>> of the day depending on load demands, solar potential and Powerwall >>>>> state of charge and is perfectly normal and does not damage the PV >>>>> inverters. >>>>> >>>>> · 66 Hz and home appliances: when Powerwall is at 66 Hz, >>>>> some of your house loads may be affected. What I and other Powerwall >>>>> owners have noticed, while not a comprehensive list, can include: >>>>> electronic clocks running fast, motors sounding different (microwave, >>>>> washing machine, pumps), uninterruptible power sources (UPS) not >>>>> charging and going into back-up power mode, appliances having a >>>>> computer behaving unusually. >>>>> >>>>> >>>>> _______________________________________________ >>>>> List sponsored by Redwood Alliance >>>>> >>>>> List Address: [email protected] >>>>> >>>>> Change listserver email address & settings: >>>>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >>>>> >>>>> List-Archive: >>>>> http://www.mail-archive.com/[email protected]/maillist.html >>>>> >>>>> List rules & etiquette: >>>>> www.re-wrenches.org/etiquette.htm >>>>> >>>>> Check out or update participant bios: >>>>> www.members.re-wrenches.org >>>>> >>>>> >>>> >>>> >>>> _______________________________________________ >>>> List sponsored by Redwood Alliance >>>> >>>> List Address: [email protected] >>>> >>>> Change listserver email address & settings: >>>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >>>> >>>> List-Archive: >>>> http://www.mail-archive.com/[email protected]/maillist.html >>>> >>>> List rules & etiquette: >>>> www.re-wrenches.org/etiquette.htm >>>> >>>> Check out or update participant bios: >>>> www.members.re-wrenches.org >>>> >>>> >>> >>> >>> _______________________________________________ >>> List sponsored by Redwood Alliance >>> >>> List Address: [email protected] >>> >>> Change listserver email address & settings: >>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >>> >>> List-Archive: >>> http://www.mail-archive.com/[email protected]/maillist.html >>> >>> List rules & etiquette: >>> www.re-wrenches.org/etiquette.htm >>> >>> Check out or update participant bios: >>> www.members.re-wrenches.org >>> >>> >> >> >> >> -- >> >> >> >> Mac Lewis >> >> "Yo solo sé que no sé nada." -Sócrates >> >> _______________________________________________ >> List sponsored by Redwood Alliance >> >> List Address: [email protected] >> >> Change listserver email address & settings: >> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >> >> List-Archive: >> http://www.mail-archive.com/[email protected]/maillist.html >> >> List rules & etiquette: >> www.re-wrenches.org/etiquette.htm >> >> Check out or update participant bios: >> www.members.re-wrenches.org >> > _______________________________________________ > List sponsored by Redwood Alliance > > List Address: [email protected] > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://www.mail-archive.com/[email protected]/maillist.html > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org > > Dave Angelini Offgrid Solar "we go where powerlines don't" http://members.sti.net/offgridsolar/ e-mail [email protected] text 209 813 0060 _______________________________________________ List sponsored by Redwood Alliance List Address: [email protected] Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/[email protected]/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
