Hi Dan, I think the waveform problem Ray describes can most likely be resolved by installing a filter capacitor at the AC input terminals of the heat pumps. A small film cap (1 or 2 uF?) will function with the resistance and inductance of the branch circuit wiring to create a low-pass filter that will soften up those sharp edges of the 60 Hz waveform and provide a much cleaner zero crossing.
There's a huge difference between installing a small cap for filtering purposes and installing a large capacitor (or capacitor bank) to try and correct a lagging power factor. Might be worth a check-in with Outback tech support to get their blessing with this approach, but it should be a cheap and effective fix. Cheers, Mike Sullivan Solar Design Crestone, CO > From: Ray Walters <r...@solarray.com> > To: RE-wrenches <re-wrenches@lists.re-wrenches.org> > Subject: Re: [RE-wrenches] Mitsubishi Mini Split fighting with Outback > VFX Off Grid > Message-ID: <54469693.9070...@solarray.com> > Content-Type: text/plain; charset="iso-8859-1"; Format="flowed" > > The Outback is not a perfect Sinewave. It still has tiny steps in the > wave, and when electronics have a problem, its usually with the wave > form as it crosses zero voltage . Instead of being instantaneous, it > has a few milliseconds of time the wave is at the zero crossing, which > can drive some electronics nuts. I don't understand the issue beyond > that, but apparently the electronics use the zero crossing for timers > and synchronizing, and they're looking for an instant "click", not a smear. > Do the heat pumps work with the generator? Even though generators can > have more harmonic distortion, they do usually have a clean zero crossing. > If this is the case, I'm afraid I don't have a cure. We used to use > capacitors, but Dan from Exeltech just poo pooed that fix in another > recent thread, so I don't have any other tricks up my sleeve. > > R.Ray Walters > CTO, Solarray, Inc > Nabcep Certified PV Installer, > Licensed Master Electrician > Solar Design Engineer > 303 505-8760 > >> On 10/21/2014 8:54 AM, d...@foxfire-energy.com wrote: >> Anyone else had issues with Mitsubishi Mini Split heat pumps fighting >> with Outback VFX off grid inverters? Everything is brand new. Outback >> VFX7248, three separate heat pumps. The heat pumps shut down reporting >> multiple / confusing input commands. The heat pump guys want to blame >> the power system. I'm thinking bad Sushi. Thanks db >> >> >> Dan Brown >> Foxfire Energy Corp. >> Renewable Energy Systems >> (802)-483-2564 >> www.Foxfire-Energy.com <http://www.Foxfire-Energy.com> >> NABCEP #092907-44 >> _______________________________________________ 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
