Trust me when I tell you that all of the line side conductors and taps are likely fine. It is unequivocally the switch contacts that are the issue. That said, I usually replace the conductors when there is any indication of overheating near the terminals. I have seen discolored copper, but it never gets bad enough to melt insulation.
Jason On Tue, Nov 2, 2021, 12:28 PM Dave Tedeyan <d...@sungineersolar.com> wrote: > It is always the left fuse! Thanks all for the pointers. I'll double check > the monitoring, but am thinking that I will be replacing the switch with a > SQD, and replacing the taps and AC wires as well while I'm at it. > Cheers, > Dave > > On Mon, Nov 1, 2021, 9:13 PM Jerry Shafer <jerrysgarag...@gmail.com> > wrote: > >> Bad switch >> >> >> On Mon, Nov 1, 2021 at 5:44 PM Jason Szumlanski < >> ja...@floridasolardesigngroup.com> wrote: >> >>> See attached image. Notice the discoloration on the top of the left >>> fuse. It's always the same thing, same place. >>> >>> Jason >>> >>> On Mon, Nov 1, 2021, 8:30 PM Jason Szumlanski < >>> ja...@floridasolardesigngroup.com> wrote: >>> >>>> I should also mention that it has nothing to do with ambient heat. This >>>> has occured in all seasons and with disconnects in direct sunlight on a >>>> south wall and disconnects in air conditioned garages. >>>> >>>> It's just a garbage product. We switched to Square D for 60A D222NRB >>>> fusible disconnects and are also using their 100A circuit breaker >>>> enclosures which are cost effective. The D223NRB is also a good fusible >>>> disconnect, but pricey. >>>> >>>> Jason >>>> >>>> >>>> On Mon, Nov 1, 2021, 8:24 PM Jason Szumlanski < >>>> ja...@floridasolardesigngroup.com> wrote: >>>> >>>>> It's the disconnect. We had dozens of this subpar disconnect design >>>>> fail on Enphase systems. The 2 Pole has the same issue. >>>>> >>>>> GE gave us some nonsense answer that it's General Duty and not >>>>> designed for continuous high power. Even 40A combined Enphase systems will >>>>> blow a 60A fuse. >>>>> >>>>> What you will find is the fuse will blow on one side and then >>>>> replacements will blow at decreasing intervals until it blows daily. Our >>>>> experience is the left side (of the 2-pole) is far more problematic for >>>>> some odd reason. It's not the fuse brand either. >>>>> >>>>> I believe the design fault is how the blades only hit a single contact >>>>> on one side when they close. The Square D alternative has the blade >>>>> slipping between two contacts. >>>>> >>>>> Sadly we have had to replace so many of these and most are supply side >>>>> interconnections, which make it tricky and expensive. >>>>> >>>>> Jason Szumlanski >>>>> Florida Solar Design Group >>>>> >>>>> >>>>> >>>>> >>>>> On Mon, Nov 1, 2021, 4:26 PM Dave Tedeyan <d...@sungineersolar.com> >>>>> wrote: >>>>> >>>>>> Hi All, >>>>>> >>>>>> I am servicing a system that keeps blowing fuses on the AC side, >>>>>> although it >>>>>> appears that everything is sized correctly. It is a SolarEdge >>>>>> SE11400A-US inverter. >>>>>> Max continuous output current is 47.5A x 1.25 = 59.4A. There is a GE >>>>>> TG3222R >>>>>> 60A AC disconnect, and it is wired up with #6 THHN wire. The >>>>>> terminals were tight >>>>>> and there was no evidence of arcing or burning in the past. This is >>>>>> indoors, and not >>>>>> exposed to sunlight. No extra conductors are in the conduit. >>>>>> >>>>>> But they say that they need to replace a fuse roughly once per month. >>>>>> Has anyone >>>>>> seen this before? Could there be some kind of fault in the inverter >>>>>> itself that >>>>>> occasionally induces extra current? Is there any way to tweak the >>>>>> settings so that it >>>>>> actually produces a bit more than 11.4kw? I appreciate your thoughts. >>>>>> >>>>>> Cheers, >>>>>> Dave >>>>>> >>>>>> -- >>>>>> [image: Logo] <https://www.sungineersolar.com/> >>>>>> Dave Tedeyan, P.E. >>>>>> Owner | Sungineer Solar >>>>>> p: he | him | his >>>>>> a: 1653 Slaterville Rd. | Ithaca, NY 14850 >>>>>> w: www.sungineersolar.com <http://www.sungineersolar.com/> >>>>>> c: (607) 288-2898 >>>>>> _______________________________________________ >>>>>> List sponsored by Redwood Alliance >>>>>> >>>>>> Pay optional member dues here: http://re-wrenches.org >>>>>> >>>>>> 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 >>>>>> >>>>>> There are two list archives for searching. When one doesn't work, try >>>>>> the other: >>>>>> https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ >>>>>> http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org >>>>>> >>>>>> List rules & etiquette: >>>>>> http://www.re-wrenches.org/etiquette.htm >>>>>> >>>>>> Check out or update participant bios: >>>>>> http://www.members.re-wrenches.org >>>>>> >>>>>> _______________________________________________ >>> List sponsored by Redwood Alliance >>> >>> Pay optional member dues here: http://re-wrenches.org >>> >>> 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 >>> >>> There are two list archives for searching. When one doesn't work, try >>> the other: >>> https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ >>> http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org >>> >>> List rules & etiquette: >>> http://www.re-wrenches.org/etiquette.htm >>> >>> Check out or update participant bios: >>> http://www.members.re-wrenches.org >>> >>> _______________________________________________ >> List sponsored by Redwood Alliance >> >> Pay optional member dues here: http://re-wrenches.org >> >> 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 >> >> There are two list archives for searching. 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