Has anyone had issues with enphase tripping AFI circuits on the panel they are interconnected with? In this install the interconnection is a line side tap. Gary Easton Appalachian Renewable Power Systems NABCEP Certified Solar PV NABCEP Certified Solar Thermal 740-277-8498
> <DIV style="font-family:Arial, sans-serif; font-size:10pt;"><DIV>First, I > am not talking about NEC requirements for "arc fault" circuit breakers in > bedrooms!</DIV> > <DIV> </DIV> > <DIV>I hope those on the list who are licensed electricians are very > familiar with the safety issues of an "arc flash" but I have run into many > pv installers who do not have a clue, and believe as long as the breaker > they are working on is disconnected there is no danger when working with > the panel energized. This is a VERY dangerous problem and it can > happen on brand new or old electrical switchgear. An arc flash > starts with something across the buss bars of a breaker > panel or from a buss to ground. What is hard to understand is this > is not a true short circuit and will NOT trip any circuit breaker. > </DIV> > <DIV> </DIV> > <DIV>This makes it very dangerous when working on any energized > panel. It starts with any small or poor conductor across the phases > or buss bars. This could be anything from a fine wire, a dead > lizard, rust falling off the interior when you slam the door closed, > filings from drilling a hole in the panel side, or even removing or > installing a new or old circuit breaker even if it is not connected to any > load. This is just enough contact to allow an arc to form, and as > soon as the arc forms it goes into melt down which produces 35,000 degree > temperatures and blows plasma of vaporized copper out the front of the > enclosure. Having been near one I can tell you the sound is > like holding a 12 ga. shot gun next to your ear.</DIV> > <DIV> </DIV> > <DIV>Starting in 2004 the NEC started requiring arc flash studies and > labeling on all electrical panels in all non-residential facilities. > Most likely if you run into one of these panels there will be a label on > the door saying "the arch flash safe distance rating of this panel is 6 > feet" and indicate that arc flash protective clothing must > used before touching this panel. Any commercial > building owner who does not comply with these new regulations > can face criminal prosecution if somebody gets fried. The > safe way to approach any circuit breaker panel is to stand to the hinge > side of the door as you open it, and not stand directly in front as most > people do. This will deflect the high temperature plasma away from > your face if it happens.</DIV> > <DIV> </DIV> > <DIV>Here are several short YouTube videos, one of a security camera > view of two licensed electricians doing normal maintenance on new > switchgear. One guy is standing in front of a new large circuit > breaker that he is "cranking" into position. Later analysis > indicated one of the rear pins was bent, and as he cranked he was > deforming it sideways towards the ground buss. This new breaker > was not connected to any load. Let me say that again, there was no > load and no current passing through this circuit breaker. </DIV> > <DIV> </DIV> > <DIV>Since an arc has resistance, it allows enough amps > to maintain the arc, but not enough amps to trip the breakers, which > is why this will continue to burn and not trip anything. Also, this > may cascade back through multiple sub-panels as their can be enough > impedance in a long cable between a main and sub panel to hold down > the amps below the trip rating of the next breaker up the line. > </DIV> > <DIV> </DIV> > <DIV>Regardless of what you hear, this is not just a high voltage issue, > and definitely is a concern down to 208 volts AC which puts > it into the normal range of a residential 120/240 VAC main > panel. If you are adding or removing a breaker in an > existing panel to connect a new inverter, please make sure the panel > is de-energized and wear approved arc flash gear!</DIV> > <DIV> </DIV> > <DIV>Jeff Yago, DTI Solar</DIV> > <DIV> </DIV> > <DIV> <A > href="http://www.youtube.com/watch?v=m3_ear4k-Jg";>http://www.youtube.com/watch?v=m3_ear4k-Jg</A></DIV> > <DIV> </DIV> > <DIV> <A > href="http://www.youtube.com/watch?v=-iClXrd50Z8&feature=related";>http://www.youtube.com/watch?v=-iClXrd50Z8&feature=related</A> </DIV> > <DIV> </DIV> > <DIV> <A > href="http://www.youtube.com/watch?v=AFlBLQjOAJI&feature=related";>http://www.youtube.com/watch?v=AFlBLQjOAJI&feature=related</A></DIV> > <DIV> > </DIV><BR> <BR><HR>Netscape. Just the Net You Need.</DIV> > _______________________________________________ > 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
