Sorry to hear about that tragedy William. As a volunteer firefighter, (and of course a huge proponent of solar safety), I'm 100% supportive of, and encourage the use of "rapid" shut-down right at the module.
Eric Stikes Founding Director, GoodSun Solar A 501(C)(3) CA. Non-profit Corp. 001.530.798.3738 (cell) www.GoodSun.life [sent via pigeon...or cell phone] > On Sep 6, 2015, at 11:35 AM, jay peltz <jay.pe...@gmail.com> wrote: > > Dear William, > > I like all of your ideas, but they have one thing in common, they are all > passive. All the placards/labels/signs in the world won't prevent someone > from not reading or acting or miss understanding them. So I totally agree > with the NEC that we need automatic disconnects that prevent such events in > the future. > > I think this kind of sad event is the reason for the NEC to require > array/string level disconnect. > From what I've heard and I'm sure others are well more versed than I, but we > will see module level shutdown required in 2017 NEC, and I for one welcome > that. > > jay > > peltz power > sent: 11.35am 9/6/15 > > > > > >> On Fri, Sep 4, 2015 at 2:21 PM, William Miller <will...@millersolar.com> >> wrote: >> Dear Friends: >> >> >> >> Last week a local well technician was electrocuted. I had just met him in >> conjunction with a job we are about to do and realized right away he was a >> very nice person. He left behind a wife and two teenagers. Most tragic, >> his wife was working with him when it happened. >> >> >> >> The scenario is still not fully understood but here is what we do know: >> >> >> >> 1. The fellow was digging with a mini-excavator. >> >> 2. He knew buried lines were present and had turned off all circuits he >> thought were included. >> >> 3. He struck a power feeder. We don’t know if it was direct bury or in a >> conduit or if it was AC or DC. >> >> 4. Based on his impression the conductors were all dead, he jumped into >> the ditch with uninsulated dikes to cut the wire. >> >> 5. He had one hand on a t-post and the other on his pliers. >> >> 6. His wife grabbed his clothing but could not get him to release his >> grip. >> >> 7. An AT&T tech was nearby and donned hot gloves to pull him off the >> circuit. It was too late. >> >> >> >> This is an important issue for all of us. We work with high voltage >> regularly. We need to think about how to avoid this. >> >> >> >> I have connected with high voltage AC many times. My body always reacts to >> retract from contact. I got across high voltage DC once. I could not let >> go. I had to will myself to throw my arms down to break contact. The >> experience was frightening. >> >> >> >> On our crew we are integrating what we hope will be reflexive responses to >> given procedures. >> >> >> >> One is this: Every time you turn off a breaker to work on a circuit, the >> next thing you touch is a meter to check that the circuit is de-energized. >> >> Two: Don’t trust your inductive tester. It will not detect DC. It will >> not always indicated voltage present. >> >> >> >> This accident was at a local winery. Many wineries in this region have >> ground-mounted PV systems, many remote from the main service, therefore they >> have underground feeders. Most are string configured systems meaning the >> feeders are high voltage. >> >> >> >> It occurs to me that the uninformed worker might assume that turning off all >> the circuit breakers at the meter will de-energize a circuit, should it be >> compromised. Turning of the AC breakers would not de-energize a DC PV >> feeder. This is a problem. >> >> >> >> I spoke with another well technician about this . He was not aware of the >> safety issues associated with PV feeders. >> >> >> >> What to do? Here are a few suggestions: >> >> >> >> 1. Mark all conduits with bury tape 12” above the conduit. This does >> require extra work, you have to make two runs backfilling. >> >> 2. Sign the meter panel with an indication that opening all the circuit >> breakers will not de-energize all circuits on the property >> >> 3. Include your contact number so you can easily be contacted to >> reinforce the steps needed to be taken to excavate safely. >> >> 4. Always include disconnecting means at a ground-mount array. >> >> >> >> This issue is specific to excavation operations, but this reminds me of why >> I am so picky about wire shielding on ground mount arrays. This tragedy >> could easily happen to a child climbing on a ground-mount rack. >> >> >> >> Please add your thoughts on how to best manage the safety issues presented. >> >> >> >> William >> >> >> >> <image003.jpg> >> Lic 773985 >> millersolar.com >> 805-438-5600 >> >> >> >> >> _______________________________________________ >> 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 > > > > -- > Jay Peltz > Peltz Power > jay.pe...@gmail.com > _______________________________________________ > 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 >
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