I agree with Augusts' point. We use Delta LA's because some manufacturers (OutBack and Trace) recommended using them years ago. So, sort of the same reasoning Jay was saying about insurance.
Unscientific evidence from 22 years of experience with off grid systems in a fairly high lightning prone area suggests the following. Systems installed poorly (little care given to good grounding), by do-it-yourselfers mainly, have had a much higher incidence (with or w/out Delta's in the system) of inverter and charge controller failure than systems where myself, and or my crew, installed the system with good grounding techniques. We have had a very low rate of lightning damage with our own installs over the years. Both with the grid-tied, or off-grid, equipment. What Ray Walters said was the truth. Resistance to ground should be very low. How many dollars is that tester you use Ray? We don't own one. On the wish list. We get the ground Rods in wet earth, bond to our Sched 40/80 steel pipe masts that are encased in concrete when using TPM's. Bond to drilled well casings (in addition to typical grounding) when practical. When in doubt, get more copper in the earth. I learned from a lightning pro who is tasked with protecting police/firefighter/public safety communication towers here in hilly Vermont. Towers up high, on sites with shallow soils. Challenging situations for sure. They bring in graphite and pore that into deep holes they drill into the bedrock and then fasten their ground rods in these holes. The tower is surrounded with several of these ground points which are bonded together. There are other devices that are used on the tower to get static charges to ground that I won't get into. This lightning protection guy was chuckling at my use of the Delta cans and, with my permission, cut one open for inspection to educate me on the lack of substance to the design. He did not think that they would be very effective 99% of the time. But again we use them because there is not much else out there that is much better, for less than big dollars. Robin Gudgel (MidNite) has said that they will have a product, but I'm still waiting on my "Classic" beta units also. Has anyone got an opinion on the OutBack surge suppressor? Here is a company that says they have a product in UL now. Matt has been in touch with me over the past couple of years with questions on our PV systems. So, maybe this will be something. << Hi Dave, I just wanted to keep in touch and let you know that our SPDEE DC Electrical Surge Protector is currently being evaluated at this time for UL 1741 Certification. The approximate finish date currently is late November 2010. The demand for a UL 1741 Electrical Surge Protector from the Solar PV Industry prompted our company to move forward with this process. Matt Smith APT Industrial & Specialty Sales (800) 237-4567 (727) 535-6339 x 232 Fax (727) 539-8955 [email protected] >> David Palumbo Independent Power LLC Offices in Lamoille and the Champlain Valley, Vermont 802.888.7194 www.independentpowerllc.com NABCEP Certified Solar PV InstallerT Vermont RE Incentive Program Partner From: [email protected] [mailto:[email protected]] On Behalf Of August Goers Sent: Tuesday, September 14, 2010 9:01 PM To: RE-wrenches Subject: Re: [RE-wrenches] Delta LAs Jay - I can see that point, but does that really effect insurance payout? It seems like one could argue that a properly installed system with proper grounding inspected by a building official has a lot more clout than and little grey cylinder next to the inverter or disconnect. Please all wrenches, correct me if I'm wrong but I can't remember a single time when there was a post about an actual lightning strike and a lightning arrestor actually doing its job - meaning that an arrestor took a hit and protected the array and or inverter. I've heard plenty of stories about blown lightning arrestors and good equipment but no one seems to know what caused the situation. It might be that lightning is hard to track and I agree with that. And lightning might have been the cause. It would be great to track lightning-fried installations to see what happened and what could be fixed. If lightning arrestors are the solution then by all means we should install them. Most of the time I think that proper grounding is the solution although I wish that field experience would prove the point. What do you think? -A On Tue, Sep 14, 2010 at 5:28 PM, jay peltz <[email protected]> wrote: I also live in a area without much lightning, however I install one in most systems for the simple reason of insurance. If there is lightning damage, the insurance company can't use that as a way to not pay any claims. ie cheap insurance. jay peltz power On Sep 14, 2010, at 8:39 AM, August Goers wrote: > All - > > I guess my thought is a little off topic, but are lightning arrestors even worth using at all? My logic has always been that if lightning does indeed strike that it's likely going to blow the arrestor and and inverter. We don't have much of a lightning issue issue in the Bay Area so I don't have any direct experience. > > Best, > > August >
_______________________________________________ List sponsored by Home Power magazine List Address: [email protected] 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
