PLEASE NOTE: If you had an account with the previous forum, it has been ported to the new Genetry website!
You will need to reset the password to access the new forum. Click Log In → Forgot Password → enter your username or forum email address → click Email Reset Link.
So as you know we are building a 30KW off grid array here at the homestead and while in the build phase I am looking at all of the equipment I will need to put this project together. But there is one thing that I have wondered about and I am looking for some honest feedback.
That is do I really need Lightning Arrestors? Now I know that having something weather you use it or not is good insurance but you also pay for said insurance and when protecting a 30kw array the cost can add up rather fast considering that each arrestor (a good one) can approach 100 bucks each. Now I will absolutely ground the equipment with several ground rods but I am a bit cynical towards GFCI and Lightning Arrestors.
Perhaps there is a system wide arrestor I can use instead of mounting one per combiner box? Do you think these things really work? Is there a good study that can prove or disprove that they work as intended?
Code is starting to get more and more strict even with isolated off grid installations and while not everyone follows the rules I do want the system to be as safe and reliable as possible.
Chime in with your thoughts
Personaly, I think its a waist, if the combiner box is inside or even on a wooden post with a normal ground wire should be enough.
At the moment my solar array isn't even ground for the past two years, and I've not had any problem, and I have a 20 ft pole sticking above it with a weather station on the backside of the array, which would seem to be more a lighting magnet, and now a wind turbine on the other side of the array.
Just my thoughts, I might end up grounding it anyhow this round once I get my GS inverts, since I'm going to put up another big array. I'm hopeing to get up to 10kh level by the end of the year.
So as you know we are building a 30KW off grid array here at the homestead and while in the build phase I am looking at all of the equipment I will need to put this project together. But there is one thing that I have wondered about and I am looking for some honest feedback.
All depends on how much chance of lightening you have in your area and whether it would be protected from a strike by surrounding tree/towers/buildings. I live in a high strike prone area. Our house has had two direct hits on it in 43 years. The first strike blew some gutter spikes out and melted part of the guttering before jumping over to the Italian Cypress.The trees showed where it had gone down them to the roots. A computer monitor inside ended up with a pink screen because of the EMP. It wasn't plugged in at the time even. Degaussed it and all was fine. Second strike came in just below the soffit blowing out a chunk of plaster. It then followed a conduit in the attic till it found a weak spot in the wire going to the stove. It fused the one leg of the 240 line to the conduit. It then followed that wire to the breaker and also the conduit to ground. A house about two miles from us burned to the ground from a strike. Reason we get hit is we are in a two story house out in the open. We now have some tall Palm Trees which will divert the potential away from the house. At work, every thing was grounded as we had radio towers.
In Ohio, the farm house and the barns have lightening rods. The other houses we have there do not. With what you are going to install, I would put in some spark gaps at least on the wiring to discharge it to ground besides and apart from grounding the frames. Or have Sid design you a unit to capture that Voltage to charge your batteries. If you look at some of the free energy sources there are units that can capture electrostatic energy from the air. And all of them have to have spark gaps to kill off the possibility of a strike on the system. This recommends using an auto spark plug for one although I'd go with a D-16 plug for its beefiness. http://www.free-energy-info.com/SChapter10.pdf
Interesting indeed. I do not know if we are at high risk. Do you know of any products in particular that can help mitigate the risk of a strike?
The Intermatic ones will work for one strike. Which really is about all that most will work for. AT&T uses carbons to stop lightning surges but again, after one strike, they need adjusted or replaced. Or you can do it cheaply and use MOVs. For a 240V split phase line you would use 3 rated at about 260V. One each from line to neutral which is grounded and on from line to line. Depending on your array Voltage, you want ones that also are just above the maximum Voltage you will see on the panels. They are cheap protection for your equipment.