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I thought the same thing with 12v at 160ah. Please tell us Larry how you do it without going below 50% SOC???

My welder is a Hobart Handler 120 mig. It draws 20 amps a/c at full power. My inverter is rated at 2800 watts or 23 amps a/c. So as you can see with only one inverter I was nearly maxed out, and if the wife was doing anything in the kitchen it would be over max and pop my 250amp DC circuit breaker on the inverter input. So I added the second inverter. Now I have 46 amp a/c capacity. The master inverter runs most everything in the house and garage but if the demand is great enough the master will wake up the slave inverter and it will add its power until the need drops and then it goes back to sleep. As far as state of charge on the batteries, I am not running a production shop. The welder might be on for a total of 15 to 20 minutes a day during a welding project. Lets say it draws 240 amps out of the batteries for 1/3 of an hour that figures out to 80 amp hours out of the battery bank. My solar panels will produce about 70 amps but only about 50amps actually go into the batteries because of other loads, so it should take about an hour and 36 minutes to replenish what I use in 20 minutes of welding. If I am already fairly low on battery power I can always start my generator and my 2 inverters will charge my batteries at a max of 250 amps an hour.
Larry
PS My AGM batteries are 96% efficient so the actual time to recharge them will be a little higher but not much, maybe an hour and 45 minutes, but who wants so to get that picky.

PSS Ron, My batteries are 1600 amp hour capacity, You typed 160, and I thought maybe that was just a typo. If that was my actual capacity then you would be right I would have a problem keeping them from discharging too much.

Yes, that was a typo - I meant 1600.

I actually expected that welding would draw more than 20 amps. Very cool...

While we're on the subject of solar....

I'm happy to report that the security hardware some of the solar companies provide works very well. I bought additional solar panels of the same brand that I already have. Unfortunately, they changed the location of the mounting holes. I can't put them on the same rack as the older panels. I had to remove a couple of panels to split the rack between new and old. It took me nearly half a day to get the security nuts off of two panels! Talk about frustrating! If I was a thief I think I'd have given up a looooong time ago.

We have a security system for protecting our solar panels (and everything else) too. It's called DKB.

Dakota - Kojo and now Beba who is almost full grown now!

Jeff
I am not familiar with the security hardware you are referring to, Could you tell me where you got it. I have always felt that my panels are at risk when I am back in San Diego and no one is around to watch them.
Larry

One way screws work great. They are a real pain to get out...

Originally Posted by rplarry

I am not familiar with the security hardware you are referring to, Could you tell me where you got it. I have always felt that my panels are at risk when I am back in San Diego and no one is around to watch them.
Larry

These are the ones I used on the panels I already have on the roof:

http://www.hudsonfasteners.com/sec/sec_sp_nut_rem.htm
http://www.hudsonfasteners.com/sec/sec_sp_thms.htm

The downside to the bolts above is that the tool to tighten the bolt is really weak. I kept breaking off the tabs that go into the holes. Believe me, they are a nightmare to get off though. I broke my last tool and finally wound up grinding them off. Took forever. The tool for the bolt is tougher and didn't break.

On my new panels I'm using these:

http://www.tufnutworks.com/category...._Security_Nuts

and these again:

http://www.hudsonfasteners.com/sec/sec_sp_thms.htm

If you are mounting on a concrete roof, for the feet you can use red-head fasteners, which have the threads protruding from the fastener, along with the toughnut to secure the feet.

These are what a lot of people use, http://store.solar-electric.com/mohasebo.html but I wondered if it would be tight enough when the nut broke off? What if it loosens up some?

I'm not as worried about the panels as I used to be when I left the house vacant. Now that we live here, it's not so much an issue, and If I go anywhere for any length of time I have someone stay at the house. But... why take a chance.

I would think the nuts are better.

If the bolts are not in a recessed/protected area, can't you just cut a slot on top with a hacksaw for a regular screwdriver?

My panels are mounted ToP (top of pole) on a solar tracker, so when I am gone they are easily accessable from the ground. So these security fasteners look pretty good to me. Obviously, given enough time someone could defeat them but anything I can do to make it more difficult is in my favor. Thanks for the links.
Larry

I have found that thieves down here can be extremely resourceful. They seem to find a simple workaround to whatever means you come up with to keep them from what they want to get. They will use cordless drills, saws and bolt cutters as well as many other tricks.

I thought about going to some extreme means to secure my panels but to be honest I have a lot more faith in my three dogs. Beba and Dakota especially get folks to stop at the property line and this summer we will be bringing down Kobe, Beba's older brother. He's a black doberman and even bigger.

A great dog but when he gives you "that look", people run...

It's not that expensive, and maybe it will cause enough frustration that they will move on. No one would be able to get the panels off quietly and I'm pretty sure power tools would wake me up since the panels are just outside my bedroom.

Another one of the reasons I hesitated in using them was thinking about what if I ever need to work on the system? It would be just as hard for me to remove them too.

I'll just get another couple of dogs...

Dogs are great, and I would probably wake up also if I heard someone grinding on some bolt heads. But when I am not there for months at a time, like now in the summer when it is just too hot for me to be there, I'll have to rely on making it harder to get my panels than to get my neighbors panels. My garage and house got broken into last summer, and I didn't like it. This last year I spent most of my time installing an alarm system and fabricating metal bars for the doors and windows. Again just trying to make it harder to get into my place than my neighbors. I know that "they" can get into anything given enough time, and resources.
Larry

I have met many folks who live down here part time and the best security solution for them that I have seen is to have somebody living on the property in their absence. A good friend of mine built a great place down in the El Rosario area and only spends about 25% of his time there currently. He recently built a small studio apartment and just found a couple to live there rent free in exchange for watching over his place.

A couple who have a place up the coast from mine who are part timers with the same problem did something similar. They brought down an old trailer a few years ago and hired a caretaker. He takes care of maintenance and landscaping and feeds the dog when they are gone. He gets to live in the trailer for free and they give him two hundred dollars a month. They tell me that they have not lost a single thing since he has been there. She loves the fact that he keeps all her gardens green and flowering and her husband no longer has to climb under the truck anymore for oil changes/brake jobs or fix leaky faucets. They all feel this is a great arrangement and they have developed a great bond with the guy who has become more and more like family.

They have poured the foundation to build him a small 1 BR place in lieu of the trailer and hope to have it finished before this winter.

I really like that kind of solution...

OK, as promised. My updated power diagram showing the system all 24v and including breakers, shunts and fuses. Please comment if you see I left anything out???

Oooo, FANCY diagram, BG! (She said, having no idea of what it means. )

Well if you are even considering living off grid you'd better learn fast!!!

You've come a long way!

Here's a few things that I've wrestled with trying to understand, or had to go back and install/change that aren't in your drawing:

--System ground at least 6 gauge wire tying all the chassis components together. Some say each panel should have a ground lug. I talked to an engineer that said that's overkill and grounding to the frame of the panel mount is fine.

--Neutral, ground, and system (safety ground) bonded at only one location, preferably the main breaker panel.

--Battery negative does not have to be bonded to neutral and system ground, but if you do, it cuts down on any radio interference the inverter may produce.

--Check to make sure neutral and ground are NOT bonded together in the generator.
--Do not run the system ground for the generator to a separate ground rod. This can create a ground loop that could overheat the windings in the generator.
--Generator system ground should be tied back to the main ground buss.

--Make sure you only have one point where the system is grounded to earth. I'm not sure if that's the right terminology, but you should NOT have separate multiple, earth ground points.

--If you can, locate the ground rod in a garden area that gets watered regularly ( I don't, I plan to move it). Dry desert earth doesn't conduct very well or make a good ground.

--I'm not sure if lightning is an issue where you are, but if it is, (even occasionally) you should have lightning protection in:

1. Combiner box
2. Something in the wind generator, but I don't know what as I'm not familiar with those, and I would imagine in the wind turbine rectifier
3. Charge controller
4. Inverter
5. Input from generator
6. Main AC panel and any sub panels

I've done all the above. Now I just hope it's correct

How's your system working out?? I bet you're glad you have the wind generator. I noticed my system charges fine with high clouds, however this spring, the low coastal clouds/fog really cut the output of the panels. I could have used the extra charging.

Super good/important points about grounds Wooo; they're the drain that all your filter capacitors use for noise.

Sure don't want those clogged/non-existent.