diy solar

diy solar

Boss Lady says learn on the PowMr 3k inverter/charger + 8 100w panels or it's COAL in my stocking

That is a handy thing to have , years ago I would touch them to see if they are hot .
I hammer punch my lugs, up to 4/0.
Twist cable, slide in , beat it with a mini sledge as if it assaulted your daughter in the night, then flood with electric solder warming with propane torch, then heat shrink. I sold my fancy hex hydraulic crimper yers ago. Side by side torture tests showed the hammered and soldered won hands down. Ice cold at max amps. Hex crimp got hot enough to discolor. Others have a diff opinion, I have a literal zero fail rate in decades of those though, used in terrible conditions with moisture and chemicals At max amps their whole life. It’s fun to side by side at full load and compare voltage drop after an hour, the hot one has an unacceptable drop, thats the die and dry crimp.

there are many different experiences you will find around here.
 
It's fun to point it into the fireplace insert and see where the hot spots are, then to the sky to see how cold it is up there.

That's not "cold", it's "light years" ;)

3000W/24V * 1.25 = 183A breaker

A few fuses might be cheaper than a quality breaker.

3000W / 22V / 90% efficient x 1.12 ripple factor x 1.25 to avoid nuisance trips = 212A

I hope the 183A fuses you blow are cheap.


Blue sea 200A breaker:


"Interrupt capacity: 3000A @ 24V"

How about showing him a quality breaker?

Better keep your fire extinguisher handy.
I'd rather buy two of those $45 fuses (plus more for fuse holder) than that breaker. It'll maintain good terms with the boss lady, too.
I assume 20kA from a lithium battery, but if you have internal resistance figures for yours you can calculate a better number.
 
I hammer punch my lugs, up to 4/0.
Twist cable, slide in , beat it with a mini sledge as if it assaulted your daughter in the night, then flood with electric solder warming with propane torch, then heat shrink. I sold my fancy hex hydraulic crimper yers ago. Side by side torture tests showed the hammered and soldered won hands down. Ice cold at max amps. Hex crimp got hot enough to discolor. Others have a diff opinion, I have a literal zero fail rate in decades of those though, used in terrible conditions with moisture and chemicals At max amps their whole life. It’s fun to side by side at full load and compare voltage drop after an hour, the hot one has an unacceptable drop, thats the die and dry crimp.

there are many different experiences you will find around here.
Ok, thanks Frick,

I have a mini sledge, a nice soldering torch - propane & Mapp gas, electrical solder, acid and flux. Probably won't treat the wire with acid but will clean the lug. Then flux lug & wire sparingly. I really don't want any residual flux hanging on to the wire though.
Thoughts?

Between the torture testing and checking temperature, with the laser thermometer, I should know whether I have a good connection or not.

So you hammer punch lugs "up to 4/0".
Does that mean you do or do not use this technique on 6 awg? If so, I'm good. I don't plan to get into the aught range, yet.
 

I'm not sure that Master Switch will work when I upgrade to 48 volts of battery with a real charge controller and nice inverter.
Continuous rating: 350A, Maximum voltage: 48V DC What happens when it exceeds 48 volts during charging?

Azamon recommends this for $15: ( i don't know what to say except NOPE! ) (n)
Kohree Battery Disconnect Switch, 12V-48V Battery Isolator Power Cut Off Master Switch Waterproof for RV, ATV, Car, Marine, Boat, AUTO, with 4 Mounting Bolts, 275 Amps, (On/Off)

Customer Reviews, (he gave it one star)
Melted
By Ted on May 17, 2021 I ran about 100 amps for 3 to 4 hours per day for a couple of months. After that time the product melted. At the time of the malfunction there were 14 volts going in and 11 volts coming out and I could not turn it off.

Back to the books for me.
 
Such things would melt if cables stacked on top of nuts or washers that aren't copper. Some designs are built that way.
A switch for this sort of current needs to have cable lugs pressed against copper switch parts.
Lots of them would be for intermittent use, like starter battery on a car, few hundred amps for seconds, 30 amps most of the time.

48VDC is a magical number in regulations. My current job for overseas industrial applications uses 60VDC as the magical number.
Above that voltage, greater effort is required to keep people from touching it. The actual safe/unsafe threshold varies with how sweaty your hands are and whether your feet are submerged in a wet bilge or are on wet ground.

Buy good stuff. And test for heat under sustained load (or measure voltage drop for faster indication.)
 
All my breakers are rated above 48 volts
I charge at 59.5 this time of year
And the temp compensation is 62 63 volts
If it’s cold enough ?
 
That's not "cold", it's "light years" ;)
I just checked and my Laser doohicky can see -34 up in tonights sky. Is that years, hundreds, thousands, millions or what?
FYI it's an old Raytek, Raynger SD.
FYI it's an old Raytek, Raynger ST.

Not that I would ever do this BUT one could use it to make a cat run right into a wall. :oops:
 
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I just checked and my Laser doohicky can see -34 up in tonights sky. Is that years, hundreds, thousands, millions or what?
FYI it's an old Raytek, Raynger SD.
Not that I would ever do this BUT one could use it to make a cat run right into a wall. :oops:

Well, considering someone proved the moon landing was faked by the reasoning that a region of space which is 2000 degrees would have melted the spaceship, I assume your laser was of a wavelength which didn't interact with those molecules. You got -34 degrees (not "42"?), not sure why, but I do know it is still traveling, maybe hasn't even passed Saturn yet, and global warming will have made the Earth uninhabitable long before the signal from the stars ever returns, so you won't get to see the reading.
 
Ok, thanks Frick,

I have a mini sledge, a nice soldering torch - propane & Mapp gas, electrical solder, acid and flux. Probably won't treat the wire with acid but will clean the lug. Then flux lug & wire sparingly. I really don't want any residual flux hanging on to the wire though.
Thoughts?

Between the torture testing and checking temperature, with the laser thermometer, I should know whether I have a good connection or not.

So you hammer punch lugs "up to 4/0".
Does that mean you do or do not use this technique on 6 awg? If so, I'm good. I don't plan to get into the aught range, yet.
6 ga is easy,though kind of wimpy. What is the expected load though it at what length?
 
6 ga is easy,though kind of wimpy. What is the expected load though it at what length?
I agree, thanks.

The plan is to run 4 awg THHN, 55' to the charge controller.
Panel to combiner box = max 20', so I plan to use 10 awg solar wire tying everything together.

With 8 panels, 4 series, 2 strings = 67.08 vdc, 12.52 Amps from combiner to charge controller (55') = 8 awg THHN, loss = 2%.

When I add 4 panels to the current 8 panels, the array will be: 3 panels series, 4 strings to combiner box.
12 panels at 50.31 vdc, 25.04 Amps from combiner box to charge controller (55') = 4 awg THHN wire to keep loss @ 2%.

I would like to run higher voltage but the charge controller is limited to 100 vdc input so I can't put 4 series & 3 strings.
The resulting VOC @ -40 F° is 96.4 vdc. I think that's too close for comfort.


8 panels arrived today.
The numbers vary slightly from those at Newpowa dot com.

Newpowa Model: NPA 100S-12H
100 watts
VMP 19.83
VMP 16.77
ISC 6.56
IMP 6.26
 
Alrighty, the panels arrived.
Time for me to get my butt in gear.

I know most folks think the little panels are silly but I'm old and can't haul the same shite I could awhile ago. Neither can she.
The panels are (everything from here on out is "approximately") 44 x 20 inches, 15 pounds.

The boss lady said "no way are we moving a sheet of plywood & 4 panels".
So in my infinite wisdom I heard her say "mount 2 panels on a half sheet of 1/2" plywood" and try to keep that from blowing away.

I'm damned determined to be able to orient them throughout the day. It's not like I'm gonna be watching the grass grow during the winter, so I may as well tweak the panels towards the sun.
For those of you thinking I'm nuts, just wait till your old and got nuttin else to do.

FYI: There's hundreds of miles of leftover oil field pipe available all over the place around here. But no, I will not stick these panels way up in the air.

So, a single post with 3 anchor points, one each for morning, noon, and afternoon will make me happy, till I figure out how that does not work.

Wy Not play with adjusting the panels throughout the day? I think I can double or even triple my (crap, I don't know what it's called) power throughout the day.

I've cleaned my ears and am open to suggestions. I love the idea of overpaneling but right now I have 8 panels and I need to show the boss lady how productive they can be without starting a fire.

Next up: SNOW REMOVAL, oh joy!

Tomorrow, Monday, the Charge Controller/Inverter arrives.
Thank goodness the Combiner Box won't be here till next year.
 
Alrighty, the panels arrived.
Time for me to get my butt in gear.

I know most folks think the little panels are silly but I'm old and can't haul the same shite I could awhile ago. Neither can she.
The panels are (everything from here on out is "approximately") 44 x 20 inches, 15 pounds.

These are simply additional design considerations, and they're as valid as any. While likely not as old as you, I'm good and fat, and lugging 50# panels is not on my list of fun things.... having done it a crap-ton.

No judgement here.

The boss lady said "no way are we moving a sheet of plywood & 4 panels".
So in my infinite wisdom I heard her say "mount 2 panels on a half sheet of 1/2" plywood" and try to keep that from blowing away.

I'm damned determined to be able to orient them throughout the day. It's not like I'm gonna be watching the grass grow during the winter, so I may as well tweak the panels towards the sun.
For those of you thinking I'm nuts, just wait till your old and got nuttin else to do.

That can be diminishing returns, BUT, a simple single post with tilted panels that rotates at the base is a reasonably decent low-effort tracker. Depending on our latitude, perfect 2 axis tracking will get you an average of about +40% over fixed year-round panels

You can simulate it for your location with PVWatts. :)

FYI: There's hundreds of miles of leftover oil field pipe available all over the place around here. But no, I will not stick these panels way up in the air.

So, a single post with 3 anchor points, one each for morning, noon, and afternoon will make me happy, till I figure out how that does not work.

Wy Not play with adjusting the panels throughout the day? I think I can double or even triple my (crap, I don't know what it's called) power throughout the day.

Nope. See above.

It's not just about positioning but about the intensity of the solar radiation. The only time you'll get 1000W/m^2 is at high noon and perfect conditions. It's at a minimum at sunrise/sunset, and it increases/decreases progressively as you approach/leave noon.
 
For those who don't want to be at the beck and call of the moving sun, I would suggest seasonal tilt.
Over-panel by having two (or more) PV strings split between two arrays, one oriented South East and the other South West. They can total about 1.5x what SCC is rated for, because with 90 degree angle between them the area presented to sun is 0.7x as much.
Two or four times a year, they can be tilted for the season. Although, I have read that on overcast days the optimal angle is straight up at the clouds.


My 327W SunPower panels are a handful. Those I've only placed on head-height groundmount panels. Smaller panels I've climbed a ladder with and lifted overhead to place on rails. 4x8 sheets are even more difficult. There are gadgets to hook under lower edge, and I used a binder strap over my shoulder last time I had to move a couple. I don't enjoy it.

That 3" steel pipe would be great for a large ground mount. I used 2" threaded pipe or conduit. If they are cheap, just weld flat plates on straight or angled cuts and use U-bolts to clamp on other pipes. Or, angle iron welded to flat plates as a cradle to U-bolt on ends as well.

That can be diminishing returns, BUT, a simple single post with tilted panels that rotates at the base is a reasonably decent low-effort tracker. Depending on our latitude, perfect 2 axis tracking will get you an average of about +40% over fixed year-round panels

You can simulate it for your location with PVWatts. :)

In winter, there is less swept angle of the sun to track.
In summer (which could matter more for people who's main load is A/C), more swept angle so more power available.
 
You can simulate it for your location with PVWatts. :)
PVWatts is a nice site. My (optimistic) number = 7% loss

Latitude 44 North, Elevation 4500 feet, Sun Angle Today 23. Sun angle at Summer solstice 70.
Typically we have clear blue skies. Of course today is as grey as they come. We do get wildfire smoke degrading the light much of the summer.

Sounds like I'm hearing "There is no 2 for 1" and the best I could do is maybe 1.5 times a single fixed array.
For those who don't want to be at the beck and call of the moving sun, I would suggest seasonal tilt.
Over-panel by having two (or more) PV strings split between two arrays, one oriented South East and the other South West. They can total about 1.5x what SCC is rated for, because with 90 degree angle between them the area presented to sun is 0.7x as much.
Two or four times a year, they can be tilted for the season.

I'm liking the idea of Over-paneling with two arrays.

Thanks for pulling on the reins. Sometimes I go a bit overboard.
 
Charge Controller arrived yesterday, Combiner box showed up today, wire shipped yesterday.

Getting things figured out, maybe.
 

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The 63a breaker from the panels, future proofing or what came in the box?
Cool, Thanks for checking.

The 63a breaker is another level of safety AND a disconnect in the equipment area. Boss lady wants an easy to use disconnect. I listen well.;)

#3 Placing a 150a fuse between battery shutoff & batteries sounds good to me.
Could that be a breaker and still achieve the same level of protection? Still doing research, but seems like fuse/breaker is the same.

Edit: I have 2 MidNite, 150 vdc, 20 Amp circuit breakers for use in the combiner box.
The combiner box is the last exterior component of the system.
 

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