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

WYtreasure

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If your grid input is really a 50A breaker, I'd recheck that wire. IIRC, that should be 8 or even 6 for 50A.
Another good call on your part TorC. The grid power 50A, single pole breaker is to accommodate future growth. This drawing is corrected for both circuit breaker amperage and wire size.

My DIY assembly instructions remind me to use 6 awg from AC Main to disconnect, but I must use 8 awg from disconnect to controller AC IN due to wire size limitations on the controller.
Here are 2 excerpts from my DIY manual.
1) "AC Main Panel OUT to AC Disconnect IN - Southwire, Romex NM-B, 6/2 with Ground; Quantity 1, Length 25 23', Black, 6 AWG, Stranded, 90°C, 55 Amp Rated. Circuit Breaker Torque 45 In/Lb."
2) "AC Disconnect OUT to Controller AC IN - WindyNation, CBL-CSBL/RD-08, 8 awg, red and black; Quantity 3 (one wire taped green), Length 2', Black, black (taped white), black (taped green), Stranded, 125°C, 55 Amp Rated. Circuit Breaker Torque 40 In/Lb."

If your inverter can pass the whole of that through, then you should must use at least the same wire for the inverter output.

My AIO controller Max bypass input current is limited to 40 Amps. I believe we are both referring to the same same values.

Wire and fuse sizes FIXED in drawing 499. (y)
Plan 499.png
 
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TorC

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Quick look says that looks good on wire sizes. Even if it's marginal for the standard ampacity, a very short run with good free air around it won't risk heating, which is the primary area of safety concern.

One serious problem: your 60A fused battery disconnect. 3kW/24V=125A. It'll blow long before you finish loading your inverter. Also, your 150A Class-T fuse could probably be increased. It's purpose is only to interrupt a dead short. I'd think about a 200A to match a 1C safe discharge rate.
 

WYtreasure

It's not happy hour, I'm just like this.
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According to your numbers, going to a 4S3P panel arrangement will be 19.5A, which is within the standard ampacity of 12ga. 55' isn't that long.
My drawing does not reflect the unusual setup in the combiner box. It really is 4S 2P. I have inverted the third breaker as another line of protection.
That said, finding identical panels when it comes time to upgrade isn't always easy.
These little panels have been on the market a couple years, hopefully they will be for another year. We have a few locations where this system can be relocated without expansion if I cannot find the same panel in the future. I'm not a fan of mixing panels with different specs.(y)

For that reason, I'd still consider running a second wire for your new panels, either at time of expansion or now if you're definitely planning to expand and/or it's very hard to add a second wire. If it makes sense, you can combine old and new at the SCC instead of the roof. If you install two wires you can run your current strings back to SCC separately and combine there for lower line loss.
Sounds pretty good. Conduit is a straight shot, literally and I have a habit of leaving a pull string in conduit. I think it's about time for me to try those fancy new "Push-To-Connect" fittings.
Outofthebox BoX.PNG
All great stuff.
 

TorC

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You mentioned increasing the size, so I was running some numbers on my interpretation of the future potential plan. I thought I read something about half again the system, so I was looking at limits after considering adding another four panels.

Mixing panels of different specs is a mixed bag. Pick good matches and losses are trivial. Bad matches arent. If you're using a good chunk of your SCC capacity, adding a second SCC for the mismatched panels obviates any need to worry about matching, except perhaps as it relates to makeshift combining while replacing a failed SCC.

A straight shot conduit makes it easy. Sounds like you know all about what happens when you don't consider future expansion.
 

WYtreasure

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A straight shot conduit makes it easy. Sounds like you know all about what happens when you don't consider future expansion.
Yep, been there done that. It sucks.
One serious problem: your 60A fused battery disconnect. 3kW/24V=125A. It'll blow long before you finish loading your inverter. Also, your 150A Class-T fuse could probably be increased. It's purpose is only to interrupt a dead short. I'd think about a 200A to match a 1C safe discharge rate.
I'm still scratching my head on this one. I have intended to derate the inverter, voluntarily, to about 2k for the current build. That won't even be enough. I had a plan a while back but it never made it to paper, so it's gone from me knoggin.

I attempted to design the system to accept a total of 16 100 watt panels, of the same specifications. So the numbers just double on Amps in. It's a bit much for just the 2 batteries but with proper management of loads I think it will work out well.
The All-in-one will be relocated to a smaller house or to the greenhouse if we expand beyond 1600 watts of solar panels.
 
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TorC

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Fuses are to protect the wires. Secondarily a device in some cases. Size the wires and the fuse for the maximum load. If your batteries really couldn't handle a fully loaded inverter you could put in a circuit breaker at the battery limit, but I'd prefer to just not put to much load on the output. A fuse in that case, however, would get expensive. Nor do you need to. 200Ah LFP are OK with a 1C, or 200A discharge, and a brief overcurrent startup surge isn't a big deal. Your maximum potential continuous load on the battery at 85% inverter efficiency is 147A.

1600W panels converted to 24V is 67A. Well within the 100A .5C normal LFP charge allowance.

The inverter will never draw more than the load on it plus the inefficiency of the inverter itself. Load it lightly and your battery will never see that worst case drain, except perhaps approaching it very briefly when you start a vacuum or something. No big deal.
 

WYtreasure

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Fuses are to protect the wires. Secondarily a device in some cases. Size the wires and the fuse for the maximum load. If your batteries really couldn't handle a fully loaded inverter you could put in a circuit breaker at the battery limit, but I'd prefer to just not put to much load on the output. A fuse in that case, however, would get expensive. Nor do you need to. 200Ah LFP are OK with a 1C, or 200A discharge, and a brief overcurrent startup surge isn't a big deal. Your maximum potential continuous load on the battery at 85% inverter efficiency is 147A.

1600W panels converted to 24V is 67A. Well within the 100A .5C normal LFP charge allowance.

The inverter will never draw more than the load on it plus the inefficiency of the inverter itself. Load it lightly and your battery will never see that worst case drain, except perhaps approaching it very briefly when you start a vacuum or something. No big deal.
Yep, that all sounds good. Fuse for the wires and devices after that.

The AIO unit is inexpensive and I have no intention of testing it's limits. Solar input is limited to 1400 watts, but allows for overpaneling up to 1600 watts. We get a great deal of pure sunshine at 5,000 feet so I will probably go with 4 panels slightly east, 8 panels at south and 4 panels slightly west. Nothing will be permanent so I can experiment.
We do well managing loads most of the time and can manage even better when we have to. With a dedicated main panel supplying loads to fridge, freezer, lighting and essentials, the inverter & batteries are expected to run at <40% capacity when I have fine tuned the system.
I still have to figure out that battery discharge issue, no matter how many fuses I keep on hand.
 

LittleLebowski

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No plans for wind power? I’m a WY native and I’m planning to move back to Best State soon, I’ve been trying to learn more about wind power in top of solar. Please ignore if I am rudely off topic.
 

WYtreasure

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No plans for wind power? I’m a WY native and I’m planning to move back to Best State soon, I’ve been trying to learn more about wind power in top of solar. Please ignore if I am rudely off topic.
Snot rude in my book. :LOL:
Welcome to the party LL.

I started thinking about wind power 15 years ago. A buddy of mine said it would never work. A couple months later a big local electrical company was hooking up his used 20 or 30K windmill. This is coal & oil country so wind & solar doesn't always go over well, more-so back then. Anyway, there was magic smoke.
The electronics were done over and this time the house almost burned down. The End of alternative power for him.
Recently I considered wind to accompany solar.

You probably know that if it's really crappy weather, no solar, dead of winter, cold as all getout, the wind is blowing to beat hell. So one would think, as I have, that's a lot of energy blowing by. I have spoken to a couple US wind turbine manufactures, and they are not very optimistic about the outcome. Tonight is a good reason why. Funny you would ask the question today.

Here's tonight's forecast, for Gillette, close enough for what we're chatting about.
Breezy to 75 mph April 5 2022.PNG


That was the long answer. Short answer, I'm still thinking about it.
I won't be calling a local electrical company to do solar or wind. My experience is that solar & wind are only popular and accepted if you're not near the grid. I think that's funny considering some oilfield electricians are pretty experienced with solar. Things are changing though. (y)
 

LittleLebowski

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My family is an old Wyoming ranching family (the original family homestead from 1890 is still in the family) and both them and all of the ranchers I know are enthusiatic about any alternative power source that works. We switched a lot of our livestock wells from wind to solar, they work great.
 

73powerstroke

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Is the MNPV6 for future expansion?

4awg might be okay for the battery/inverter cable, but you're going to have a lot of voltage drop at peak. I'd go 2awg.
I have 2ga wire 5 feet long to my 2000w inverter. I should have went 00/2. But im also 12v. My wires get warm. And I get voltage drop. ⚡️ go bigger
 

WYtreasure

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Lot of good info in here , any updates?
Welcome to the party chevyman09.
Happy to here you got some good info from the thread. I enjoyed learning my way through it. I went from knowing nothing to KNOWING EVERYTHING... NOT. ;)

The Boss Lady changed my mind numerous times before the first "Solar System" was created. At this time I am gathering materials and info for our new Growatt SPF 6000T DVM-MPV.

I'm learning lots of new stuff "again" but nothing worth sharing.
 

Rednecktek

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The Boss Lady changed my mind numerous times before the first "Solar System" was created. At this time I am gathering materials and info for our new Growatt SPF 6000T DVM-MPV.
Looking forward to your posts in the Buy & Sell section. :)

In other news, just got told at least 17 more days of winter, nobody to relieve me. :(
 
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