Author Topic: Layout of a new 800w system  (Read 1203 times)

UpNorthMan

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Re: Layout of a new 800w system
« Reply #30 on: January 20, 2018, 08:17:59 AM »
I have looked at other inverter /charger systems. The Victron Energy system also looked attractive. From what I've read, it doesn't meet the output requirements of 120 v 60hz. Some of the other higher rated ones fall short in the 48v range. I'm not trying to put any manufacturers products down. Manufacturers have a sweet spot or target user for their product. But reality is that I need a reliable system that can handle some extreme cold temperatures. This system is for a cabin, not a home so if there is a problem and I'm not able to address it. One of my contacts can just fire up a portable generator for a few hours to bring up the battery's SOC until I can address the malfunction. I live 3.5 hours away. I am planning on having some sort of monitoring system that can send basic system information. This is something that I will have to look at later. I only have cell service, so there is another set of parameters. I'll cross that bridge later also.

As far as temperature, the cabin is 25 miles NW of Tower MN. This is one of coldest spots in the state. We aren't located in the valley like they are, but it still gets darn cold.
http://www.fox21online.com/2017/02/02/coldest-place-small-minnesota-town-earned-states-frigid-title/

I looked at the crystal battery. It does at first glance look appealing. I'll do more research on it. I am looking at a 225ahr @48v system. I am truly looking for a battery bank that can be kept in the cabin. Safer, warmer, shorter cable runs. With fla, I would have to build a insulated battery box under the cabin. My cabin is built on piers, so there is room, just more to build and mouse/ squirrel proof.
 

Thanks Ed
« Last Edit: January 20, 2018, 07:04:29 PM by UpNorthMan »

CDN-VT

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Re: Layout of a new 800w system
« Reply #31 on: January 20, 2018, 09:52:00 PM »
Tower MN = https://en.wikipedia.org/wiki/Tower,_Minnesota


Nice size Town Ed.

Bury the cells is what i was going to post , You are on rock or dirt ?
You might need to make a special cell box that's insulated and built like the new Styrofoam blocks that you pour  cement into , offers insulation & then You can double the insulation with :https://www.lowes.com/pd/Insulfoam-Common-0-5-in-x-4-ft-x-8-ft-Actual-0-5-in-x-4-ft-x-8-ft-R1-9-Faced-Polystyrene-Garage-Door-Foam-Board-Insulation/3033278

Then vent from the bottom of the box   small amounts in winter.
You will need VERY large cables to feed the Outback  So I would plan on using two drops of PVC from the cabin into the Cell box & feed small air from cabin to the cell box through the PVC & have one for POS & Another for NEG  . I have used Aluminum wire that we use for grid tie  that feeds the house. That with industrial fittings to transfer large amps on startup to feed the inverter . We use nylock grease on the wire & terminals . This way the voltage drop should be very little.

Next on the inverter . I picked VFXR3648 in the case it needs  field work ,
I bough Robins older Outbacks that needed a slight repair , I called outback tech repair & got them the send a board , swapped it & sent the old one back .
The Tech lady I dealt with sent instructions & spare seals & hardware.
Field serviceability is WHY i picked  Outback , till Midnite  comes outwith  theirs..
VT
Canadian Solar 350W 37.6 VOC  30.6 VMP 8.22 ISC 7.87 IMP ,-15 c +30c max  4 strings in 2 in Series for 24v Classic 150 -1020 Ah  Freezers & fridges ~~~ Second Array same panels of 3sx3 parallel for 24 V Classic 150 -440 Ah Outback Barns & out blds.
48Vdc almost done.

UpNorthMan

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Re: Layout of a new 800w system
« Reply #32 on: January 24, 2018, 06:43:25 PM »
Tower and the surrounding  Arrow Head region has a lot to offer in the way of recreation and adventure. The Soudan mine is a neat place to go and visit. I've been there a couple times with the family, 1/2 mile pretty much straight down. They also perform some science experiments down there. All can be seen with a tour. The whole area has a lot of mining and lumber history along with other outdoor recreation.

I am lucky, there is dirt under the cabin. A lot of places in that area have a lot of rocks. You have to dig as big around or bigger  compared to depth. So many large heavy rocks.

Burying it does make some sense, It would help with some of the temperature extremes. There is some grade under the cabin, 5' drop in 32', I might be able to use this to my advantage. You mentioned venting out the bottom, are you thinking like a 2" PVC pipe from the bottom and then out the side and up? Then my cable drop('s) come in from the bottom/side. And use a small pancake fan to apply positive pressure into the drop pipe. I've read that the +- cables should twist, or at minimum, run parallel to each other and tape together. Would this be recommended?

Right now, there aren't any walls up inside, so a piece of 3" conduit wouldn't be an issue to install. I'm not sure on the exact size required, that will be determined when wire sizing is done. Do you know if the drop pipe has to be steel conduit for code. A friend mention it need to be steel, not PVC.

I can design the box cover area for more ventilation for summer. I was thinking of something along the lines of adding heavily screened in wall extensions that would lift the roof up enough to get past the insulation.

I appreciate the inverter suggestion and I believe I understand the reasoning behind it.
Do you know if there is a setting on the VFXR3648A to limit inverter output wattage. Either on the Dc input or AC output. Not the through circuit. Depending on the battery type at startup I may need something smaller. I'm hoping for Aquion Energy batteries. But I won't be able to afford all that is needed right away. Due to old output specs, at least 5 would be needed, probably more. I haven't done enough research and they still aren't available.

Ed

ClassicCrazy

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Re: Layout of a new 800w system
« Reply #33 on: January 25, 2018, 12:19:59 AM »
Twisting your cables if you can is good to cut down on RFI noise .
Last I heard Aquion went bankrupt but I just looked them up and see they came out of bankruptcy . When I looked at their battery specs a couple years ago - they were very large and heavy for the amount of energy they can provide. And I thought kind of expensive. Never did hear from anyone who has them how well they really perform in real world .

Do you have code up there you have to follow ? Or is it just best practice electrical installation you want to do ?  I don't really know all the ins and outs of code but I don't see what difference it would make using PVC conduit instead of metal - though I don't know where you ant to run this conduit.

As far as batteries staying cool - having space between them is good otherwise the inner cells will get warmer than the ones on perimeter.

You probably want to get enough batteries to run your inverter - and the associated surges from motor starts.

Larry
« Last Edit: January 25, 2018, 09:12:51 PM by ClassicCrazy »
system one
Classic 150 , 5s4p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system two
Classic 150 ,5s 135 watt Kyocero , 16s Calb 100AH LiFePO4 , Outback VFX 3648 inverter
system three
Midnite KID MPPT 24 DC in to  12 volt AGM batterie

Vic

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Re: Layout of a new 800w system
« Reply #34 on: January 25, 2018, 02:39:09 PM »
Hi,  Ed,

Hope that you will carefully consider weather or not to use Aquion batteries,   even if they do return to the market,   AND  have good prospects of being/remaining a viable company.

You appear to be sensitive to some of the considerations of using them,   but,   they  have had poor surge current performance,   and a few other things that make them different from other batteries that are used for off-grid systems.

Have you had a conversation with former MidNite Solar Tech Support chief,  and later,  Sales Manager (or similar position):  and Forum SuperModerator, Halfcrazy (Ryan):?

He was an initial Beta Tester for Aquion,   testing the first version,   and later their improved batteries.  The Link below is for his MN Forum Profile:
http://midniteftp.com/forum/index.php?action=profile;u=2

Please send him a PM. He has decades of experience in the Solar Industry,   having been an Installer,    and a generous resource of information,   here,   and elsewhere.

Just FWIW,  Good Luck,   Vic
Off Grid - Two systems -- 4 SW+ 5548s, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 3X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  Thanks MN for Great Products/Service/Support!

Robin

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Re: Layout of a new 800w system
« Reply #35 on: January 25, 2018, 07:08:38 PM »
I did not have time to read through all the threads, but Larry gave you some good info on Aquion batteries. I would say to avoid them. Too expensive for what they do. Unless your cabin is really large, they also take up a lot of room. The only real reason to buy them is if you want to keep lead and acid out of the environment, but since batteries are 99% recycled, that doesn't make much sense.
No inverter is going to limit power until you reach its maximum. They just don't work that way. It would tend to burn up loads. If your batteries are going to freeze, that is a big problem. You are on a limited budget, but have some interesting issues. It doesn't sound simple if foolproof is what you need.
Robin Gudgel

UpNorthMan

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Re: Layout of a new 800w system
« Reply #36 on: January 27, 2018, 10:04:57 AM »
Thanks for the feedback!  Aquion batteries sound out unless the price goes down or performance goes up.

As far as code, NEC is what my main concern is. The township that the cabin is located in follows Minnesota building code. No local code.

As far as the inverter size, 3600w plus inefficiencies does sound like my batteries are to small. That has been a concern since conception. That is why 1500w - 2000w inverter was my initial size.

Is there a general rule of thumb for minimum battery size for inverter? battery amp hour/inverter wattage I thought I read somewhere C/8 for FLA batteries, about the same as the charging specs. Is that also the same for AGM?

Thanks Ed
« Last Edit: January 28, 2018, 05:38:07 PM by UpNorthMan »

tecnodave

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Re: Layout of a new 800w system
« Reply #37 on: February 13, 2018, 12:33:37 AM »
UpNorthMan,

Check into composting cocoa bean hulls for heat for your batteries! Us Alaskan's have been using 10 gallon milk cans filled with cocoa bean hulls for auxiliary heat. They compost at 155 degrees Fahrenheit and will scorch the galvanizing off the cans! A couple of cans in your battery box will bring the temperature up markedly!

On referigeration.....I'm using a knockoff of the Danfoss DC powered inverter compressors Referigerator. I have Grape Solar 5.0 cu.ft referigerator's that have Chinese "Coku" compressors.
These  units are native 12 or 24 volt DC input and have a specialized 3 phase inverter built into the compressor. That are very energy efficient as the compressor rapidly cycles on and off, sometimes compressing for only 5-10 seconds and off for 15 seconds. Sounds like the cycling would use more energy but it does not. These two referigerator's use far less power than one smaller AC powered Refrigerator.  By running my referigeration on DC I am able to use a much smaller inverter as it does not run any motor loads......no start surge to worry about. Max startup power is about 90 watts , run time is 46 watts even when the compressor is rapidly cycling.

Unfortunately Grape Solar has since exited the DC referigerator business but they are not the only player. The SunDanzer is probably the best of them using  the Danfoss DC powered compressor, but they are also not the only player. This technology is widely available in third world countries, but has been slow to be adopted here. Sharp makes very nice units but they are not yet available in the america's yet,widely used in south-east Asia to the phillipines.

As far as I know the Danfoss and Coku compressors are virtually identical. Danfoss is Scandnavian so would probably be better in quality than the Chinese Coku, but I have had no issues with the mechanical or electrical parts of the Grape solar units. I broke the freezer door hinges on my first unit and there is no fix so I am using a styrofoam plug in door to seal the freezing compartment. 

I have only  1kw solar for my motorhome cabin feeding a Classic 150 with 4 units Rolls-Surette L-16 batteries at 482 amp hours.(24 volt) Full time inverter is Exeltech  1100 watt , runs high end sound system and computer gear, big inverter is only used when nessecary....Magna-Sine MS4024AE 120/240 volt 4 kW. To run power tools and deep well pump, mig welder, etc.


I have tried to keep everything at battery voltage but that is not always practical. I have a Sony hi end auto stereo sound system that sounds like junk compared to my Carvers and Klipshorns.....but oh well! I put up with the Sony which will drive the Klipshorns but does not have that wonderful "Carver Sound" to save energy sometimes. Sacrifices need to be made sometimes.

David.
#1 Classic 150 12 x Sharp NE-170, 2S6P, 24volt L-16 Rolls-Surette S-530, MS4024 & Cotek ,  C-40 dirv.cont. for hot water
#2 Classic 150 12 x Sharp NE-170, 2S6P, 24 volt L-16 Interstate,Brutus Inv.
#3 Kid/WBjr 2 Suntech 280 24v AGM 105 a.h. Exeltech Inv.
#4 Kid/WBjr 2 Suntech 280 12v AGM 105 a.h.

ClassicCrazy

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Re: Layout of a new 800w system
« Reply #38 on: February 13, 2018, 11:43:10 AM »
There is an Amish company that is making DC fridge/freezers using those efficient Danfoss compressors I think.  One of their models has two compressors so you can make either compartment into either fridge or freezer mix or  match .  Better call them for more info about which model is made by them because they were also  still selling some of the older DC freezer units that were made in China ( I think they bought out that company ?)

I met them at the Midwest Renewable Energy Fair and their work looked quality .  And no the Amish around here in Wisconsin do not use solar but the Amish in Indiana do - at least for their refrigeration needs.  So that is why they like using DC direct since they can put up simple systems and not use AC inverter ( don't tell them there is one in the compressor  -  ha ha ! )
http://www.thesolarfreeze.com/SolarFreezer.html

Larry
system one
Classic 150 , 5s4p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system two
Classic 150 ,5s 135 watt Kyocero , 16s Calb 100AH LiFePO4 , Outback VFX 3648 inverter
system three
Midnite KID MPPT 24 DC in to  12 volt AGM batterie