Hi,
I'm looking to put together a new 12VDC Off Grid system using Grid panels.
So far I have 2 of the following Panels. But plan on getting another two soon and eventually 8 all up.
They are 250Watt panels.
So 500Watts, then 1KWatt, & finally 2KWatt's is the plan.
CSUN 250-60M (250 Watt) Voc[V] 37.3, Vmpp[V] 30.1, Impp[A] 8.31
http://www.chinasunergy.com/en/product/96 (http://www.chinasunergy.com/en/product/96)
Here are my questions.
- I'm confused as to which is the best way to go as far as panel strings are concerned.
Do I string in series groups of 4? Or parallel up pairs of 2?
Which is going to give the better results?
I note that the web calc tool suggests that 4 in series is too high a Voc for the Midnite 150.?
- If I parallel up series strings of 2 how does it effect things if the different pairs put out different voltages due to shading etc?
- If you go up in size from the Midnite 150, 200 etc the current handling ability drops. But am I better off using the 200 model so I can run strings of 4 instead of two?
- Can I over size the panel array and just drive the Midnite 150 to full capacity sooner in the day without damaging it?
- Once the batteries are full, can I use the Midnite to divert output to a small Grid Tie inverter that takes a 12VDC input to pump back into the grid?
- Anyone know a good distributor in the USA that will ship to Australia. (Australian distributors are always way too expensive compared to the USA as specially with the great exchange rate currently).
- Are there any DIY MPPT Kits I could use as a temporary stop gap that could handle the initial 500Watts of panels? (The sooner I can save on Grid electricity the more money that can go into Midnite products).
Any help appreciated.
.-.-.
Unless you have a looong distance to send the PV output you would be better to put all 4 panels in (correction, too early) parallel.
That way there is the least amount of downshifiting (37v to 12V) for the 150 to do and thus more efficient overall
I don't think you will be able to do the GT along with a 12 V system
for general speak here the expanding of the pvs is the easy part. the hard part is it's not advisable to gradually expand on a battery bank to match the pvs as batteries of mixed age really isn't a good idea to have and batteries need a certain charge % range to be optimal. design for 500w in pv now and you could overcharge later when you have 2kw in pv. or have a larger battery bank up front and undercharge it now. (edited to clarify and correct miswording)
it is also a good idea to go at least in 12v multiples for the battery bank voltage for every kw in pv up to 48v or so. it could go higher if an appropriate inverter is found to operate at the higher voltages. this means that for the 2kw goal you should minimally go to a 24v battery bank. higher battery bank voltages can be so, but i would say 12v may not be a good choice due to high currents being passed even though it can be done.
now off grid may be good if one wants to backup the grid tie connection from outages. if you don't suffer many outages or if they aren't too long, then straight grid tied pv is a good option. (no batteries) this would be more efficient that gt with battery backup. keep in mind generators can also back you up for some time too. the gt with battery backup can be done and there are inverters out there that can accommodate this arrangement. i believe outback power (not australian) and sma offer inverters that can work in this capacity, but they're most likely are others too that maybe i am forgetting about or that i am not aware of.
Hi VK4AKP,
Nice to see you here.
I am going to call you Ken (perhaps am wrong).
Running 4 of the proposed PV modules in series is pushing things, and, will cause any of the MPPT Charge Controllers to run less efficiently. This efficiency loss generates heat, which is not good for any electronics. As noted, running your two initial PVs in series would be fine for a 12 or 24 volt system.
It is possible that you are almost in the exact geographic center of Australia. I do not know the weather there, but the lowest recorded low temps for the previous ten years or even longer is what determines the maximum Voc that will be presented to the CC. But, even is this woriks out below the Hyper Voc for the Cl 150, the efficiency loss would probably dictate fewer than four PVs in series per string.
Some of us are attracted to 12 V systems, because of the ability to run electronics directly from the 12 V batts. In the case of many Radio transceivers, transmitters often work poorly directly connected to 12 V batts which are not being charged, as these radios are designed to operate at about 13.8 to 14.4 V.
As niel stated scaling batteries by adding more later is a bad idea, and attempting to charge large battery banks with too few PVs also works poorly, without a lot of fiddling with supplementary chargers.
In the US, grid tied systems of any kind must be permitted and approved by the Utility. It may be similar where you are.
Welcome to this Forum. Guessing is about over. Vic
Hi, Thanks for all the good advice.
I think I need to explain my background and planning ideas a bit better to give you guys an idea on what I am trying to achieve.
We currently have here a 5KWatt Grid Tie system using an Aurora inverter and 20x 250Watt CSUN Panels. (I bought two extra for the 12VDC Off Grid project.
See: http://forums.energymatters.com.au/solar-wind-gear/topic3608.html (http://forums.energymatters.com.au/solar-wind-gear/topic3608.html)
I also run a Ham Radio station here and a Web server. I will be adding a M4-ATX 12VDC ATX power supply to the server PC shortly to convert it over to 12VDC operation.
For these services it's important to not have any down time during grid outages.
I also have a lot of other equipment. TV's Routers, Cable Modem, Network Switches, Serial servers, AA/AAA battery chargers, lighting, etc that were all purchased specifically for their 12VDC compatibility.
Our feed in tariff is 50 cents a KW. Grid power 24Cents, Controlled (Hotwater etc) 13 Cents.
So it's better to pump power into the grid during the day instead of using it.
For this reason I can also add a top up charger for the solar battery bank that cuts in on the Off Peak 13 Cent tariff from 11PM - 8AM every day.
We are also limited in that the government does not allow us to have a larger grid tie inverter without forfeiting our 50 cent FIT and dropping to only 8 cents (new laws sadly).
Getting lost yet? LOL
However if the battery bank does fill during the day dropping another say up to 500 Watt's into the grid from an extra small in home grid tie inverter would not be noticed as the existing large system never really runs to capacity.
Now lastly I expect at some time in the future I hope to set up a container home on land on a semi local hill top and will transfer the 12VDC Solar system to it. In fact if I am lucky I may even design and build the container home locally and then transport it later.
I do realise 24Volt & even better 48Volt is the way to go. But since I have based all my devices on the 12VDC system as it's been very easy to obtain over the year I'm sort of locked into that.
Perhaps I should aim for only a 1KWatt Solar array and buy batteries accordingly. (I have to look into batteries yet).
But the ongoing cost of things I will have to build in modules.
I am also looking at getting one of these 400 Watt MPPT Wind Generators off eBay (China), and possibly some sort of LPG Stirling electric / Hot Water generator to supplement things.
If I ever win the lotto it will make things a lot easier as far as design wise! LOL
.-.-.
Hi Vic,
Sorry I replied right at the same time you did. LOL
Must be fate! :)
Yes it would be good to have a chat with another semi local Ham and get the good juice on things.
OK Must run. Chat more soon.
~Ken~
.-.-.
Hi Ken,
OK we have a better understanding of what you are doing .. I do not necessarily know exactly what the items are, but know well enough.
I do not know of a GT inverter that works on 12 V, but they may well be on FeePay or elsewhere.
The additional comments that I have are that Flooded batteries (ones with removeable caps) need to be Equalized on occasion. The EQ voltage usually exceeds 15.5 volts -- even higher with cool/cold batts. Some 12 VDC equipment can be damaged by this higher voltage. Some 12 V Inverters will shut down above 15 VDC etc. All of the items that you have and will be using may well take this EQ V. And some sensitive items could be disconnected, and so on.
Sorry for the tardy reply -- we have had a Heat Wave, and have been distracted trying to get batteries recharged while extracting every last watt for A/C systems.
Thanks for the added info. Good Luck, 73 Vic K6IC
ken,
you will need to figure the loads the items on 12v will draw over a 24hr period. this draw is critical from a design standpoint as otherwise you can overshoot or undershoot your goals. overshooting is the better thing to do, but it is more costly too. the loads required by your server are more consistent and predictable, but ham radio is trickier with variable tx times, power levels, and modes of operation that affect the draw. i hope to assume no linear will be involved in this equation or everything is out the window in the requirements area. ;)
it may be better to go for all solar and not count on wind power.
OK My turn to apologise for the late reply. I'm about 1/2 way through the worst flue I've ever had in my life. Bed ridden and coughing blood up even over the past week. Very scary. :(
So the Midnite Classic 150 at US$615 from http://www.wholesalesolar.com (http://www.wholesalesolar.com) looks the go so far.
.AU direct prices as expected no where near realistic sadly.
All items are designed to run from a car at the very least.
So 13.8VDC Given is easily safe. I doubt an extra 1.2VDC (15VDC) will worry anything.
Some of the items I will run.
Note: * Indicates that I can not find info on power tolerance specs yet.
- Motorola Surfboard SB5101 Cable modem - 12VDC 1.25A (From Power supply) *
- Billion 7404VGPX - 10-15VDC 1.6A. *
- Medion MD86407 1.5TB NAS - 12VDC 1.5A *
- 8 port generic 10/100 Network Switch - 12VDC *
- Digi Portservber TS-3+M Serial Servers (4x) - 9-30VDC 0.5A(Max@12VDC)
- Boltek LD-250 Lightning Tracker - 11.8-18VDC 0.8A
- Maha PowereX MH-C9000 Battery Chargers (2x) - 12VDC 2A *
- Yaesu FT-890AT HF Multi band Transceivers (2x) - 13.5VDC +/- 10% 1.5A RX, 20A TX. (Max values).
- Yaesu FT-212RH VHF Transceivers (3x) - 13.8VDC +/- 10% 0.5A RX, 10A TX. (Max Values)
- Kantronics KAM-XL Packet Radio TNC's (2x) - 10-18VDC 0.15A
- Linksys WRT54GS WiFi Routers (2x) - 5-20VDC 3A(@3.3VDC)
- Minitar SB-2200G WiFi Amps (2x) - 12VDC 1.25A *
- M4-ATX DC Server Power Supply - 6-30VDC 250Watts (To run an Intel i5 based server).
- Vivid AJ-15LE1 39cm LED TV - 12VDC 3A *
- 240VAC Inverters (Yet to purchase some larger ones but have a few smaller ones).
- 12VDC 500Watt Grid tie inverter (Variable Current limited)
- DTMF / RS232 / Ethernet DC Switching device to switch units in and out. (Home Brew)
- + Possibly other items.
Current ratings are Max only and often most of these devices don't even draw 1/10th the amount.
I'm going to look into getting another 2x 250Watt panels and start out with a 1KWatt system I think.
Then later on add a wind turbine to help in low solar times.
.-.-.
ken,
you need to determine what you will typically need over your average 24hr period to determine the minimum battery bank size and that determines your minimum pv size. for instance the maha charger may draw over a 2hr period to fully charge some batteries. are you doing this 24/7, 6 hrs every day, or 2hrs every 3 to 4 days? this time interval has a direct impact for every load on your list. some you may want to run 24/7, but most you don't want to. even a router going 24/7 costs quite a bit in pv power needed because that small load is constant over 24hrs, but your solar production may only be over about a 5hr period. don't confuse this with the amount of daylight hours you have because the early morning and early evening hours do not have strong sun. you may get this strong sun the pvs are rated at for a few hours around solar noon. the rest is from lowered amounts of sun insolation added together to equal that of the total full intensity sun hrs. think in terms like amp hours or watt hours. i like to call them full sun hours, but i forget exactly what the proper term is.
btw, if you wish you can save $5 and go here,
http://www.solar-electric.com/misocl.html
Hi Thanks for the good lead on the other company.
Their online ordering system seems much easier in that it allows for PayPal etc as well.
I'm yet to work out how to get the freight costs displayed there though before checking out.
This is something I would need to be sure of before committing to pay.
Now as far as power usage. Well that would be a big ask to work it all out exactly.
Using the monitoring software though I will basically work around What I have available and go from there.
It may be that I will have to bring in the night charging from the mains in off-peak hours or instigate timer / battery voltage based auto shut down of some systems as necessary. We'll look at all that as time goes by.
The server will be the biggest draw I'm sure. But it too will have green modes etc that it can be kicked into.
Looking at what I currently have hanging off the DC supply I see idling at 1.5A @13.7VDC.
That being - The Router, Network Switch, Boltek LD-250, Digi TS3+M, & Kam XL TNC.
Kick in the VHF Radio (1.7A), then the HF Radio (3.3A).
But it's OK. If I have to make sacrifices that's life.
.-.-.
Still haven't heard back from that company with a shipping quote to Australia.
I guess they don't want my cash $$$'s !! :(
Any other good places to shop state side?
.-.-.
You may try www.altestore.com
Ryan
hmmm. i'm surprised. did you try calling them?
Tel: 800 383-0195 (928 526-8017 Outside USA)
Yep, that's how I contacted them.
Called got their answering service. Left my details including phone number and email address.
They have the best price so far so are my preference really if the freight is reasonable.
.-.-.
Just rang them again and got someone this time.
Postage by UPS only option was US$170. So not worth while sadly.
USPS is around the US$100 mark.
Will keep looking.
I keep seeing the TriStar MPPT 60's on eBay going cheap but I really have my heart set on a Midnite Classic 150.
.-.-.
Try DC Soultions in Fairfield Vic, are the agents for Midnitesolar in AU
http://www.dcsolutionsaustralia.com.au/renewables/solar-controllers-mppt.html
with USA dealers price + freight..its almost the same price from DC Solutions, and your helping PV supply chain in AU
Thanks, But they contacted me early in the peace.
Very friendly guy.
Prices no where near competitive,. He even said as much himself. Must make it hard for Midnite Solar to break into the Australian market with their excellent products.
I have put the project on hold for now. However the funds are still sitting there waiting for a solution.
Worst case we will just buy a Tristar.
Some one needs to get the Miodnite Classic 150's into Australia and salable at around the same $600+ mark,.
It's a good price point and I think they would do extremely well here. There is a huge focus on solar here these days.
.-.-.
UPS charges to Ausralia for a Classic are about $65.00 USD.
If you are comparing the price of a Morningstar on E-Bay to a Classic in Australia, there will be no comparison. The distributor in Australia has to pay the freight and also 15% duties. That means the Classic is going to cost more in Australia, but you will have service should it become necessary.
If you were comparing a Morningstar and OutBack in Australia vs. a Classic, I would think prices would be similar. The Classic Lite has a similar price here to the Morningstar and the OutBack FM80 is the same price here as the Classic 150. Are you seeing huge differences in prices in Australia?
If that is the case, then I need to find out why we are not being competitive?
Please provide dealer names, prices and model numbers so we can investigate.
You can always get a good price on a Classic from some of our larger dealers listed on our website too. You would need to spend money to get it back to us if there were ever a problem though. The local distributor is not going to be able to help you if you didn't purchase the Classic in Australia.
Robin
Hi Robin,
If I can get a Midnite Classic 150 (Not the lite version) for US$600 ish (USA street price) + US$65 freight. I'll take one this second.
So far USA distributors are quoting US$170 freight.
And the AU Distributor lists the 150 @ AU$999 but offered $949 via email.
With an advertised price of AU$999 + post on the one and only AU distributor website with a note along side (no stock) please contact us says it all. :(
You guys have a fantastic product. And given the huge interest in Solar currently and booming economy in Australia I would think that you would dearly love a huge chunk of the market here.
.-.-.
ken,
as an aside i would be curious as to how you became familiar with the classic. i don't work for them, but i agree with you that they have some great stuff.
I did some checking on retail prices for you. Things do cost more in Australia. There are transportation costs and import duties. The distributor has to make a profit too, so buying in OZ is just going to cost more. The market is smaller and that also affects price. The distributor will take care of any issues that come up when the Classic was purchased in OZ.
On the other hand, I checked some dealers in the US and they are pretty cheap. I do not know what they charge for shipping.
Here are my findings:
DC Solar Solutions OZ Classic 150 $899 AUD
Solaronline OZ FM80 $990 UAD
Solazone OZ FM80 $1250 AUD
Solaronline OZ Xantrex 60A $1050 AUD
OutBack Marine OZ FM80 $1076 AUD
Looks like all the OZ prices are similarly priced. One brand does not have an advantage over another.
Northern Arizona Wind and Sun Classic 150 $610 USD
Wholesale Solar Classic 150 $615 USD
E-Bay Classic 150 $679 USD
Alt-E Store Classic 150 $639 USD
The Classic 150 seems to be pretty competitive online in the US too. Things are cheaper here, but after paying shipping and duties, how much is being saved? How much does it cost and how long does it take to get a faulty unit fixed whan you have to send it back to the states.
Hard decision.
Hi Robin,
Yes. I have found US$610 to be about the best price so far for a few sellers in the USA.
The problem is the shipping costs. So far all insist on using UPS @$170.
As you have already said, a reasonable shipping cost should be around $65. (This is what I initially estimated it at also).
If I can find a State side seller that can accommodate this and ship at a realistic price then I'm happy to buy *NOW*!
Other wise it's just not worth while. There are so many good deals available online at far lesser prices for alternative brands the gap in pricing is just too great to ignore.
As an individual I don't pay any import duties for any purchases under $1000.
We live in a global market theses days where many people do a lot of their buying online and from overseas.
Wouldn't you like to see your products coming to a thriving Australian market via what ever method is most conducive to promote highest sales.
As for returns, I fully understand that I would have to foot the bill my end should there be an issue.
However I am very confident that Midnite have very good quality control on all units as they leave the factory.
We are also very interested in your lightning surge protectors. But once again, no point in pursuing this if we can't get things freighted over at a realistic price.
There is a huge market here currently for Grid connect systems. And to date the lightning protection side of things seems to be all but ignored by most installers.
.-.-.
I'm not a MS dealer but do ship to AU often from the West Coast. Punching the numbers in my shipping program, it would be $81.00 US insured to ship a classic 150 Via USPS Priority Mail International down under. $102.00 US to ship it Express mail. :) Just my 2 cents worth......
I still think its very important to support the PV suply chain in AU..some people are not so PV saavy and would need the support of a local dealer and support.
lots of DIY want to go off grid and in the scheme of thing balance of system components are around 20% of the install materials.
The big cost in stand alone PV system is the Battery Storage, upto 50% of material costs
my system costs aprox: $5k Battery bank, 2 midnite classics 150&lite $1.9k,
outback VFX3024E Inverter charger, mate & hub $2k (second hand), PVs $5k, PV tilt frames $1.5k (24 190w PVs), sundrys $1k
The Charge regs are the least of your system cost :)
Hi, Yep we've had some success actually.
Have found a couple of distributors with decent pricing on both equipment and freight to .AU
Will settle on one and order within the next few days.
Australian dollar has also started to rise again so this is helpful also to a very small degree.
Now with the lightning protectors. What's the norm there?
We will be doing both a grid feed system (Aurora PVI-5000-OUTD) 5KW panels - two strings, and a off grid (Midnite Classic 150) 1KW panels - parallel or series??.
What's the norm with fitting the Midnite lightning protectors? Which models and placed where on these systems?
Also while I agree it's good to try and support local business. With the global market and online ordering the way it is these days it's just not financially viable on many things.
Batteries. Well due to their weight they will most likely be bought locally.
.-.-.
Quote from: onanparts on October 10, 2012, 03:28:48 PM
I'm not a MS dealer but do ship to AU often from the West Coast. Punching the numbers in my shipping program, it would be $81.00 US insured to ship a classic 150 Via USPS Priority Mail International down under. $102.00 US to ship it Express mail. :) Just my 2 cents worth......
The Midnite SPD's should be placed at the PV combiner if it is more than 75 or 100 feet away from the electronics. For an Aurora inverter, you would use an SPD600. For an off-grid combiner, it would be the SPD300.
The same should be connected at the other end of the combiner wiring right close to the PV input of the inverter or controller.
You should always have an AC SPD on the AC wiring. The grid tie inverter will need just one, but a battery based inverter should have an SPD300 on the AC input and AC output.
Did this help?
Hi thanks, Yes very helpful. Couple of spots there I didn't think about, so yes. Great thanks.
OK. So Midnite Classic 150 has been in transit for about a week+ now. Expect to see it some time next week. :)
Company was out of stock on the SPD's so we will look at that next order.
Also have some local installers very interested in your SPD's.
Only two weeks ago a news broadcast here featured a story on a Brisbane house that burnt down due to lighting striking the solar equipment at their house.
Pretty much all installers here have not even considered the advantages of offering SPD's as part of the installation process.
Now back to my system.
I have two more panels on order so the system should look something like this.
- 4x CSUN 250-60M Panels (1KWatt Total).
- Midnite Classic 150
- 12VDC Battery bank (NiFe - Nickle Iron [Edison Cells]). Size ???
So I have some more questions.
- Should I wire the panels up 4 in parallel, or 2 parallel strings of 2 in series?
- What is the simple math to work out the total maximum charging capability of the panel and controller combination that I will be using for sizing the battery bank (Ah's).
- Any good recommendations on where to buy the NiFe batteries?
- On completion of charging can I set up the Classic 150 to dump any extra available current to an external device to be utilised for other things. Say an external grid connect inverter or heating element for water?
I think that's about it for today.
Thanks for your help.
.-.-.
My Midnite Classic 150 turned up yesterday in the post. :)
Very impressed when I opened it up. Love the cast alloy case.
Shame the turbo fan section of the case is only plastic. The rest is beautiful.
I was wondering about a couple of things.
My unit didn't come with the clip in dust cover for the top of the unit.
I remember watching in one of the videos that this piece was supplied in the kit. ?? Has this changed now??
Also when taking the front cover off I notice a grove in the casing where a seal should go.
Mine doesn't have this seal. Is it missing? Or aren't these supplied standard?
I still have to buy some connectors, cable, and breakers, but can't wait to fire this baby up and give it a go.
Beautiful piece of equipment.!
.-.-.
Quote from: niel on October 09, 2012, 07:12:29 PM
ken,
as an aside i would be curious as to how you became familiar with the classic. i don't work for them, but i agree with you that they have some great stuff.
Sorry I must have missed this post earlier.
Interesting story actually.
We installed Grid Connect Solar here at the house and I was able to strike up a deal with the supplier to get a few extra panels cheap.
Being interested in self sufficiency, ham radio, alternative energy and lifestyles in general I took a punt that I could adapt the panels to charge a 12VDC battery system.
I figured one of two things.
1. I could rewire the internal cell strings of the panels in the junction box by mucking with the 6 bypass diodes and tap points to get a lower voltage suitable for 12VDC charging.
2. Or possibly someone had thought of using the higher voltage grid connect panels for battery charging and had produced a controller already (MPPT).
I searched for weeks actually on eBay and in forums.
I came across a lot of different brands and models.
None of which really gave me the features I wanted.
1. High capacity (1KWatt+ of panels).
2. Good monitoring ability, preferably via Ethernet but I was prepared to put up with just RS485 / RS232 etc.
I was almost going to settle on the TriStar MPPT 60 but I really wanted something larger. Had they of made a 80Amp version I probably would have purchased then and not searched any further.
Anyhow, I finally came across the Midnite Classic 150.
After seeing the features it offered I was sold. I knew that was the controller for me.
Then availability became an issue.
Easiest purchase would have been via eBay. But there are none on there.
I even found the Outbacks & TriStar's on eBay but no Midnite Classic's sadly.
So I started google'ing for suppliers in the USA.
During this time I was also contacted by a very nice chap that was the importer for Australia.
Unfortunately we both very quickly came to the conclusion that he was unable to provide competitive pricing which was a shame so buying locally was not an option.
Most of the USA suppliers insisted on UPS shipping at $170 ish. However I did manage to find two suppliers that were happy to ship using the USPS @ $85.
One company stood out from the rest in a big way.
Friendly staff, very helpful, and competitive pricing.
I actually only heard of them because their company was mentioned in this thread actually.
So I purchased from them and will do again in the future. They are great.
I do remember that it was only a fluke thing that I finally saw the Midnite Classic.
I think maybe more advertising is needed perhaps.
.-.-.
I have a new question.
It looks like I will end up with 6x 250Watt panels. Giving 1.5KWatt total.
I was going to split these as 2 strings of 3 panels in series each. (VMP 90.3VDC).
But the online calculator says 1.2 Classic 150's required and in red "Excessive"
Now I don't mind it being excessive because it will be located in a far from perfect location. (Flat mounted / no tilt, & shading issues).
But my question is will this configuration "Not hurt" the Classic 150?
Will it just harvest at it's peak capacity at any point where more then 96 Amps are available?
With this panel configuration, Max ability for a Battery @14.4VDC is 104.2 Amps.
.-.-.
1.2 times the Classic will not hurt it you will just go into current limit.
Ryan
Hi Guys,
Still collecting bits for my solar project, but I'm getting closer. :)
Batteries.
Latest items obtained are 3x deep cycle lead acid batteries. (Panasonic_VRLA_LC-XA12100P [100Ah 12VDC]).
These are second hand ex government about half way through their life.
http://www.panasonic.com/industrial/includes/pdf/Panasonic_VRLA_LC-XA12100P.pdf][url]http://www.panasonic.com/industrial/includes/pdf/Panasonic_VRLA_LC-XA12100P.pdf (http://[url)[/url]
Eventually I still want to go to Nickel Iron cells but for now these will get me started.
I'm just wondering if it's OK to Parallel up two of these batteries to give me 200Ah combined?
Or is that a bad idea due to mismatched characteristics of each individual battery?
Panel wiring and voltage into the Midnite?
Also I'm currently shopping for MC4 connectors and "Y" cables.
Eventually I'll run all 6 panels in parallel to keep the volts down to under 40 VDC but for now is there much loss in the conversion process if I run all the panels in series for easy initial wiring?
~TNX~
Ken
.-.-.
BUMP BUMP BUMP
HUmm. :(
Is Midnite Solar still trading?
Your forum says no new posts since my last visit? :(
And messages seem to go unanswered.
Latest my way is I am looking at a Powerstar W7 (12VDC 3000/9000Watt inverter charger) to add to the system.
Just wondering if anyone has had any experience with these?
.-.-.
Quote from: vk4akp on July 03, 2013, 10:45:12 AM
BUMP BUMP BUMP
HUmm. :(
Is Midnite Solar still trading?
Your forum says no new posts since my last visit? :(
And messages seem to go unanswered.
Latest my way is I am looking at a Powerstar W7 (12VDC 3000/9000Watt inverter charger) to add to the system.
Just wondering if anyone has had any experience with these?
.-.-.
This is a fairly old thread. 8 months on most forums is an eternity and posts fall off the edge as it were.
Midnite is still very much alive and kicking.
Maybe nobody knows the answers you seek?
This forum is quite active, several posts every day so you should see some "new posts". Perhaps you need to flush your cookies for the Midnite forum? That is usually the cause of "no new posts"
Sorry, I have never even heard of that inverter but 9KW at 12 volts will need huge cables for battery connections when it peaks at nearly 800 amps. Just a general observation.
What do you mean by "messages go unanswered"? If you mean posts here on the forum it is likely nobody knows the answers. If you mean personal messages to members they may not know the answer, either. If you mean email then maybe they got missed?
Good luck sorting it out.
Tom
Hi Ken,
Nice to see you back here.
RE MidNite, there are numerous posts per day here. All is well, alive and active here, as I see it.
Folks who make 12 V Inverters with specs like this (was unable to find any real hard specs) should NOT be trusted in my opinion.
As Tom indicated, the currents involved to make even the 3 KW are huge -- around 300 Amps. It is very difficult for an inverter to handle these large currents internally. At 12 V, the voltage drops are very significant inside the inverter, let alone the cables and effects of these high currents on the batteries.
Generally, if you need these power levels, a 48 V system is in order. Just my opinions, 73 - GL, Vic
Hi, Well it's good to see you guys are still going. I love your products. It's a big shame the classics can't be distributed in Australia at a more affordable price.
I wonder why when I log in it says no new posts since your last visit. Oh well.
OK, Yes I've been searching and searching on these Powerstar W7 inverters and have come up with some YouTube video's that are saying they have terrible standby current usage and a Energy Matters forum thread where they have tried to replace the standard transformer with a toroidal. These people found that the more you loaded the thing up the more the sine wave tended to turn into a very dirty looking square wave. :(
This is a shame as they are at a reasonable price.
OK And I understand what you are saying about the larger inverters at 12VDC.
Unfortunately at this point I don't want to go to a higher DC voltage system as most of our devices will be running from 12VDC.
Most of the high draw 240VAC devices should come in at over 1KW but most likely under 2.5KW so I might look for 2x smaller inverters instead of just one big one.
What to look for and where is now the big question.
Looking on eBay just seems to reveal a lot of junk like the Power Jack range etc.
I'm also finding it hard to find a source in Australia for affordable DC breakers.
As specially a couple of big ones say 100Amps for the panel and battery disconnects.
.-.-.
If wanting to use 12 volt system, the Xantrex Prosine 1800watt inverters are used a lot in motorhomes & caravans, friends of ours have a 20 x 10foot shed with 2x200amp hour batteries, 4x190 watt panels & Prosine 1800 inverter..seems to work ok, can drive a microwave and toaster etc.
As suggested the Powerstar W7 inverters are CRAP!
Couple of things ive learned.
1. Stay away from cheap inverters. You want to sleep at night right?
2. Stay away from cheap breakers. You want your loved ones to wake up in the morning.
3. 12V at 3KW, thats just silly. If you have 12v gear thats an even better reason to use 24V. A 12 batt is gona range from 12v to 16v. 24v to 12v dc converters are so cheap and efficient, and you get exactly 13.8, or 12 if thats your desire, all the time. And freeing yourself from this 12v limitation means no more asking: it is 12volts when you buy something. Adjustable converters you can run anything. Doubing the voltage means halving the current and quaddupling the power loss in cables. Better choice of inverters at 24v.
Btw who was it you found freighted down here reasonably? If you think 800 was bad for aus prices here in nz ours was 1100 and that was the lite!
Hi again,
One complicating factor in using DC/DC Converters CAN be that some are poorly EMI/RFI suppressed (if at all).
The quality of converters may have improved since I looked at them, however. Ken is a Ham Radio guy, and switchers fairly often cause NOISE.
On the other side of the 12 V argument, is what has already been stated -- direct battery voltage varies far too much for many devices, not the least of which are 12 V HF Transceivers. Have heard from some who were using "12 V" LED lights that were toasted by cool batteries, etc. Hammie transmitters often will not make nearly full output power directly from a fully charged 12 V battery which is not being charged at the time, and quite often the transmit distortion increases strikingly even at 12.5 V DC input. Believe we have said this before, here.
Anyway, here, we have NO direct DC loads other than Inverters, and anywhere DC voltage is needed, it is made from 120/240 VAC.
And, Ken, regarding the "New Post" indication, here, it seems to be often delayed by hours from when the post was made.
73 GL, Vic
the other option is to have a small 12v battery that is kept charged by a ,say Morning star PWM, CC off the 24 or 48V battery...
Hi ken
Where are you & where r u shopping in aus?
Wouldve thought local price would still beat import +shipping+ duty etc.
I got mine at a reasonable rate mayb i can get annother :)
Why dont you go 24v & make up a linear 12v supply off that rather than switching for the noise factor. I assume a hammy could manage that.
Drop me a msg if you like to discuss how far youve got.
In victoria here
Cheers
Mark
Hi, Wow. So many posts recently all of a sudden. :) I'm starting to like this forum. :)
OK. I got a very good deal. I've had my Midnite Classic 150 sitting here for some time now still in it's box.
So things might have changed a bit since I purchased.
However all up including freight delivered to my door - AU$625.
To get this price I had to get them to use normal USPS postage though.
Most places will want to use very expensive freight companies.
However I have always found USPS to provide a perfect service.
I can see I'll have to put some more thought into things.
I would have thought that most 12VDC devices would tolerate a 12-16VDC range.?
However I can see the advantage of running a higher battery voltage and then converting down to get a good fixed exact 13.8VDC.
This does however make me wonder about the costs and reliability of 24 - 12VDC converters. As specially when we are talking high current for many items. HF Radio can draw 25Amps each for example on transmit.
I do currently have 2x 12VDC Panasonic Lead Acid deep cycle batteries. So I could run them in series to get the 24VDC.
However when I finally go to NiFe cells it would mean having to buy twice as many batteries. :(
Ideally way down the track a 48VDC battery back would be the go I feel for the heavier load stuff like big inverters etc.
But that's way off due to the costs involved.
Xantrex Prosine 12VDC 1800W model looks interesting in the mean time.
.-.-.
Be careful of High battery voltage on the HF radio. Most of the ones I have seen have a 15v Zener across there leads that will short out at 15v dc. I would prefer to go 24v and use a dc to dc converter for the radios
Ryan
Yep that was a very good price all right.
Last time i checked my radio gear didnt like more than 15v
Good luck
OK. HI guys again!.
Your going to hate me because I am still thinking 12VDC for our initial system but with NiFe batteries.
There are a lot of reasons for this choice. But I do realise that if money was no object that 48VDC would be the go 4sure! ;)
So.. My next question.
If we go with a 12VDC battery system, I totally understand the variable voltage range problem. As specially with regards to NiFe.
So what's available product wise or even just circuit / educational wise with regards to a DC to DC converter @ 12VDC?
Something that would handle the range of 10 - 16VDC input and smooth it to a nice 13.8VDC output? Lotz a amps! ;)
TNX
.-.-.
Quote from: vk4akp on July 31, 2013, 12:28:41 PM
So what's available product wise or even just circuit / educational wise with regards to a DC to DC converter @ 12VDC?
Something that would handle the range of 10 - 16VDC input and smooth it to a nice 13.8VDC output? Lotz a amps! ;)
This is not really easy, because you have buck converters and boost converters, and they both need a bit of leg room. The kind of converter that can handle the situation where the input and output are close is a auto buck/boost. ie it can operate in either mode. They are less common, more expensive and less efficent. Is that what you wanted to hear?
What device is it that needs 13.8V?
Have you considered a 12v DC laptop powerpack? The one I have you use a coloured plug to change the DC output voltage.
OK Thanks, Can you point me to some supplier links for these buck / boost devices please?
(Actually.. Edit: I just found a few on eBay. 97% efficient so not so bad. Largest is 150Watt though. Would need 300 Watt).
Eventually I will go to a higher voltage.
But for now it's going to be a 12VDC system because.
- Less batteries needed to set up and cost will be an issue due to going NiFe.
- Top up generators are easier to get with a 12VDC charge port as opposed to 24 or 48VDC.
- Will be adding a DragonFly wind turbine. But it is auto sensing 12/24VDC.
- Also looking into making a gasifacation unit to produce synth gas to run the top up generator. So cheaper generators are the go as I expect the gas to be a bit dirty and most likely run the generators out early. ???
Because the Midnite is so flexible and same with NiFe I can simply add more cells later on to the project to eventually go 24VDC.
.-.-.
Quote from: zoneblue on July 31, 2013, 03:17:07 PM
Quote from: vk4akp on July 31, 2013, 12:28:41 PM
So what's available product wise or even just circuit / educational wise with regards to a DC to DC converter @ 12VDC?
Something that would handle the range of 10 - 16VDC input and smooth it to a nice 13.8VDC output? Lotz a amps! ;)
This is not really easy, because you have buck converters and boost converters, and they both need a bit of leg room. The kind of converter that can handle the situation where the input and output are close is a auto buck/boost. ie it can operate in either mode. They are less common, more expensive and less efficent. Is that what you wanted to hear?
For more amps you just parallel them. Make a cursory check of the voltage on each to make sure they are pretty close. Works fine.
I've read through this post and am curious why you are choosing NiFe Chemistry as opposed to the typical Lead or even the LiFePO4 that I have been using in my system?
Hi Cniemand, Well I've actually ended up with some second hand ex government Panasonic lead acid batteries to start out with.
I'll use these until they fail and then I'll move across to the NiFe (Edison Cells).
My main reason's are...
- longevity (Life of the batteries) often these types of cells can be passed down through the generations and still be functional.
- Virtually indestructible. You can even boil these things dry and still not kill them.
- Non acidic. Nothing worse then dealing with acid environments. Acid tends to creep into everything around it.
- Stacking. Unlike lead acid etc. You can add extra capacity by paralleling batteries to older pre existing banks without harm.
You'll find this good reading on the subject.
http://www.nickel-iron-battery.com/ (http://www.nickel-iron-battery.com/)
And some good product literature from one of the major manufactures here.
http://www.changhongbatteries.com/down/index/51c6482e4c9c74edf078767c5cf80eaf.pdf (http://www.changhongbatteries.com/down/index/51c6482e4c9c74edf078767c5cf80eaf.pdf)
At the moment I'm sad to say that the project has actually stalled.
Currently I still need to source some good DC switches for isolating the main array, batteries, & load. Also chasing a source for wire.
Hopefully we will see this project kick started again before the end of this year.
.-.-.
Thanks! Was curious.
- Cloud
vk4akp,
I have been using SAMLEX brand DC to DC converters for some time now and am very pleased with their performance, my base solar system is 24 volts and most of my loads are 12 volt DC. I use a SAMLEX SDC-30 (about $130 USD) which provides 30 amps at 12.6 volts DC very clean, ripple <50 mv. From 20-32 volts DC from my L-16 battries. I am a communications buff but not a ham radio operator so I have researched which one is lowest EMI-RFI. These are widely used in the communications industry to power land mobile two radio gear in construction vehicles. I also have some lower quality units that power the 12 volt heater elements in my absorbsion refrigeration from my excess p.v. Power made by Pyle ($37 USD) that are much cheaper but much more EMI/RFI.
Samlex also makes same voltage isolated converters that are buck/boost and I have a IDC-360A-12 that is 9-18 volts DC in and 12.6 volts DC out. 30 amps . Very good regulation but that one was $360 USD
I also have gotten many years out of my XANTREX ProSine inverters. My main solar inverter is the 1800 watt 24 volt to 120 v.a.c. Unit and my service truck has the 12 volt 1000 watt and 1800 watt ProSine units, never had a problem with them but the Exceltech is preferred in professional communications because their sine wave is one of the best there is. If I had to replace a pro-sine I would get the Exceltech due to their quality and awesome service department.
Hope this info helps, cheers from the left coast,
tecnodave
Edit......SAMLEX makes DC to DC converters up to 60 amps output.....
..SAMLEX America in B.C. Canada
Thanks for the info TechnoDave!
OK So it's time to go eBay shopping again and try and get some of these panels up on the roof finally.
I'm looking at cables and disconnect breakers today.
System
6x 250Watt Panels in parallel. <<- (Sorry. edit. I'm tired) LOL! Not series. Parallel
Classic 150
2x Panasonic LC-XA12100P (12V, 100Ah/20HR) [In parallel (12VDC)]> Good quality made in China ok Joe! ;)
Rated PV Array current is 47.22 AMPS
Max Current at 14.4 (Battery) 104.2 AMPS
Max VOC 44.4 VDC
6mm cable is harder to find.
I've found a supplier selling 4mm thick x 450mm long with MC4's for about $4 each. (Suitable?)
With the MC4 branch joiners are the plastic "T" type as good as the wire "Y" type?
Now for the Panel string circuit breaker I have found these
(50 Amp, 500 VDC Din rail mountable, Noark)
http://www.ebay.com.au/itm/50A-DC-Breaker-Solar-Isolator-50-Amp-500V-Circuit-Breaker-dual-pole-2-pole-/261247129685 (http://www.ebay.com.au/itm/50A-DC-Breaker-Solar-Isolator-50-Amp-500V-Circuit-Breaker-dual-pole-2-pole-/261247129685)
For the battery I haven't found anything yet.
I would prefer din rail. But might mount something closer to the terminals like this.
(200 Amp)
Specifications:
Max. voltage: 42V dc
Interrupt rating: 3000A @ 30V dc
Operating temperature: -32°C to 82°C
Material: UL94V-0
External dimensions: 70 x 50 x 35mm
http://www.ebay.com.au/itm/200A-DC-Circuit-Breaker-high-current-Isolator-200-Amp-surface-mount-single-pole-/390591666445 (http://www.ebay.com.au/itm/200A-DC-Circuit-Breaker-high-current-Isolator-200-Amp-surface-mount-single-pole-/390591666445)
Comments please?
.-.-.
Hi Ken,
A quick post -- a storm is due in a few hours ...
First, you do not want to connect all of the PV modules in series (as I read the above post). This will probably exceed Max Vin spec for the Classic 150. Most PVs in this power range have a Vmp of about 30 - 31 V, and a Voc of around 38 V or so. You could run two strings of three in series, and not need a Combiner with fuses/breakers. This 90-ish (I assume) string Vmp is a bit high for a 12 V system. The Classic would be a bit more efficient with three strings of two, with a Combiner and DC rated breakers for each string.
The first link is for a Ganged Dual breaker, probably not what you need. MidNite (and Outback power for that matter) sells a line of DIN breakers specifically made for Solar applications, try to find these locally.
Also, try to stay away from the surface mount breaker in your second link. These are Thermal breakers, and do not really have enough current Interruption ratings for battery connection -- YES some folks do use them, but, there is a lot riding on the ability of this breaker to break Fault currents if something shorts ... a fire could result.
Here are some of the MidNite Breakers, this one is used commonly for PV strings:
http://www.solar-electric.com/mnepv.html
They make breakers for the CC to battery -- this one is a DIN Double Wide:
http://www.solar-electric.com/misomn150vdc.html
These breakers are nice for PV main breakers (although the DINs are fine for this) and for CC to battery:
http://www.solar-electric.com/pamodccibr.html
Realize that you are down under, and it is difficult to buy internationally, but these links are an example of the Real Deal breakers that are rated for the task of Solar use.
All of the above breakers are rated for Continuous use at rated current without tripping. Your rated PV power might possibly on rare occasions exceed 100 A, but this is unlikely. To meet the Codes in the US, the breaker on the CC output would need to be up-sized to 125% of the rated current. I am not a Code expert. On your system, you will need to use a large diameter cable between the CC, breaker and battery.
More later, 73 GL, Vic
Back again.
Still plugging away collecting bits for the install here.
Got some roofing screws donated for holding the rail brackets to the roof so that's a few $$'s saved. :)
Still need to find a affordable source for DC breakers. 100Amp ones are close to impossible to find here :(
(Edit: Thanks for the DC breaker links. Looking into it now. :) )
And some cable. Maybe just eBay for that.
Anyhow reason for my post is I've bought a new toy to add to the mix.
eBay kept sending me discount vouchers and I found a discounted Wind turbine with make an offer on it as well.
All up with all the discounts I ended up getting a 400Watt turbine with controller for AU$305 including shipping.
Pictures here: http://shazam.zapto.org/igal/wind-turbine-1/ (http://shazam.zapto.org/igal/wind-turbine-1/)
So here comes the questions. ;)
It didn't come with a dump resistor. I am wondering what can be used there? I'm also wondering about using a water heating element to dump unneeded power into the hot water system as free heating. ? Trouble with this idea is there would have to be a thermostat to disconnect the element at a set temperature. At which point it no longer works as a dump load resistor?
To totally stall the blades, do I just short the dump load resistor lines? Or is that a no no.
Yes you've probably guessed the Chinese instruction manual is close to useless. And I am new to wind turbines. LOL!
The controller is quiet strange. It is a hybrid thing. Allows for a solar panel up to 300 Watts + a wind turbine up to 400 Watts.
It also supposedly senses if it's a 12 or 24VDC battery. ¿¿¿ :o
Anyone seen these before? Comments??
If I use my Midnite Classic for the 1.5KWatt grid panels and the new wind turbine controller on the same battery, how will that effect things?
Which is more bird friendly. White or Black blades?
(http://shazam.zapto.org/igal/wind-turbine-1/.slide_IMAG0008%282%29.jpg)
(http://shazam.zapto.org/igal/wind-turbine-1/.slide_IMAG0011%283%29.jpg)
(http://shazam.zapto.org/igal/wind-turbine-1/.slide_IMAG0013%282%29.jpg)
.-.-.
Are you sure that hybrid controller does not have a dump load built in? That's a lot of heat sinking fins surrounding it AND it appears there is an led to indicate BRAKE which sort of implies a load resistor or maybe a shorting relay being used to slow or halt the turbine.
I would tend to not consider water heating with this as real power output in anything less than a major storm is likely too insignificant to be useful.
Dgd
OK, I've had a bit of a chance to catch up with the reading.
Vic - Those DC breakers look good. And the price is about a third compared to the last time I looked so good one thanks!
I as specially like the ones from the first two links.
Midnite Solar MNEPV 150 VDC 80A and 100A Solar Array Breakers - Will use this for he array breaker (As suggested).
The wiring confuses me though. Looks like both switches are combined to try and share the load or something?
Shouldn't solar panels be totally isolated when switched out?
MNEPV Midnite Solar MNEPV 1 to 63 Amp 150 VDC Breakers for Solar Panel Arrays - And will use some of these for the DC fuse box to break out to different DC outlets in the different rooms.
I notice that you reference http://www.solar-electric.com (http://www.solar-electric.com) as the supplier. I have been dealing with http://www.altestore.com (http://www.altestore.com) previously. Any preferences which might be the better one to go with?
I've also decided to run all the panels in parallel. Cable combiners have become a lot cheaper over time and I prefer to work with lower voltages so I'll be doing it that way which is better anyhow.
I might also only start out with 4x panels (1KWatt) for starters as I'm tempted to play around with the other two using Aurora Micro grid tie inverters at another location for a bit.
dgd - I just assumed by the picture of the bulb on the controller that the Yellow Wires go to a dump load resistor?
I'll try emailing the supplier again but their English and listening ability is fairly poor.
As for the lights on the thing. Yes it's like a Christmas tree. LOL. And there is even an IR LED on the thing marked Infrared Communicator. The documentation says nothing about this. Nor is there a remote.
I also have to try and find out some math on what wire I can use that will handle the currents etc.
OK More later. It's almost 4AM here. Burning the Midnight Oil. LOL
TNX 4V advice! Much appreciated.
.-.-.
Quote from: vk4akp on September 10, 2014, 01:53:56 PM
OK, I've had a bit of a chance to catch up with the reading.
Vic - Those DC breakers look good. And the price is about a third compared to the last time I looked so good one thanks!
I as specially like the ones from the first two links.
Midnite Solar MNEPV 150 VDC 80A and 100A Solar Array Breakers - Will use this for he array breaker (As suggested).
The wiring confuses me though. Looks like both switches are combined to try and share the load or something?
Shouldn't solar panels be totally isolated when switched out?
MNEPV Midnite Solar MNEPV 1 to 63 Amp 150 VDC Breakers for Solar Panel Arrays - And will use some of these for the DC fuse box to break out to different DC outlets in the different rooms.
I notice that you reference http://www.solar-electric.com (http://www.solar-electric.com) as the supplier. I have been dealing with http://www.altestore.com (http://www.altestore.com) previously. Any preferences which might be the better one to go with?
I've also decided to run all the panels in parallel. Cable combiners have become a lot cheaper over time and I prefer to work with lower voltages so I'll be doing it that way which is better anyhow.
I might also only start out with 4x panels (1KWatt) for starters as I'm tempted to play around with the other two using Aurora Micro grid tie inverters at another location for a bit.
Hi Ken,
Thanks for the update.
YES, the DIN-Rail 80 and 100 Amp breakers use two breakers linked mechanically, and wired in parallel. These are most often used on the output of a CC -- the connection to the battery.
Normally one would the single gang MNEPV breaker for the PV input, as these single breakers have ratings to 63 Amps, which is usually fine for the PV input to the CC and they will be completely isolated from the 80 or 100 A breaker.
I do believe that a number of Down-Under folks do use alt-e as well as wind-sun. It is mostly down to reliability/reputation of the company, the shipping costs, , item price, customer service, etc.
Often use wind-sun here, as they have very good pricing, quick service, and are reliable. Have never used Alt-e. Do also use Colorado Solar (SolarPanelStore), and they are very good, but often ship from Distributors, FWIW.
Fine on running all PVs in parallel, sounds fine to me, although, as your PV array grows, the cable size will become large, due to the higher current from the low voltage of single PVs in parallel.
Have Fun, please keep us posted. 73 GL Vic
_..._._
Hi, Only a quick one tonight. Late already and we have a big weekend ahead including a Ham Fest at the coast! :)
But you've got me thinking again. Making more shopping lists.
I'd really like to see the system installed before 2015 which of course is when the UFO's start landing! ;)
Any idea how to work out the current ratings of the cabling?
I'll be using the industry standard 4mm cable and MC4 connectors as used on the grid connect stuff.
The solar panels are already factory fitted with this so I'll make the rest of the run the same.
So that has me wondering about current ratings?
I ran the Midnite Classic Sizing Tool and it came up with 49.86 Amps @ 30.1 VMP for 6x CSUN-250-60M 's in parallel.
Or 24.93 Amps @ 60.2 VMP for paired series paralleled.
The cable run from the panels will be definitely under 10 Meters, possibly even less then 6 Meters.
Now on another note, when it comes to cabling up the panels even just to get 4x on the roof for starters (paralleled) it looks like I will need 3x pairs of "Y" cable's (6 total) & 4x 1 meter patch cables. (Each Panel is 1 meter wide). See: http://www.csun-solar.com/fileadmin/dateiablage/media/datasheets/m-mod/en/CSUN250-60M_ENG.pdf (http://www.csun-solar.com/fileadmin/dateiablage/media/datasheets/m-mod/en/CSUN250-60M_ENG.pdf)
From this point the final run of cable from the roof to the panel isolation switch at ground level. (5 - 10 meters).
Brings me to another questions. Does it harm panels leaving them open circuit for long periods of time? IE If I install and wire up to the isolation switch and then leave that disconnected for a time while building the weather proof hut to house the Midnite Classic etc.
Now back on to DC breakers.
I've found these http://www.cnakm.net/125a-DC-Miniature-Circuit-Breaker-MCB-Mini-Circuit-Breaker-p15061227.html (http://www.cnakm.net/125a-DC-Miniature-Circuit-Breaker-MCB-Mini-Circuit-Breaker-p15061227.html)
http://img.leadong-web.com/html-en/image/25-vZKfVdcWIDQw-1-1.jpg (http://img.leadong-web.com/html-en/image/25-vZKfVdcWIDQw-1-1.jpg)
AKMAN YJB1Z-125
125Amp DC
1P 220VDC
2P 440VDC
Under AU$20 each delivered. :)
What do you think? Buy 3? One for panels, one for between the Classic and the battery, & one for the load off the battery?
Oops, brings me to another question! LOL.
Batteries are 2x paralleled 12VDC Panasonic LCXA12100P (100Ah/20h).
http://industrial.panasonic.com/www-data/pdf2/ACD4000/ACD4000CE120.pdf (http://industrial.panasonic.com/www-data/pdf2/ACD4000/ACD4000CE120.pdf)
Whats the maximum current you can pull from these without hurting them?
The spec sheet doesn't really say.
But it's highest current draw info suggests 55Amps for 1 Hour?
So with 2x paralleled I guess a 100Amp breaker is probably enough?
Eventually I plan to go NiFe batteries anyhow. But I have these Lead Acid Panasonic's already and they were only $20 each ex government second hand so worth using to start out with.
OK Sleep time me things!. TNX all! :)
.-.-.
Hi Ken,
Regarding the cable run from the PVs. The 4 mm cable that you mentioned, assume that this is 4 mm Squared in cross sectional area, or about 9.5 AWG ?? If this is the case, it is probably too small for the run from your COMBINER box to the power room.
You WILL need a combiner, with three or more PVs. This combiner will have one circuit breaker (best) or fuse per each PV to protect against fire hazard from a shorted PV.
Circuit breakers really protect the cable that attaches to them. So, you will want a considerably smaller breaker than 125 A. Your 250 W PVs will hare a Max Fuse size stated on the label on the back of the PV module. Often it is 15 A. Hope that you can find the CBI/MidNite breakers at a reasonable price there ... they are designed for the Solar service, and fit into the MidNite boxes, which are also rated for the Solar applications.
That Pana battery appears to be Gel, and probably really intended for UPSes. Usually not good to use Gels for cyclic PV applications. They are very picky on charge voltage and have a limited ability to take high charge currents. And, if this is a UPS battery design, it will not be very good for very many cycles. These usually just want to be on Float 24/7, with an occasional, short cycle when the AC power goes down.
EDIT: You may not see this Ken ... but forgot to mention that PV modules will not be harmed by mounting them and leaving them disconnected, or otherwise not delivering power. There is a very small reduction in the output that is caused by exposure, and there are slight risks of physical damage that might not happen, if the PVs were stored in their original packaging, etc, but in general, you should have no worries.
More Later, Thanks, 73, Vic
Hi Vic,
Thanks for all the good info.
So I can't combine the 4x panels up on the roof under the panels using "Y" cabling?
Is this because the combined current would be too great for any sensible sized cable run?
So for 4x panels I have to run a total of 8x 4mm^2 cables down to a combiner box with individual fuses on each wire (8 fuses) in a combiner box?
Then combine into very thick wire (Like on the starter motor of a car) into a main breaker fuse that should be a bit over the combined max current capacity of the panels?
And the same very thick wire to the "Classic" and to the batteries? (Large breakers in between each? Possibly 100Amp).
Maybe there is a video on this somewhere that I can watch on setting up an array like this?
Shame there are no hobby groups anywhere doing classes etc. Like for making mud brick homes etc.
Batteries were almost a gimmie @ AU$20 each. So I will just run them till they fail and save in the mean time for some NiFe batteries to replace them. Still deciding on a battery supplier from China. There are a few now. Plus it's a big investment. If I go over AU$1G for the purchase I pay import duties as well. So some things to look into yet.
Spec sheet says the panels "Series fuse rating (A)" is 20 Amps.
Panels have been stored in my bedroom about 2-3 Years now. ::)
They didn't come boxed. Just cardboard on the corners to protect them. I believe they are imported stacked on pallets in bulk.
I stored them back to front on each other to protect the backing (vinyl lining) so two a piece with glass always facing out.
(http://shazam.zapto.org/igal/solar-2/.slide_IMAG0048.jpg)
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OK. I've just found some training video's on the Midnite site.
I had watched a few before but didn't realise the relation between the "Disco" reference and Array Isolation until you used the term in your message.
I see what's going on now.
I was hoping to just run one pair of cables, but I see now that that's not going to happen.
So a "MNPV4" combiner looks the Go? http://www.midnitesolar.com/productPhoto.php?product_ID=393&productCatName=Combiners%20-%20Pre-Wired&productCat_ID=35&sortOrder=3&act=p (http://www.midnitesolar.com/productPhoto.php?product_ID=393&productCatName=Combiners%20-%20Pre-Wired&productCat_ID=35&sortOrder=3&act=p)
With maybe a lightning surge protector as well.
Do I still run a separate breaker between the "Disco" and the "Classic" or not necessary?
Just between the Classic and the battery and another between the battery and the load.
Is the MNPV4 water proof for outside mounting?
And are the connectors at the bottom MC4?
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Quote from: vk4akp on September 12, 2014, 03:44:51 AM
So I can't combine the 4x panels up on the roof under the panels using "Y" cabling?
Is this because the combined current would be too great for any sensible sized cable run?
It's because if one panel shorts out, the combined current from the other three panels could flow (retrograde) through the shorted panel and cause a fire.
Quote from: vk4akp on September 12, 2014, 03:44:51 AM
Then combine into very thick wire (Like on the starter motor of a car) into a main breaker fuse that should be a bit over the combined max current capacity of the panels?
Depends on the length of the cable... use a voltage drop calculator to determine the gauge of the cable.
Quote from: vk4akp on September 12, 2014, 04:15:27 AM
Do I still run a separate breaker between the "Disco" and the "Classic" or not necessary?
Just between the Classic and the battery and another between the battery and the load.
Is the MNPV4 water proof for outside mounting?
And are the connectors at the bottom MC4?
The cable between the combiner and the controller is sized large enough that the power source (your array) can never cause overcurrent. Therefore, for safety no fuse or breaker is needed. However, a disconnect is required and it must be mounted very near the controller. A breaker makes a good switch, and is usually used for a disconenct. Its purpose is to turn on/off the PV input to your controller. That is something you will need to do from time to time.
All Midnite PV combiners are outdoor rated.
Yes, those connectors on the bottom are MC4. Be careful ordering the combiner... the usual configuration with MC4 connectors has high voltage fuses, not 150 volt breakers. Insist that you get one with breakers, not fuses. btw, you can order them prewired.
On the subject of prewired... did you know that you can order a Midnite ePanel (as a kit or prewired) with a Midnite charge controller and an inverter. It includes all breakers, bypass switch, shunt, surge protectors, etc. Just screw it to the wall, connect the PV input, the battery cables, the AC in and out, and the ground cable.
--vtMaps
Hi, Back again. Still sourcing parts.
OK. I ordered a 2P 100Amp DC breaker and it looks quiet good so I'm about to order some more from the same company.
I was going to get another 2x of the 2P 100Amp + 6x 1P 16Amp DC breakers (For the panels).
I couldn't get 15Amp ones and the Panels are supposed to have 20Amp fuses internally so I am hoping 16Amp is close enough? (still a 4Amp buffer) And I know the current could potentially peak past the 16Amps before the breaker finally throws. Hopefully it will still safeguard the Internal Panel 20Amp Fuses. ???
The 100Amp 2 pole breakers I will use them as.
1. Panel main disconnect switch. (After the 4-6x 16Amp ones).
2. Charge Controller to battery disconnect switch.
3. Battery to load disconnect.
Does this all sound good enough?
I can also get 125Amp breakers for the main load disconnect switch but I think pulling 100Amps on the main output is enough.
I'm not even sure yet how thick the wire needs to be to support that current at 12VDC. ??
Comments please?
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Quote from: vk4akp on November 17, 2014, 07:58:40 AM
I can also get 125Amp breakers for the main load disconnect switch but I think pulling 100Amps on the main output is enough.
I'm not even sure yet how thick the wire needs to be to support that current at 12VDC. ??
Hello! I am also new to Pv and I found this thread when digging around on the forum for others with 12V systems. I may be able to answer this question for you!
I have a 2000W Samlex pure sine-wave inverter connected to my 12V battery bank for intermittent use. According to the manual it needs 1/0 AWG wire (8.25mm aka 53.48mm2) to have sustained 200A draw from the batteries. I never run it above 150A so the 1/0 AWG wire I have works just fine with 250A in-line fuses for safety. Also note my cable run is less than 3 feet, which matters a lot.
For 100A from 12VDC, depending how long your cables are, I would suggest 4 AWG (5.19mm aka 21.15mm2) minimum. This would give you about a 2% voltage drop across 5 feet. I try to design all of my stuff for 1% or less loss where possible, but I also have a very small footprint that everything fits in so my cables can be very short. If you can afford it, buy 1/0 AWG. I'm still learning the Pv side of things, and proper battery bank design/management. But one thing I knew going in to this was reducing voltage drop on a 12V system is critical.
This link may come in handy when sizing cables:
http://www.rapidtables.com/calc/wire/voltage-drop-calculator.htm
Just remember to change current type to DC :)
Hope this helps! The M4-ATX 12V PSU is very cool. I may even build a small server box to run off my system as it grows now that I know 12V PSUs exist. I have seen 48V ones in datacenters but never 12V. A lot of what you have been trying to do on this thread is what I am also trying to do since I want to stay with a 12V battery system. Looking forward to reading more about your system!