Author Topic: Newbie  (Read 2962 times)

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Sisco

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Newbie
« on: August 27, 2015, 12:47:22 PM »
Hello, need help with type panels I was given, (3) panels are Suniva 285 watt, PMAX-285w, ISC-8.59a, IMP-8.02a, VOC-44.6v, VMP-35.5v.  (1) panel is Jinko, JKM-280P-72, PMAX-280w, ISC-8.81a, IMP-7.89a, VOC-44.5, VMP-35.5v.  Also have flex max fm 80- 150 volt D.C. charge controller.  Would like to know type panels 12v or 24v etc., and if the two will work together.  Goal is to have 3000 watt system to power freezer and  fridge when power is out.  No batteries or inverter yet.  If more info is needed just let me know.  I thank you very much for the help.

dave ames

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Re: Newbie
« Reply #1 on: August 27, 2015, 07:00:07 PM »
Cheers Sisco,

Welcome to the forums. Thanks for providing enough information in your first post for a sensible reply.
Sometimes it can be difficult trying to find out what someone is wanting to do?

Your equipment should play well together...They are all true 24 volt panels, each with 72 cells. We could not
ask for a much better match for different brands of modules.

I would suggest hooking them up as two parallel strings of two modules in series into the outback FM80 and running a 12, 24 or 48 volt system...>
Depending on what kind of deal we can get on an inverter...To help avoid problems it might be best to go with a pure sine wave unit. Even a grid interactive
unit that will do the power changeover for you.

Time to think about how long of a battery backup you might need? In many USA locations we can average 4 full peak solar hours a day (more in summer less in winter.)
So about 4KWH average a day comming in.

Kind Regards, Dave



EDIT: Oops, had the KWH average wrong.
« Last Edit: August 27, 2015, 07:05:09 PM by dave ames »

dnix71

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Re: Newbie
« Reply #2 on: August 27, 2015, 07:34:10 PM »
Those are very well matched panels. If you double them up you will have more than 60v input, so if you do that needs to be done to code to protect yourself (insurance issues) if something goes wrong. If you simply place all 4 panels in parallel at 44voc that is considered low voltage and is legally exempt from code requirements in the US.

Exempt from code doesn't mean exempt from safety though. You still need to size wires and fuses accordingly.

What make/model of fridge are you planning to backup? You will need batteries for this if the fridge is the usual American household upright 120v fridge. You will also need an inverter big enough to >start< the fridge. Starting currents can be 10 times running current, and inverters that large have high idle battery drain. There are workarounds for that.

Frank S

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Re: Newbie
« Reply #3 on: August 27, 2015, 11:41:01 PM »
Not recommending or shrilling for Dimensions  inverters, but my 1800 Pure sine wave has been pulling all of the power in my RV for nearly 3 years now my fridge is a 1990 model Roper 21 cf side by side with water and ice maker even if my wife is brewing coffee as long as the battery voltage is at least 12.6 if the fridge starts up there is never even a flicker on the TV
  I have 10 golf cart batteries and 2 4Ds for my bank with 1100w of PV
 My inverter came out of a retired ST&T service vehicle so no idea of its age
I live so far outside of the box, when I die they will stretch my carcass over the coffin

Sisco

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Re: Newbie
« Reply #4 on: August 28, 2015, 10:09:17 AM »
Thanks for the help,  I think I will stay with low voltage for now.  Batteries, these were what I had planned for before these panels came along.  Interstate GC2-XHD-UTL, have 232 amh 6 volt,  wire 2 ea in series and have 5 banks for a total of 10 batt.  I think this is close to 1065 amp hrs of storage,  figuring is my weak point,  for 3 days.  Fridge-whirlpool-model #WRT3L1SZYWOO, freezer-frigidaire-model#FFFU21M1QWA.  Inverter I was going to use to test with is from a friend , 3000 watt 5000 surge don't know make and brand.  Again thanks to all for the help.

dnix71

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Re: Newbie
« Reply #5 on: August 28, 2015, 06:53:45 PM »
The fridge alone uses about 1.4 kwh a day according to the pdf I downloaded. That's something you have to size for unless you have a generator you can use to boost the batteries if needed.

The batteries will be the expensive part unless you get a gently used set from your local phone company. A 24v setup would be recommended if you want to stay low voltage on your panels and batteries. A 24v inverter pulls a lot less current than a 12. A full size fridge and an upright freezer will pull a lot of power if they happen to be starting or running at the same time.

There are plenty of high power 24v inverters now for a good price. Some of the guys here prefer low frequency inverters for hard start loads like what you have. LF inverters use the batteries instead of caps onboard.

If you can, get a Kill-A-Watt meter and check each fridge/freezer and see what wattage, including the power factor losses, is needed for startup and how much energy each uses in a day. Walmart, Staple and Home Depot sell the P3 Watt meter for cheap.
http://www.homedepot.com/p/P3-International-Kill-A-Watt-EZ-Meter-P4460/202196388  $30 at Home Depot, Wally World sells it for less.

Sisco

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Re: Newbie
« Reply #6 on: August 29, 2015, 10:42:03 AM »
Thanks dnix,  I have a generator to top off as needed.  Also need to learn more about MPPT.  I will get a kil-a-watt meter and check what I have for usage in a day.  For now going to step back and do some more planning, and see which way I want to go.  Cost will play the most important part.  My head has to much sunlight pouring, think my brain is getting sunburn.

Gitrmstr

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Re: Newbie
« Reply #7 on: September 10, 2015, 07:02:31 PM »
Posted in the wrong thread, my apologies! Good luck with your project