HomeHelpSearchLoginRegister  
 
Latest Threads 
Page Index Toggle Pages: 1
Print
sun 250G almost no output (Read 13572 times)
tiggeroush
YaBB Newbies
*
Offline



Posts: 9
Re: sun 250G almost no output
Reply #12 - Dec 21st, 2012 at 6:12pm
 
where did you order your parts?
Back to top
 
wim3324
YaBB Newbies
*
Offline



Posts: 6
Re: sun 250G almost no output
Reply #11 - Dec 2nd, 2012 at 12:36pm
 
no.it defenitly is one of the mosfets on the output side.you can see that it blowed up.
ordered the mosfets will replace and try again
thanks
Back to top
 
electron
Senior Member
****
Offline



Posts: 340
Re: sun 250G almost no output
Reply #10 - Nov 27th, 2012 at 11:30am
 
Is it possible you have some problems with the AC in your house? Like it fluctuates, or you have a motor on that same circuit (surge) the Hz varies, or maybe you put a surge suppressor on the GTI output?

You will need to open it up and confirm that the pop you heard was really a mosfet and not the cap, check the cap and if it's bulging then that's the problem, which means you put over voltage to it.

Did it smoke too? Smoke is s sure sign of a cap going.
Back to top
« Last Edit: Nov 27th, 2012 at 11:31am by electron »  
wim3324
YaBB Newbies
*
Offline



Posts: 6
Re: sun 250G almost no output
Reply #9 - Nov 27th, 2012 at 11:17am
 
well I measured the short circuit amps it's roundabout 9 amps.,so I decided to connect the panel again to the gti,and the wattage went up to approx 100W then a big bang.
One of the mosfets on the ac side has blown up.
Back to top
 
wim3324
YaBB Newbies
*
Offline



Posts: 6
Re: sun 250G almost no output
Reply #8 - Nov 20th, 2012 at 11:33am
 
electron,
these days I am home after dark,end of the week I will test the panels V and Ioc ,and let you know the results
thanks
Back to top
 
electron
Senior Member
****
Offline



Posts: 340
Re: sun 250G almost no output
Reply #7 - Nov 19th, 2012 at 4:20am
 
You really need to measure the short circuit amps of the panel using a known good meter. You already know the open circuit voltage and they should match the specs on the panel's sticker (within reason).

Do not check it with the GTI connected! You are shorting out the cap inside if you do that, always disconnect the panel first. (you can measure voltage anytime of course).

From what you said it looks like the GTI is doing what it is supposed to do but something else is wrong.

Can you swap out any known good stuff? Do you maybe have another GTI or panel?

It's not recommended by the mfg but I do it all the time, you can connect the GTI to 2 12V batteries in series (24V), car size, and it should ramp up to about 250W and sit there. That's a easy test. Use a known good battery or monitor the voltage when you do that to make sure the batteries are supplying the power you want.

Sometimes when I get too much power on a perfect day I use one of my GTI's to discharge my 24V battery bank so I don't waste any power.

Connect it quickly because it will spark AND AS ALWAYS, TO BE SAFE WITH BATTERIES - make sure you are in a well ventilated area so no battery gases are present!

Back to top
 
wim3324
YaBB Newbies
*
Offline



Posts: 6
Re: sun 250G almost no output
Reply #6 - Nov 18th, 2012 at 12:42pm
 
oke electron,
when I first connect it it "ramps up" to +- 0.3A  +- 40W and stays there.
we are here in the tropics,and have almost the whole day full sun,no shade on the panels,the voltage on the input of the inverter varies between 20V and 23 V.
Back to top
 
electron
Senior Member
****
Offline



Posts: 340
Re: sun 250G almost no output
Reply #5 - Nov 18th, 2012 at 11:20am
 
OK, the MPPT at 20V throws me off because a normal "12V" panel is about 16V MPPT.

Then you should be getting power out of the GTI.

Do you see it ramp up in power when you first connect it? And what does the voltage do during that?

Have you measured the short circuit amps of your panel to make sure that isn't the problem?

Is it nice and sunny? Are there any shadows on the cells? It doesn't take much.

By the way, a good calculation for panel "sticker" wattage vs. what you will see going into the grid is:

panel watts X 0.65 = watts to the grid

So 230W should give you about 149W of power to the grid on a good sunny day.
Back to top
 
wim3324
YaBB Newbies
*
Offline



Posts: 6
Re: sun 250G almost no output
Reply #4 - Nov 18th, 2012 at 11:08am
 
thanks everybody for the input.
the panel is a sovello svl-230 low voltage panel:
Uoc=25.5V !! Umpp=20.4V

using two 10 feet  10AWG cables to connect to the inverter

the inverter is a sun 250 :in the specs it states:DC input voltage range  14V-28V.
?
so now I am really confused.
Back to top
 
electron
Senior Member
****
Offline



Posts: 340
Re: sun 250G almost no output
Reply #3 - Nov 18th, 2012 at 10:06am
 
Solar Freak, glad you mentioned wire, that might be what is keeping his GTI alive!

Lowes has some good prices on 100 ft #10 extension cords. They have 3 wires inside and you can combine two of them together and lower the total resistance of the wire run that way.

Back to top
 
Solar Freak
YaBB Newbies
*
Offline



Posts: 31
Oklahoma
Re: sun 250G almost no output
Reply #2 - Nov 18th, 2012 at 9:59am
 
It should be seeing more than 22 volts at the inverter. So far your lucky on that part because when it gets up higher than 32 volts its going to blow the cap and a fet or two possibly. You probably dont have big enough wire to carry the voltage is why its only 22 volts. Use 10 or 8 gauge Landscape wire on it and your voltage will come way up. You can buy it at Lowes or Homedepot lumber stores Also get a Sun G 600 watt they are made for 24 volt panels. Look at the specs for it too. Get one on ebay it will say the voltage range on the auction page. You want a voltage range DC input from 22V~60V Cheesy
Back to top
 
electron
Senior Member
****
Offline



Posts: 340
Re: sun 250G almost no output
Reply #1 - Nov 18th, 2012 at 9:30am
 
You should immediately disconnect the GTI !!

That's a 24V panel. It's open circuit voltage will be around 40V !!!

Well past the "safe" zone for a 28V max GTI. I've run them to 32V and cringed doing it but you don't want to push 40 into them. The DC side cap isn't rated that high, 35V typically, some of the newer ones use a 65V one but that doesn't mean the rest of the stuff can handle it.

The GTI may be reading 22V at times but it will "let go" of the panel while doing it's MPPT thing and that will cause a over voltage.

I'm not exactly sure why it doesn't see a over voltage when you first hook it up and just shut down. Anything over about 32V shuts down the ones I have.

You have 2 choices, get an GTI made for 24V like the 600W ones, or reconfigure your panel for 12V.

A lot of 24V panels are basically two 12V panels side by side and in the junction box on the back they have jumpers or something and you can reconfigure them for 12V. Just look for the tab wires from the cells on the front and you can trace out how it's all configured, then look at the junction box and see what you have to do to reconfigure it.

You can always put it back if you get a bigger GTI. If you run a higher voltage there is less wire loss (sometimes that may not be worth much).

You might want to think about getting some batteries at some point so you have backup power in case of a power outage.

Welcome to the world of solar power!
Back to top
 
wim3324
YaBB Newbies
*
Offline



Posts: 6
sun 250G almost no output
Nov 18th, 2012 at 5:51am
 
hi ,
starting new for the first time with solar.have a sun 250G grid tie inverter (14-28V)+solar panel sovello 230W Umpp=20,4V.Impp 11.3A)when I connect everything,I get only +- 40 W out of the inverter(128V ,+-0.3A).The voltage on the inverter in side is approx 22.5V)Any advice/help would be appreciated.thank you
Back to top
 
Page Index Toggle Pages: 1
Print