# What is wrong with my system?

10 Posts
Jan 28, 2009 03:04 pm
What is wrong with my system?

I have succeeded to up running a 1000watts non-glass type panel system at home and something happen on the second day.  After night usage (only a TV and a light in my living room, total about 100w uses until 12am) from 3 batteries (12V 33AH in parallel), the inverter (Sochet GS-2500) must turn off on morning for 30 minutes. Otherwise, the inverter only draws the power from batteries and not received any power from panels. I have to turn-off inverter for 30 minutes each morning to allowed the panels taking in place. This happen wasn’t on the first day when I up running the system; it was observer on second day and so on. Is wire problem, or weather temperature cause it? I am living at san francisco bay area, california.

351 Posts
Jan 28, 2009 04:18 pm
Re: What is wrong with my system?

The first question is, how long are you running the light and TV ?
You said until midnight, but you didn’t say when you are turning them on.

My initial guess is that you are drawing the battery down too far and experiencing a low voltage shut off sometime during the night.

If you are leaving the draw switch on, the inverter puts about .6 amps load (about 7 watts) on the battery. Turning that switch off will reduce the load to less than 2 milliamps.

Disconnecting the inverter could allow the voltage to recover to above the low voltage disconnect limit, and would reset the inverter.

What type of solar charge controller are you using ?

You may also be estimating your load a little on the low side.  What make/model of TV do you have and how many watts is that light ?

Jan 28, 2009 08:16 pm
Re: What is wrong with my system?

33 amphours at 12 vdc.
100 watt load.
100 / 12 = 8
33 / 8 = A completely dead battery in a little less than 4 hours. Typically, one wants to size a battery bank so that the night time load(s) draw only the top 20% of full charge. No more that 50%.

1000 watts of PV at 12 vdc nominal.
4 hours of equivalent full rated charge.
1000 / 12 =  less than 83 amps (I'd say more like 50 amps)
4 x 50 = wasted potential on 33 amphour batteries.

Try a battery bank bigger than 33 amphours. At least 440 amp hours at the 20 hour rate. Ideally, 1000.

« Last Edit: Jan 28, 2009 08:31 pm by Thomas Allen Schmidt »

578 Posts
Jan 29, 2009 01:16 pm
Re: What is wrong with my system?

hello,

I think I saw the photos that were just posted on the forum.
beyond the functionality of the system, I have some serious safety concerns that i think should be addressed.

1.  the terminal blocks on the wood under the modules are not acceptable.  pv is live in sunlight and although there is a wood block in between, that wiring is not safe for outdoors.  I would strongly recommend a combiner box for putting modules in parallel.  each series string should have its own series circuit breaker or fuse.  if you have all 8 in parallel then you would likely have 8 15a din rail circuit breakers mounted in a box something like this.

http://store.altenergystore.com/Enclosures-Electrical-and-Safety/Electrical-Enclosures/Combiner-Boxes/Outback-FLEXware-PV8-Combiner-Box/p6693/

this box would typically be mounted outside right by the modules. all pv wires would go in, negatives tie on the bussbar and positives each go through a breaker. then you would leave with 1 positive (ideally red) 1 negative (ideally white) and one equipment grounding conductor (ideally green) from that enclosure.  you would roughly likely have 64a at 12vdc so at least 6awg would be required.  you should be able to source that in colors locally at home depot.

2.  regarding the power center setup.  i see a square d disconnect but i cant make out the unit.  being that you have more than 60a rated dc power at 12v, i think that it is incapable of breaking that cirucit.  from the tristar i dont see wires going to the battery bank.  the tristar battery output must go to the battery terminals or busbars pulled from the battery terminals.  the output of the charge controller must not be connected directly to the inverter.

3.  battery to inverter cables should be connected to the battery terminals with appropriate lugs.  the alligator clips should not be used in permanent installations as if they are bumped they have the ability to create dangerous sparks and arcs.  if a common busbar is needed to tie the battery to the inverter, an enclosure like this is generally used.  this will enable you to use battery cables with 3/8 lugs (if the inverter can accept them) that will make safer connections and allow for an appropriate disconnect.

4.  the battery and cables from it especailly are too small for the inverter.  for a 2500 w inverter at 12v size 4/0 would be appropriate.  find a deep cycle battery with threaded posts on it or even two golf cart batteries from wal-mart and use 4/0 cables with to connect batteries to each other and batteries to inverter (or dc disconnect center).

http://store.altenergystore.com/Enclosures-Electrical-and-Safety/Electrical-Enclosures/DisconnectLoad-Enclosures/Dc/Midnite-Solar-MNDC250-Mini-250-Amp-DC-Disconnect/p2416/

or

http://store.altenergystore.com/Enclosures-Electrical-and-Safety/Electrical-Enclosures/DisconnectLoad-Enclosures/Dc/Outback-FlexWare-FW500-DC-breaker-enclosure/p5576/

before addressing functionality, i am very worried for safety and fire hazards.  good luck in the process, and please feel free to ask more questions, the forum folks would be glad to help.

james
altE staff

AltE
"Making Renewable Do-able"
http://www.altEstore.com/

Tel: 877.878.4060 x107  or +1.978.562.5858 x107
Fax: 877.242.6718  or +1.978.562.5854

10 Posts
Jan 29, 2009 02:14 pm
Re: What is wrong with my system?

36" Admiral TV 150W, TopLite lamp 20W, TriStar solar controller TS-60, Socket GS-2500 inverter. Tree 12V 33AH batteries in parallel. The problem is, if inverter runs over night, then the controller shows no solar power received on next sunny morning, the inverter continue drawing power from those batteries only. But, if I turn-off the inverter for 30 minutes and back-on, everything will be OK, the controller shows solar panels generate power to whole system.

10 Posts
Jan 29, 2009 02:20 pm
Re: What is wrong with my system?

I 've three 12v 33AH batteries in parallel right now, TV and light use battery power only after 5:30pm until 12:00am.

10 Posts
Jan 29, 2009 02:31 pm
Re: What is wrong with my system?

Thanks James, I will take your advise for safety issue. I will receive more panels next month from SBM solar, then I will re-do all wires and control set. There a lot of people were interesting this project, and I just try to show them that was easy, simple and cheap as well.

220 Posts
Jan 29, 2009 03:29 pm
Re: What is wrong with my system?

hi gary,

good advice on beefing up on that wiring and battery bank. me thinks that's gonna help alot.

"simple and cheap as well."

i agree that this can be "simple" but cheap? i guess that is relative. someone without company connections might expect to pay about five grand for a 1kw array of pv. for me that ain't cheap. i was thinking prices might start to come down a little by now. where are the \$1/watt modules we all were promised? maybe next year..

cheers and good luck, dave

Jan 30, 2009 02:41 pm
Re: What is wrong with my system?

A picture can speak a thousand words.
To answer your question with more accuracy now that I have seen it Mr. Cheung.
If its in the U.S.A., its illeagle.
If a U.S. Fire Marshall were to see it he would probably slap a big fine on you and make you disassemble it.
Sounds harsh I know but if it were to burn your home down and that damaged your neighbors homes, how to you suppose you and your neighbors would feel about it then?
http://www.nfpa.org/
Heres a picture for you to look at Mr. Cheung.
http://www.precisionpower.biz/images/fire.jpg
I applaud your desires for using PV Mr. Cheung and that you know that you need to upgrade the safety of your system but in the meantime I suggest you add some fire extinguishers.
Other than that. I've got nothing else to say.

26 Posts
Jan 31, 2009 04:07 am
Re: What is wrong with my system?

Gary;Here is some good reading

"Photovoltaic power systems and the 2005 National electrical code suggested practices"

Tried to create a link for you but I cannot. A search should find it ok.It is in PDF format.
The AltE site has some cabin package systems that have a wiring diagram also.A wire size chart is suggested too.

It does look dangerous.You really do not want to leave terminals where anybody can get to them (or animals)Those + - rails exposed no good.As mentioned a combiner box is missing,then you should go to a DC disconnect box with a ground fault.Grounding procedures should be looked at too.

Good thing you asked these guy`s, best of luck to you.

26 Posts
Jan 31, 2009 04:19 am
Re: What is wrong with my system?

http://www.nmsu.edu/~tdi/Photovoltaics/Codes-Stds/PVnecSugPract.html

Heres a link to info..

10 Posts
Jan 31, 2009 04:31 pm
Re: What is wrong with my system?

Gary;Here is some good reading

"Photovoltaic power systems and the 2005 National electrical code suggested practices"

Tried to create a link for you but I cannot. A search should find it ok.It is in PDF format.
The AltE site has some cabin package systems that have a wiring diagram also.A wire size chart is suggested too.

It does look dangerous.You really do not want to leave terminals where anybody can get to them (or animals)Those + - rails exposed no good.As mentioned a combiner box is missing,then you should go to a DC disconnect box with a ground fault.Grounding procedures should be looked at too.

Good thing you asked these guy`s, best of luck to you.

Thanks Robert.

10 Posts
Jan 31, 2009 04:32 pm
Re: What is wrong with my system?

Thanks, I've download it now.

Disclaimer and Disclosure

The Alternative Energy Store, Inc reserves the right, within its sole discretion, to refuse or delete any posting or portion thereof, or terminate or block the access to this forum.

The opinions and statements posted on this forum are the opinions and statements of the person posting same, and do not constitute the opinion or act of the Alternative Energy Store, Inc (AltE). The Alternative Energy Store, Inc does not endorse or subscribe to any particular posting. No posting shall be construed as the act or opinion of the Alternative Energy Store, Inc.

## Share

Click on an icon to share! If you don't see the method you want, hover over the orange "+".

## Feedback

What can we do to help you?

Please enter a summary
Sorry, the copyright must be in the template.
Please notify this forum's administrator that this site is using an ILLEGAL copy of SMF!
Copyright removed!!