Solar setup

kau

I would like to explain my current setup,the changes to be made and my questions.
 Okay I have 1- 245 watt panel 8' of 10 awg "solar wire"to a c35 Schneider Pwm cc, 12awg romex @ 6' to 4 12 volt deep cycle batts wired in parallel, 14/3awg romex all 4 wires joined for the pos side going back to a 600 watt sine wave inverter, then 12/2awg romex with all 3wires joined from the neg on the batts to the neg on the inverter, I have no fuses in place the inverter is grounded with a single 10awg coper wire.Okay well once again I can't edit my post, does any one else have this prob! Argg, maybe this site does not like iPads. So I am going to replace the Pwm with a midnite solar kid 30. Questions what size wire should I be using and what size fuses and where should I place them? The lengths will be the same. Also using romex the way I am, is that lame, I know when you use 12/2, 14/3 or similar size romex as a single wire the awg is increased greatly(not sure how much), just would like a different ( more experienced) opinion. I am not to poor to buy the proper wire just like to save money anyway I can.

mvas

1) A fuse / CB on the (+) terminal of each battery rated 15 amp or 20 amp
2) A fuse / CB in the (+) cable between the Solar Panel and Charge Controller rated 1.5 x Isc
3) Does the Inverter have built-in fuse or CB for DC input ?

Make sure your parallel connected batteries have equal length wires.

petertearai

and fuse each paralell string 

Estragon

Fuses and breakers (OCD) are sized to protect the wire so the wire doesn't become the fuse (overheat and cause a fire). First you figure out the wire needed for the load, then choose a breaker to protect it.

That said, using heavier wire than strictly necessary helps efficiency. Also, in your case heavy cable connecting your parallel bank of batteries will help keep it balanced.

Personally, I would leave the 10ga panel to CC and install a 15a breaker as a dual OCD and disconnect. For CC to battery I would use the biggest wire the controller will take. For batteries use the biggest cable you can find (eg 2/0) with equal lengths going to a common connection (ideally a heavy buss bar), with 20a fuses on each positive wire. From the common connects I would use the biggest wire the inverter takes with a breaker sized accordingly (inverter maker probably specs this).

Using romex the way you are is kind of lame. Not having proper OCD protecting wires is downright dangerous. If you were going long distances it might be worth looking at ways to minimize wire costs, but with your shorter runs it's penny wise and pound foolish IMHO.

PNjunction

What are your 4 / 12v deep cycle batts?  Make/model/chemistry (flooded - agm)?  New / used?

We often warn about so-called deep cycle batteries which truly aren't - common in the 12v arena.  You *can* get by if they aren't truly deep cycle (but labeled as such), but only if you know the ropes up front - otherwise you'll be buying new batts sooner than later....

kau

mvas said:

1) A fuse / CB on the (+) terminal of each battery rated 15 amp or 20 amp
2) A fuse / CB in the (+) cable between the Solar Panel and Charge Controller rated 1.5 x Isc
3) Does the Inverter have built-in fuse or CB for DC input ?

Make sure your parallel connected batteries have equal length wires.

okay so a 20amp fuse on pos side for each batt
2) a fuse rated 1.5 x Isc ? Don't comprehend that
3)don't know if the inverter has a built in fuse I will ask windnsun
 will check the wire lengths

Estragon

Re 2)
Isc is the short circuit current rating in amps for your panel.