Off Grid Breakers and Fuses

[LiquidFirefly]

Hello everyone. Wishing everyone an awesome weekend. Needing some help, I'm sort of stuck. I'm a newbie to solar. I'm planning on starting with this tiny off grid system and expanding it. I was wondering if someone could help me by posting a wiring diagram for my system.

This is the set up I have so far please correct any mistakes. 12 V off grid system will be wired in parallel. I'm starting with two possibly four 100W solar panels. I will be using MP4 connectors with 10 AWG wire. With one 60 amp fuse on each string. 6 wag wire. A 60 amp PWM charge controller, Wire , a 60 amp fuse, then two 12 V, 109 amp hour batteries connected in parallel to the inverter with 0/1 AWG. 175 amp breaker or Fuse, a (12v) 1500 W pure sine wave inverter with grounding wire (unsure of size) to earth ground, and GFCI Power strip plugged into the inverter.

Eventually the system will grow to twelve 100 W solar panels, MPPT charge controller, and a battery bank of fourteen 109 amp hour batteries. Please let me know if the wire sizes, charge controller amperage, or breaker/fuse amperages must change. Thank you.

[Mike90250]

stop before you spend another nickle. If you are going to grow the system beyond 300W, 12V panels are not the efficient way to go. 250W 30V panels are made by the bazillions. and much less expensive than the 12V panels per watt.
What are your loads ? if your loads are above 1,000w, or if you are needing to parallel batteries to gain enough storage capacity, you need to go up to a higher voltage and leave the 12V toy system behind

[LiquidFirefly]

Thank you for your response. Maybe you were getting a better deal for the 250 Watt panels. I haven't found much of a difference in price. Perhaps I will close out my current system with two panels and four batteries, so I can have some power for now. Then I can do your 250 W system as a separate project.

I thought I needed a 3000 W system. I assume by loads you are asking what I am running. I will be running some water pumps, window AC unit, box fans, small refrigerator, 3 -5 compact florescence bulbs, a countertop icemaker, small washing machine, countertop dishwasher, A heavy duty vita mix blender, desktop computer, TV (50 inch LCD) and DVD player, refrigerator, small deep-freeze. I will be running everything on AC. I have no DC appliances.

The computer is on pretty much all day, the AC will get a workout, fans will be on a lot, I don't watch much TV, and I use daylight during the day.

[LiquidFirefly]

If you think I need less power that's a good thing. Like I said I'm really new to this and I didn't even want to wire my system in parallel. I was afraid to mess with too much current. If you have an example or wiring diagram for a 250 W system I can use it to build my 250w system. I just get confused when it comes to the fuses and breakers mostly but sometimes the wire sizes. I thought that AWG wires sizes could be interchanged with SAE wire sizes but although the numbers are the same they look totally different. I prefer to use all breakers instead of fuses if that is possible. Thank you so much for your help.

[Mike90250]

Midnight Solar has a great selection of DC breakers and enclosures for them.

More than 2 batteries in parallel leads to un-equal current sharing and can quickly kill the battery bank when one battery goes weak.

12V systems carry MORE amps than a 24V system. 12V @ 300W = 25A and fat wire$. 24V @ 300W = 12.5A

I thought I needed a 3000 W system.

Then for that size system you should be running 48V to keep the AMPS managable
3000w @ 48V is only 63A @12V = 250A That is dangerous amounts of amps, that will melt wires inside the inverter, because they "never expect someone to use that much"

With fridge, and all your other appliances, you may not have "Large" loads, but several small ones over long term, requires large batteries, and series batteries are preferable to parallel batteries.

[LiquidFirefly]

OK I think I am very confused. I thought the entire system had to be wired the same way. I thought if your panels were wired in parallel your batteries had to be wired in parallel also. Will you post a diagram of a properly wired 1000 W off grid system including battery wiring and fuses or breakers? Thank you so much.

[SunEagle]

Hello everyone. Wishing everyone an awesome weekend. Needing some help, I'm sort of stuck. I'm a newbie to solar. I'm planning on starting with this tiny off grid system and expanding it. I was wondering if someone could help me by posting a wiring diagram for my system.

This is the set up I have so far please correct any mistakes. 12 V off grid system will be wired in parallel. I'm starting with two possibly four 100W solar panels. I will be using MP4 connectors with 10 AWG wire. With one 60 amp fuse on each string. 6 wag wire. A 60 amp PWM charge controller, Wire , a 60 amp fuse, then two 12 V, 109 amp hour batteries connected in parallel to the inverter with 0/1 AWG. 175 amp breaker or Fuse, a (12v) 1500 W pure sine wave inverter with grounding wire (unsure of size) to earth ground, and GFCI Power strip plugged into the inverter.

Eventually the system will grow to twelve 100 W solar panels, MPPT charge controller, and a battery bank of fourteen 109 amp hour batteries. Please let me know if the wire sizes, charge controller amperage, or breaker/fuse amperages must change. Thank you.

A very big misconception with a lot of people is that you can grow an off grid system. Whatever you start with a 12volt system hardware will be pretty much impossible to use if you go past 1000watts.

1.Going with 12v panels is much more expensive then with grid tie panels (200watt and bigger) and a lot of small wattage panels require larger wire and fuses to protect it.
2. Also every one of your batteries will be not be compatible with any new ones so they all get tossed out.
3. Unless you start out with a quality MPPT high amp rated charge controller then your first one will be useless because it won't be able to accept a lot of panel wattage or deliver the charging amps needed.
4. And finally starting out with a small inverter will be useless once you need more and starting out with a large inverter connected to a small battery system can kill those batteries due to the inefficiency of a large wattage inverter.

[LiquidFirefly]

OK thank you so much for your response. It seems to be getting more and more confusing. To save a lot of trouble can you just post a wiring diagram for a 1,000 watt system? Please include the proper wire gauge sizes, breaker amperage , and charge controller amperage. Please show the complete system including where to put fuses and the grounding wire. It would be nice if I could use my 12 V 1500 W inverter and I will use 200 to 250 watt panels. There is no electricity in this spot so this is an off grid system. Since I seem to be confused about the battery bank will you include the battery bank wiring in the diagram as well?
Thank you

I will purchase and input the correct equipment, I just need an example of how it is done properly.

[Mike90250]

Attached is a plan from my drafts To get the wire sizes, you use a wire gauge that is safe/rated for the breaker used on the wire. You could go larger, depending on the distance involved
powerplan-4_LMR.png

[LiquidFirefly]

Wow! You are so awesome. THANKS!!!

[Mike90250]

Attached is a plan from my drafts To get the wire sizes, you use a wire gauge that is safe/rated for the breaker used on the wire. You could go larger, depending on the distance involved