Beginner installation

[cabinonthehill]

Hi everyone, I'd like to introduce my self. My name is Ian, and I'm a carpenter living in Ontario, Canada. I'm in the process of building a small cabin on an 80 acre wood lot in central Ontario.

The cabin shell is all done, and this spring I'll be resuming the project and completing the interior. Last fall I started wiring a cabin with the intention of setting up a very small and simple solar system this spring.

This is what I've done so far: I have wired two separate 'circuits', one for receptacles, the other for lights. The circuit with receptacles includes two GFCI's on the main floor, and one GFCI in the loft. The other circuit includes one ceiling light fixture on the main floor with single switch, and two pot lights in the loft with single switch. All lights are LED. Everything is wired with 14/2 Romex.

The circuits are wired with a three prong male plug on the end. The idea here is that I can plug these circuits into an inverter. I tested the system by plugging the circuits into an extension cord coming from my portable Yamaha generator. The lights and GFCI plugs worked fine.

I realize that this is not a conventional setup. I'm not necessarily looking to be up to code or conventional. I just want to know if this setup will work and not burn the building down or electrocute someone.

This is what leads me to my first question:

1.A. Will this work with an inverter, just as it did with the generator?
1.B. Is this setup safe as it is, or does it require something additional, such as grounding?
1.C. If grounding is required, could I end the circuits in a junction box and run a ground wire from the box to a grounding rod outside? Would this work in grounding the circuits, and is it necessary seeing as the GFCI outlets would mitigate the need for grounding in the first place?

The solar setup that I am planning is as follows:

Renogy 100 watts 12 volt panel
30' 10 AWG wiring from solar panel to CC
Mohoo 20A PWM CC
Eaton 140Ah 12 volt AGM battery
Renogy pure sine wave off grid battery inverter 500W 12 volt

This setup is sized to charge cellphones and run the three lights in the cabin at night. The system will be used about every other weekend, two to three days at a time. Appliances run off of propane, anything that requires more power I'll run off of my generator.

This leads me to my second question:

2.A. Do I need to ground this small solar setup, and if so, what would this entail? Ground the solar panel, inverter and battery?
2.B. Do I need to use fuses between the panel and the CC, as well as between the battery and the CC and the battery and the inverter?

Thank you for taking the time to read through this. I'm grateful for any and all help. If this isn't going to work I don't mind going back to square one, but would appreciate being pointed in the right direction.

Cheers,

Ian

[emartin00]

Well to start, I would wire both circuits into a small circuit breaker panel. Then your incoming power to the panel can be wired to the inverter. All circuits should have some form of over current protection (fuse or circuit breaker) regardless of power source.

[SunEagle]

My first question back to you is what do you estimate your daily watt hour use will be for those lights and any loads you plug into the receptacles?

Based on that 140Ah 12v battery you can safely get (140Ah x 12V x 25% = 420watt hours). Which is not much but may be enough for your needs.

A short coming of that system is you really need about 14 amps of charging and a single 100 watt panel will not get you that. To keep that battery happy you really need 3 of those 100 watt if their Imp ~ 5.5 amps each.

Also while the renogy pure sine wave inverter are ok there really isn't any good way to wire it to multiple light circuits and receptacles. They were designed to plug the load directly into it outlet or us an extension cord (minimum of a #14/3) to your loads.

There may be a way to connect all of your loads to a single breaker panel and then wire a heavy duty cord that is hard wired to the panel bus on one end but plugs into the inverter at the other. This is not necessarily safe but for "temporary use" it will work.

All equipment (panel frames, CC, inverter) need to be connected to ground. You could also connect the negative terminal on the battery to ground or you could let it "float" as long as you have a fuse on it protecting the negative cable. You also need to fuse the positive battery wire.

If you go with more that 2 panels you will need to fuse each using a combiner box that will be connected to the CC.

[citabria]

Ian,
I live (off-grid) because grid power is not available. I am on an 80 acre homestead surrounded by National Forest.
Please, Please read some, if not all of the stickies on this page: https://www.solarpaneltalk.com/forum...-panel-systems

I think the hardware that you listed is not going to work for you. You need to calculate some numbers, daily/nightly loads, battery capacity required, panel production, etc.
There are youtube videos that step you through the processes.

I think you need to save your money and design a 24 volt or a 48 volt system. Get away from 12-volts.

I know there will be several opinions, but you want to save money and not burn through money on a piece of crap.....

This homestead power setup started with the generator, then the batteries for night time, then the solar panels came about 7 or 8 years later. In December I can get up to 5.5 hours of insolation for the solar panels, so it made sense to upgrade to the panels. Your location...Not so much.

[cabinonthehill]

Thank you for the replies everyone, very much appreciated.

emartin00 and SunEagle, you mention wiring the circuits into a breaker panel. Do you have any recommendations on what type of breaker panel to use? Can I use a small residential sub panel and wire the circuits to standard 15amp breakers? Or can I do something simpler such as routing the wires into a metal box and protect each circuit with an appropriately sized fuse and ground the box to a ground rod outside?

SunEagle, can you recommend any 12 volt pure sine wave inverters that can be hard wired into a circuit breaker panel that are in the 300-600 watt range? Do these even exist at such low wattage?

To answer the questions about load, the two pot lights I have in the loft are rated at 4 watts (8 watts combined), and on the main floor I have an 8 watt ceiling bulb. This is equal to 16 watts. I will also be periodically charging a couple of cell phones. We're outside all day, and generally don't plan to go to the cabin in the dead of winter or when there is heavy rain in the forecast. We will be using the lights in the evening. Assuming worst case scenario we use the lights for 8 hours a day, and charge two cellphones for 4 hours a day, 6 watts each, we'd be looking at 176 watts per day. I don't ever plan to draw more than this from the panels as this is a recreational cabin where we go to enjoy the outdoors. We're not sitting inside watching movies and browsing the web. We essentially sleep and prepare food in the cabin. We use propane appliances. We also never spend more than 3 consecutive days at the cabin.

SunEagle, you mentioned that the 100 watt panel would not be enough to keep the 140Ah batter happy. Assuming the above stated load of 176 watts per day, a single 100 watt panel should produce enough power to keep the battery charged? Worst case scenario in the winter, my area gets an average of two hours of insolation per day, the panel may only produce 11 amps (5.5 amps x 2), though likely even less in a real world setting. So likely to be safe, I would need at least two 100 watt panels?

As for grounding the solar setup, can I run the bare ground wire from the solar panel(s) through the walls in the building rather than running it down the outside? I'm asking simply because I don't like seeing wires and conduit running along the outside of the building. The walls of the cabin are open on the inside so running wires out of sight is currently very easy.

Citabria, thank you for your input about running a 24 volts system rather than 12 volt. The cabin is 200 square feet, very small. We spend very little time inside. We also use the cabin for weekends only, about 2 weekends per month from May to October. It's really just a jumping point to enjoying the outdoors. Knowing that our load is going to be about 200 watts per day, would you still recommend 24 volts?

Thanks again for all the help!

[Bala]

If you are you going to run only some lights and charge some phones then you dont need the Inverter and A/C system.

Run 12V DC lights and phone chargers.

As the Inverter uses power it will save you power and as long as you put in a fuse at the battery it will be totally safe,

Run another set of cables for DC, seperate to the AC ones you have already put in, leave the AC wiring as you may want to expand and some point and may use it then.

But for now you only need DC.