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Hi all,
I am new to solar but a thorough researcher (usually). I am not asking to be spoon fed but I am close to completing a small DC only (no inverter) off grid system and would like to run it past the folks who have the experience I dont before I finish the system off and plug it all in so here I am. This is a hobby/learning project and has been a fun ride up the learning curve so far. Forums like this one have sure made it easier so thank you already.
Primarily I am planning to power 24v aquarium lights (inside the house) which use under 0.5kWh each day (70w at peak) and a small 1a @ 6v rated pond pump. I will probably add a few usb ports in future too for charging phones etc, but we will see how it goes. The load is all adaptable (eg I can turn lights up and down and change the time of day they come on and off) and I wouldnt even mind if the lights turned off on an overcast week etc. I could say I planned it to be more natural haha. I have just purchased 2 relatively cheap 12v 75ah agm batteries to get me started and I already have a MPPT 40a (charge) 20a (load) controller with 2x200w panels (17.5v each wired in series). I realise the packs will only give me about 20ah of power at full charge (roughly what id need over a 24h period for just the lights and pond pump) but plan to adapt when the lights come on/turn off to suit. The controller also has a setting that apparently runs the load from the panels and switches to battery when the panels are insufficient so Ill be able to have a play with that if needed too. I also have a bluetooth monitor/app for the controller so I can get a better idea of what I need to change as I go.
The above, as you can tell, is all what I might be able to call educated ifs and buts haha but thats the fun of it. The reason I am writing this post is to ensure I am doing it all safely. I thought writing my intended uses might help. I will write below a summary of what I am doing to wire it all and if anyone sees anything that raises an eyebrow or has any advice/dos and donts, I would be very appreciative if you could let me know.
The bulk of the system will be going in a small garden shed in what is basically a small but solid wooden box/bookshelf as I am renting and would like it to be easily removable. My panels will be in the backyard and touchable. Therefore, I plan to ground them. I have dialled b4 I dug and installed a grounding rod already. I am now waiting on a clamp on multimeter to make sure its resistance is under the 5ohm people seem to recommend and have a secondary place ready should I need to install a second rod. The chassis of my charge controller will also be connected to the grounding rod. I am using 10awg (approx 5.2mm2) and smaller throughout the system except for the grounding wire which is slightly larger at 6mm2.
I have 3 30a circuit breakers and plan to use one on the PV positive at the panels (although since purchasing and reading more Im pretty sure this isnt really necessary?). The other 2 will be installed right next to the batteries, one on the positive & one on the negative leading to the charge controller. The load will be run directly from the charge controller and even though it has inbuilt overload protection, I am using a 15a breaker on the positive at the controller which will also act as a distribution block of sorts. From the 15a breaker I will have one wire going to a buck converter then a 2-3a fuse and likely 16-18awg going to the pond pump and a second 12awg wire that will make the 5-6m run into the house. I have chosen 12awg as it fits through holes at the bottom of my windows conveniently right next to the aquariums and should be more than enough to handle my load with little voltage drop. Inside the 12awg will hit a 4-way fuse block where it will be appropriately fused depending on what size wire I use to get to the aquarium light controller and whatever voltage converter(s) I end up using for charging phones etc etc.
And that is where I am at for now. Sorry for the essay but as I am renting and have 2 children under 6yrs so I want to be sure I have not overlooked anything critical and that I have absorbed the weeks and weeks of reading safety posts well.
Other than that, I only really have 1 question for you all. What do you think about putting 150a connecters (XT150) on each of the grounding wires? This would mean I can easily move the panels undercover should there be word of incoming hail/wind and that I can easily move the charge control/battery box inside for modifications etc.
Thanks for reading if you made it to here, and for any advice in advance.
I am new to solar but a thorough researcher (usually). I am not asking to be spoon fed but I am close to completing a small DC only (no inverter) off grid system and would like to run it past the folks who have the experience I dont before I finish the system off and plug it all in so here I am. This is a hobby/learning project and has been a fun ride up the learning curve so far. Forums like this one have sure made it easier so thank you already.
Primarily I am planning to power 24v aquarium lights (inside the house) which use under 0.5kWh each day (70w at peak) and a small 1a @ 6v rated pond pump. I will probably add a few usb ports in future too for charging phones etc, but we will see how it goes. The load is all adaptable (eg I can turn lights up and down and change the time of day they come on and off) and I wouldnt even mind if the lights turned off on an overcast week etc. I could say I planned it to be more natural haha. I have just purchased 2 relatively cheap 12v 75ah agm batteries to get me started and I already have a MPPT 40a (charge) 20a (load) controller with 2x200w panels (17.5v each wired in series). I realise the packs will only give me about 20ah of power at full charge (roughly what id need over a 24h period for just the lights and pond pump) but plan to adapt when the lights come on/turn off to suit. The controller also has a setting that apparently runs the load from the panels and switches to battery when the panels are insufficient so Ill be able to have a play with that if needed too. I also have a bluetooth monitor/app for the controller so I can get a better idea of what I need to change as I go.
The above, as you can tell, is all what I might be able to call educated ifs and buts haha but thats the fun of it. The reason I am writing this post is to ensure I am doing it all safely. I thought writing my intended uses might help. I will write below a summary of what I am doing to wire it all and if anyone sees anything that raises an eyebrow or has any advice/dos and donts, I would be very appreciative if you could let me know.
The bulk of the system will be going in a small garden shed in what is basically a small but solid wooden box/bookshelf as I am renting and would like it to be easily removable. My panels will be in the backyard and touchable. Therefore, I plan to ground them. I have dialled b4 I dug and installed a grounding rod already. I am now waiting on a clamp on multimeter to make sure its resistance is under the 5ohm people seem to recommend and have a secondary place ready should I need to install a second rod. The chassis of my charge controller will also be connected to the grounding rod. I am using 10awg (approx 5.2mm2) and smaller throughout the system except for the grounding wire which is slightly larger at 6mm2.
I have 3 30a circuit breakers and plan to use one on the PV positive at the panels (although since purchasing and reading more Im pretty sure this isnt really necessary?). The other 2 will be installed right next to the batteries, one on the positive & one on the negative leading to the charge controller. The load will be run directly from the charge controller and even though it has inbuilt overload protection, I am using a 15a breaker on the positive at the controller which will also act as a distribution block of sorts. From the 15a breaker I will have one wire going to a buck converter then a 2-3a fuse and likely 16-18awg going to the pond pump and a second 12awg wire that will make the 5-6m run into the house. I have chosen 12awg as it fits through holes at the bottom of my windows conveniently right next to the aquariums and should be more than enough to handle my load with little voltage drop. Inside the 12awg will hit a 4-way fuse block where it will be appropriately fused depending on what size wire I use to get to the aquarium light controller and whatever voltage converter(s) I end up using for charging phones etc etc.
And that is where I am at for now. Sorry for the essay but as I am renting and have 2 children under 6yrs so I want to be sure I have not overlooked anything critical and that I have absorbed the weeks and weeks of reading safety posts well.
Other than that, I only really have 1 question for you all. What do you think about putting 150a connecters (XT150) on each of the grounding wires? This would mean I can easily move the panels undercover should there be word of incoming hail/wind and that I can easily move the charge control/battery box inside for modifications etc.
Thanks for reading if you made it to here, and for any advice in advance.
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