diy solar

diy solar

Hunting Cabin DIY Solar System

Schuldtp08

New Member
Joined
Mar 27, 2022
Messages
16
Hi All,

In 2021, my family and I built a cabin on our hunting land. While discussing power options, it was decided that we should go off-grid solar as the utility company wanted over 20k to trench a line. I had no experience with solar power systems or really any electrical experience at that time (although I did take some circuits courses in college). While watching some of Will's videos on Youtube and reading through various resources on this forum, I was convinced that I could handle designing and installing my own solar system. I went through and did all the calculations regarding power needs and watt hours desired from the system taking into account what the total price would be. I asked various questions on this forum which involved troubleshooting the PV combiner box wiring, review of the schematic layout, and how the inverter/charger works in regards to the N-G bond. You all delivered and I wanted to share the progress on the install of my system. The install is not finished and I still have several steps to complete, but feel free to give critiques, offer advice, and ask questions.

System Components:
Inverter Charger - MPP Hybrid LV2424
Panels - 8 x 230w 2S4P configuration
Batteries - 3 x 24V 100ah SOK in parallel
PV Combiner Box - Watts247

Panel Specs:

1665509160789.png
Battery Specs:
1665510111627.png

Schematic:

1665509345948.png

I installed the panels on our cabin south facing roof. The angle of the roof is approximately the latitude of the area (42º), which worked out quite perfectly. I obtained some 3" galvanized conduit to run all the wires off local marketplace. The run of PV wires from roof to combiner box is round trip 50ft.

1665509464214.png

The wires exit the galvanized conduit and go through PVC conduit into the cabin. I still have wire clean-up and protection to perform here. I think ill used some sort of flexible tubing/conduit and or zip ties:

1665509784507.png

Here is the in-progress wired set up:

1665509930984.png

I still have yet to complete the inverter to sub panel connections and earthing of the solar portion, but decided to flip the switch on and see if everything was working correctly. I was able to get charging of the batteries in the early day time and a little cloudy. I considered that a success for my first build out.

1665510087173.png

Next steps are removal of the N-G bonding screw inside the inverter/charger, complete grounding/earthing, perform connections to the sub-panel, and build some sort of enclosure for safety of the components and people inside the cabin. Thoughts?

Thank you to this forum and its members for the support of my first solar system.
 
Agree with eggo but you really need an OCPD as close as possible to the batteries. More important than a cutoff switch IMHO.

I don’t see a breaker built into the batteries and three of those in parallel can deliver approximately one crap ton of current.

A class t fuse or a breaker with a high AIC is appropriate here.
 
@sunshine_eggo

The only thing that jumps out is that breaker probably needs to go especially if it's an Amazon special. A cut-off switch is a better idea.

I went ahead an ordered an on/off switch for the system. Thanks. What is the benefit versus using a breaker as an on/off? The installed breaker is Blue Sea Systems 7148 187 Series, 285 Series & Klixon Circuit Breakers, 187 Series, Surface Mount, 150A DC.

@JoeHam

A class t fuse or a breaker with a high AIC is appropriate here.

I have this, but I havent installed yet. I will ensure to install as close to battery as possible. This sufficient?

1665580829598.png

This is what it should look like:
1665583169107.png

I could also throw a bus bar on there to aid in the wire management.
 
@JoeHam

Does the breaker list an AIC rating ?

Here is the breaker specs from blue sea systems website:

1665666721288.png

That was a good read. I really didnt know the difference between the fuse types and what to look for.

@sunshine_eggo

If that's not the plan, make that the plan.

Class T fuse is the plan... and has been ordered. Ill be sure to post an update when I get the other components in!
 
@JoeHam



Here is the breaker specs from blue sea systems website:

View attachment 116190

That was a good read. I really didnt know the difference between the fuse types and what to look for.

@sunshine_eggo



Class T fuse is the plan... and has been ordered. Ill be sure to post an update when I get the other components in!

Blue Sea is a good choice, but you do need higher AIC rating.

"AIC" would be the "Interrupt Capacity" ratings. 3,000A @ 28V applies. AIC rating of Class T fuses is 20,000A.
 
Back
Top