Off Grid System - 1st timer - Advice / checking for correct setup

[chrisski]

I was told that the 24V Victron Inverter has a built in 100A Fuse thats not replaceable and so was told to place my 100A fuse in line between the batteries and inverter as close to the battery as possible, but I guess 4 AWG wire is not rated for 100Amps so you are correct and I am glad I see this now, would have had a nice fire hazard sitting around.

24 volts. I missed that. 4 AWG, with the correct insulation will suffice. By my chart that is 75°C. I like getting 60° C insulation, so 2 AWG. 3 AWG will work but is hard to find.

[PySoMaNiC]

I was told that the 24V Victron Inverter has a built in 100A Fuse thats not replaceable and so was told to place my 100A fuse in line between the batteries and inverter as close to the battery as possible, but I guess 4 AWG wire is not rated for 100Amps so you are correct and I am glad I see this now, would have had a nice fire hazard sitting around.

[chrisski]

I’d determine wire based off ampacity. I expect 150 amps max from the inverter. I’d use 1 AWG with the inverter and battery.

150 amps is an uneducated guess. The actual math is:

inverter watts x low voltage cutoff / inverter efficiency / x 1.15 for surge = expected amps with safety factor

Whatever the formula says is also the fuse size.

not everyone used the 10 volt inverter cutoff, but amps skyrocket as volts drop to keep the same. You’ll find other formulas that will justify smaller wire. 4 AWG wire will work, but needs to have the correct insulation rating. Because of voltage loss and it getting hot, I would not use it.

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[PySoMaNiC]

Hey,

First off thank you for looking at my post. My main purpose for this setup is to power my freezer which is going to be converted into a fridge, even as a freezer it consumes 197KwH a year, I plan to charge my devices including rechargeable LED lights during daylight hours when my solar panels are producing more then I am consuming. Anyways my worry is not the amount of capacity I have as I would just add more batteries to my setup should that be a problem.

I am more concerned about the system setup, making sure I have the right wire gauge for my setup and fuses / breakers in the right place. I am still also unsure if I should wire my solar panels in Series or Parallel. I understand the benefits of both in terms of shading and the change in Volts / Amps but I have yet to find any information as to how this effects charging of my batteries. What I have gathered is with an MPPT it does not matter if I increase the AMPS or Volts as the controller is smart enough to charge equally on both?

[chrisski]

1B389EA6-109E-410D-A202-9B188187B2E0.jpeg I’d really check your power requirements. Six lead acid batteries will net yo360 ah overnight or 180 ah planning for bad weather of one night. THat’s not a lot of power. The inverter could draw .5 - 1 amp just to turn on, and that cuts into it. You could not run my laptop for more than 1.5 to 4 hours with that power.

I don’t know if your freezer will run off your inverter. Unfortunately an compressor freezer needs several times its rated wattage to start. Seems you need to buy the inverter and hope it works.

[PySoMaNiC]

I was curious if you guys can help to make sure I have everything I need for my off-grid setup, and hopefully tell me anything I am missing.



List of components

Victron MPPT 100/30

Victron 24V/1200W Inverter

Q-cell 430W Pannels x2

120AH Deep Cycle Lead Acid Batteries x6

15A DC Breakers x 2

40A DC Breaker

DC Breaker Box for 4 Breakers

100A MEGA Fuse x5

MEGA 100A In line Fuse Holder.

100FT 4AWG Wire

30FT MC4 Connectors x2



----BATTERY BANK WIRING-----

I would like to connect my batteries in groups of 2 in series, and have 3 of those in parallel making a 24V, 360AH Battery Bank using 4AWG Wire. (Picture attached of how I believe I should wire this setup).

-----PV WIRING---

I believe I should wire the solar panels in series, having 1 15A Breaker between both solar panels, and another 15A Breaker between the Solar Array and MPPT.

-----BATTERY BANK to INVERTER----

I am going to use 4AWG wire between the battery bank and inverter, I plan to place the 100A MEGA Fuse in line with the positive as close to the battery as possible.

----BATTERY BANK to MPPT----

I was going to use 4AWG wire between the battery bank and MPPT, and I plan to place the 40A Breaker in line with the positive as close to the battery as possible.

-----SOLAR MOUNTING----

I am also planning to run these solar panels outside on the ground, do you recommend or have any mounting equipment for this?

-----GROUNDING THE SYSTEM----

How can I properly ground this system, where do I connect ground and what size wire / grounding rod should I use?





I plan to just run my AC Appliances fron the plugs provided in the inverter, 3.5 CU FT Freezer, some led lights, television, and charge laptops / cell phones / cordless tools etc...


Series-Parallel.PNG