Need Fuse and wire gauge suggestions

[barbixy]

Hi all,
Does anyone have a schematic showing where all the fuses go, what size fuses and what size wire for each?
System has two 12v 200watt panels, 40amp MPPT, two 100ah LifePo4 batteries, have not figured out what inverter yet (suggestions?) And a fuse block for 12v fridge, led lights, and a small fan.
Thanks for any help

 

[John Frum]

Hi all,
Does anyone have a schematic showing where all the fuses go, what size fuses and what size wire for each?
System has two 12v 200watt panels, 40amp MPPT, two 100ah LifePo4 batteries, have not figured out what inverter yet (suggestions?) And a fuse block for 12v fridge, led lights, and a small fan.
Thanks for any help

System design starts with determining how much power you need in watt hours per day, how many days of autonomy you want and your peak draw in amps.
Your inverter is sized to cover your maximum continuous alternating current draw.
Its generally the largest draw and therefore has a huge influence on the rest of the system design.
Have a look at my signature for a link that will help with step 1 which is an energy audit.

 

[barbixy]

System design starts with determining how much power you need in watt hours per day, how many days of autonomy you want and your peak draw in amps.
Your inverter is sized to cover your maximum continuous alternating current draw.
Its generally the largest draw and therefore has a huge influence on the rest of the system design.
Have a look at my signature for a link that will help with step 1 which is an energy audit.

Thank you

 

[barbixy]

Thank you

Couldn't find the link, but the only DC devices I'm going to run are charging my phone, my laptop, maybe a larger monitor, and an internet hot spot. Everything else is 12volt low draw.

 

[John Frum]

If you are using a smartphone in portrait mode I hear the signatures don't display unless you put the phone in landscape mode.

 

[John Frum]

Will you ever want the option for shore power and/or alternator charging?
What batteries will you be using?

 

[barbixy]

It's for a small camper van. Two 100ah LiFePo4 batteries. This will not be connected to the car battery, and most likely not use shore power.

 

[John Frum]

This will not be connected to the car battery, and most likely not use shore power.

If there is a chance you should probably consider a ul-458 listed inverter/charger from the start.
Its a safety thing.
Also relying entirely on solar to charge you batteries puts you at the mercy of the weather.
Its good to have an alternate charge source.
I've got a ascii art drawing for you.
I added an inverter/charger but I can change that out for an inverter easily.
Some folks find this tricky to read, I would be glad to answer any and all questions you have.

key {
    {} = functional block
    nnnAWG|NNN| = fused busbar position where nnn is the wire gauge and NNN is the fuse ampacity
    nnnAWG|UUU| = un-fused busbar position where nnn is the wire gauge
    <- = uni-directional current flow
    -> = uni-directional current flow
    <-> = bi-directional current flow
    eg = equipement ground
}
fuse_block {
    upstream {
        pos
        neg
    }
    downstream {
        pos {
            010AWG|020|->fridge
            014AWG|010|->lights
            010AWG|020|->fan
        }
        neg {
            010AWG|UUU|<-fridge
            014AWG|UUU|<-lights
            010AWG|UUU|<-fan
        }
    }
}
solar_charge_controller {
    pv {
        pos<-disconnect_switch<-panel_in_series<-panel_in_series
        neg->panel_in_series->panel_in_series
    }
    system {
        pos
        neg
    }
    eg
}
inverter_charger { * 1000 watt continuos rating
    pos
    neg
    eg
}
system {
    pos {
        004AWG|UUU|<->fuse<->battery.1.pos
        004AWG|UUU|<->fuse<->battery.2.pos
        004AWG|125|<-solar_charge_controller.system.pos
        004AWG|125|<->inverter_charger.pos
        004AWG|125|->fuse_block.upstream.pos
    }
    neg {
        004AWG|UUU|<->shunt<->battery.1.neg
        004AWG|UUU|<->shunt<->battery.2.neg
        004AWG|UUU|->solar_charge_controller.system.neg
        004AWG|UUU|<->inverter_charger.neg
        004AWG|UUU|<-fuse_block.upstream.neg
        004AWG|UUU|<->scc.eg
        004AWG|UUU|<->inverter.eg
        004AWG|UUU|<->chassis_bond
    }
}