Mpp solar 2024 wiring gauge and fuses help needed

[bearpower]

I am having trouble finding the correct gauge of wire and fuses or circuit breakers that I should be using. I have an MPP solar pip2024 lv-mk aio inverter/cc

I will be installing it into a converted school bus RV.

I have two litime 12v 100 amp/hr tm batteries that I will connect in series to make 24 volt.

I will connect three jinko solar 275 watt panels in series. The VOC is 39.1. The max PV input voltage of the inverter is 145 volts.

My questions are:
1. What gauge of wire between the batteries and the inverter?
2. Should I use a fuse or a breaker between the batteries and the inverter? If so which one and what size?
3. What gauge of wire should I use to connect my solar panels to the MPP solar 2024 unit?
4. What type of fuse or breaker should I use between the solar panels and the MPP solar unit?
5. Is there anything else I'm missing to make this a safe and well functioning unit?
6. What's the best way to get solar panel wires through the roof of a school bus? The gland that Will recommends on his website appears to be for a smaller gauge wire then I'm going to need for my three 275 watt panels.

Any recommendations of where to buy would be much appreciated.

 

[pvgirl]

1. This will depend on the length between your batteries and inverter and if cables are run in the open or thru enclosed spaces. 1/0 recommended.
2. A class t fuse should be used, 150 amp if used with 1/0 wire.
3. without knowing Isc for the solar panels, I can't answer this one for sure, but with those panels you should be fine with standard 12 or 10 awg solar wire.
4. Midnite solar's MNEPV Breakers in their baby box, rating should be based on Isc of solar panel * 1.56 (since these panels are in series the current will be based on one panel, and the voltage will go up with each panel added in series)
5. Battery switch is common add on, make sure it can handle the max voltage of the battery, and current of the battery(use fuse size)
6. PV wires are standard in sizes of 12 or 10 awg, and rated to 600v volts, nothing bigger should be needed in your setup. Both of which should be fine in that gland.

 

[bearpower]

Thanks so much!

Isc is 9.15 amp

I wonder why the inverter's manual recommends 4awg wire for battery to inverter?

I plan to install the inverter in a small cabinet. The inverter would be screwed to the wall of the cabinet and the batteries would be on the floor so however many inches it takes to get from the batteries to the inverter I'm sure it will be less than 2 ft. I expect to have a door on the cabinet it could be vented if need be but to keep pets and children away from the electricity. Would that qualify as a closed or open space for the wires?

 

[pvgirl]

4 awg the absolute minimal cable size you could use for that inverter, but I would not recommend a cable that small as it will get quite warm when under a heavy load, espiclly if in an enclosed cabinet. Providing some ventilation would be good, as the inverter will produce heat while operating.

Based on that Isc you can use a 15amp pv breaker and wire would need to be a minimum of 14awg for the solar pv input.

 

[derk diggla]

1. This will depend on the length between your batteries and inverter and if cables are run in the open or thru enclosed spaces. 1/0 recommended.
2. A class t fuse should be used, 150 amp if used with 1/0 wire.
3. without knowing Isc for the solar panels, I can't answer this one for sure, but with those panels you should be fine with standard 12 or 10 awg solar wire.
4. Midnite solar's MNEPV Breakers in their baby box, rating should be based on Isc of solar panel * 1.56 (since these panels are in series the current will be based on one panel, and the voltage will go up with each panel added in series)
5. Battery switch is common add on, make sure it can handle the max voltage of the battery, and current of the battery(use fuse size)
6. PV wires are standard in sizes of 12 or 10 awg, and rated to 600v volts, nothing bigger should be needed in your setup. Both of which should be fine in that gland.

Awesome mate that's confirmed what I thought thankyou for that and the inverter is only going to be 1500mm away from batteries and 15m away from panels