What Size 12v Cable?

[allupstairs]

Interior LED lighting takes very little current. 1mm twin core confined in insulation ( as behind panels etc) is okay for 11A and would carry a load of 132W which is a lot of LED`s !! What size have you got?

i haven’t bought any yet was waiting for some advice on here, Will more than likely buy extra to use for other projects... some mood lighting, also possibly some sockets.

 

[nstirling5]

Hi

Looking to install a shut off switch between solar panel (100W) and charge controller (Victron SmartSolar MPPT 75/10) but I understand that there should also be a fuse between the solar panel and the charge controller. Can anyone advise on the best solution?

Thanks

 

[travelvolts]

Why do you want to do that? No, you don't need a fuse.

 

[nstirling5]

Thanks for your response. The reason for installing the shut off switch is so that I can follow Victron's guidance on order of connecting up system - battery before solar panel. I plan to remove the leisure battery when not being used, so a shut off switch would allow me to isolate solar before removing battery and then reattach battery before turning solar back on. Would avoid the need to cover solar panel when connecting up system. I have read that you should have three fuses: between solar panel and charge controller, between charge controller and battery and between battery and load. I had only planned to have two fuses, one between charge controller and battery and the other between battery and load. I plan to use anderson connectors between charge controller and battery and between battery and load so that the battery can be removed easily.

Does this make sense? Grateful for any further advice you can provide. Not having the third fuse or the shut off switch would certainly make the system easier to install.

 

[Dilbert]

I plan to use anderson connectors

Just use another Anderson connector on the solar input to the charge controller.

 

[Dellmassive]

as @travelvolts said, no need to fuse a 100w panel, (about 6A 25v max)

but as you see a removable fuse or switch is beneficial on the PV side of the solar controller if you plan to disconnect the battery side.


i use a double pole DC breaker on my Solar shed . . . Circuit Breaker, DC 250V 2P

but just use MC4 connectors on the van (next to the mppt) . . . . . Crimping Tools for 2.5/4.0/6.0mm² Solar Panel PV

50A Anderson : Battery Connector 50 Amps (crimper HS-16 HS-16 1.25-16mm? Cable Crimper )


in the below you can see i use MC4 solar PV conectors for the panel PV side,

and 50A Anderson connectors for the battery / power side.

shed:



van:




.

You could also use an isolator switch like this one : Isolator switch. | travelvolts








.

any switch or fuse will work, as long as its rated over say 30vdc and 20A (to stop it getting hot)



...




I've also see this style used before: https://amzn.to/3d6TYL9







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[nstirling5]

Thanks for all your advice. Would the circuit breaker not have the advantage of tripping in the event of a lightning strike (unlikely, but you never know)?

 

[Dellmassive]

Thanks for all your advice. Would the circuit breaker not have the advantage of tripping in the event of a lightning strike (unlikely, but you never know)?

unfortunately those types of fuse switches are based on a thermal bi-metalic trips and will offer no such protection against lightning.

but are handy for switching off you solar system in the van. . . .

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.

 

[travelvolts]

Can I ask why you want to remove the leisure battery? Surely if the van is not being used then the battery would benefit from the maintenance charge from the solar panel?

 

[nstirling5]

I most likely will leave the leisure battery in during the warmer months of the year when it is used frequently as a day van / camper. However, as it is my only vehicle, I don't want to be carrying unnecessary weight around the rest of the time.

 

[t0mb0]

I most likely will leave the leisure battery in during the warmer months of the year when it is used frequently as a day van / camper. However, as it is my only vehicle, I don't want to be carrying unnecessary weight around the rest of the time.

That is some serious dedication to weight saving, even a 30kg leisure battery in a very lightly loaded (2600kg) van is barely over 1% of the total weight.

 

[Nukeproof@36]

Hello sorry got another wiring question. I got a pre wired system from rayne automotive. works perfectly, but some of the wiring is a little too short for the runs iam using. So I need to extend the lights. I have 4 led lights in the celling and want to check I've worked this out right before I go ahead and extend the wires. The are wired in parallel and looking at the rayne website, they are 1.8 Watts each from what I can tell. So if I am right 7.2/ 12= 0.6amps. Is that right or am I completely wrong? Would 0.5 gauge be enough?

 

[DXX]

Hello sorry got another wiring question. I got a pre wired system from rayne automotive. works perfectly, but some of the wiring is a little too short for the runs iam using. So I need to extend the lights. I have 4 led lights in the celling and want to check I've worked this out right before I go ahead and extend the wires. The are wired in parallel and looking at the rayne website, they are 1.8 Watts each from what I can tell. So if I am right 7.2/ 12= 0.6amps. Is that right or am I completely wrong? Would 0.5 gauge be enough?

Have a look at this link, length of cable is especially important with DC. If in doubt go bigger and make sure that any cable joint matches the cross sectional area.

Voltage Drop Calculator | 12 Volt Planet

Use our Voltage Drop Calculator to select the correct Cable for your campervan, motorhome or boat wiring application. Auto and Marine Electrical Components from 12 Volt Planet - Cable Size Calculator

www.12voltplanet.co.uk