Hello guys, just had a pop top fitted which I’m really pleased with, the installers ran some cables from the back of the pop top towards the drivers seat where I would position the MPPT controller. The trouble is these are 3mm SQ . Now I know nothing about cable sizing but I did have a quote from 12v planet to supply a 150W panel,75/15 MPPT and a 105 ah lithium battery,on the email they recommended I increase the cable size to 10mm SQ because the run is over 5 meters. So do i need to swop these cables? Will the cable off the solar be 4mm? Do I use a thru crimp where they enter thru the pop top to get from one size to the other? Do I put a fuse at the earliest opportunity ? All so confusing to me.
Solar cable sizing
- Thread starter Jay19711
- Start date
AkA
New Member
Hello, With a 150w panel you will be fine with a 2.5mm or larger cable running to your MPPT and battery. The volatge drop is very small with a 2.5mm. Its still worth adding a fuse on both side of the MPPT to be safe, 10A fuse. Use a water proof box is you have to terminated on the roof but I expect you should have enough length of cable to use a couple of crimps inside the van
Hi
Im about to buy the components to install a 200w flexible panel, which is fitted with 4mm cable to the mc4 connectors .9 meter long.
I’ve got to chop off the MC4 plugs to pass cable through the Scanstrut gland, and renew once inside the poptop canvas.
Is 4 mm solar cable ok to use for the 4-5 meter run to the Mppt? Or should I get 6mm?
I guess I need to get a crimp tool for new mc4 plugs.
From what I’ve read, I don’t need a fuse, just go straight from the panel into the victron 100/20 Mppt ?
Im about to buy the components to install a 200w flexible panel, which is fitted with 4mm cable to the mc4 connectors .9 meter long.
I’ve got to chop off the MC4 plugs to pass cable through the Scanstrut gland, and renew once inside the poptop canvas.
Is 4 mm solar cable ok to use for the 4-5 meter run to the Mppt? Or should I get 6mm?
I guess I need to get a crimp tool for new mc4 plugs.
From what I’ve read, I don’t need a fuse, just go straight from the panel into the victron 100/20 Mppt ?
Yes you can use 4mm PV cable.
6 mm cable is better as it's fatter cable. (Fatter cable is always better)
And yes you need the correct tool to fit an MC4 connector. Ia and MC4 crimper.
but to be honest with you, solar PV cable and MC4 connectors are designed for domestic outside usage.
Once your cables are inside the van you can basically use any 4mm or 6mm cable.
And you can use any connector for example 30mp terminal block or an Anderson connector, etc etc etc .
As long as the cable stroke connector can handle the maximum system current, in your case 20 amps.
Yes you can run the panel direct into the solar controller... Some people fit a switch or a fuse or a disconnect as a way of disconnecting the panel when working on the system... Small panel like 200 w you can always just unscrew the wire from the mppt controler and fit wago over the end or taping up to work on the system
*****
For example on my 200 watt panel on the campervan roof I've used 6mm twin core to get the panel back to the seat base, and connected them to the panel using 30 amp chalk block.
6 mm cable is better as it's fatter cable. (Fatter cable is always better)
And yes you need the correct tool to fit an MC4 connector. Ia and MC4 crimper.
but to be honest with you, solar PV cable and MC4 connectors are designed for domestic outside usage.
Once your cables are inside the van you can basically use any 4mm or 6mm cable.
And you can use any connector for example 30mp terminal block or an Anderson connector, etc etc etc .
As long as the cable stroke connector can handle the maximum system current, in your case 20 amps.
Yes you can run the panel direct into the solar controller... Some people fit a switch or a fuse or a disconnect as a way of disconnecting the panel when working on the system... Small panel like 200 w you can always just unscrew the wire from the mppt controler and fit wago over the end or taping up to work on the system
*****
For example on my 200 watt panel on the campervan roof I've used 6mm twin core to get the panel back to the seat base, and connected them to the panel using 30 amp chalk block.
Last edited:
See more are making up solar panel cables over here.....
[Guide] Solar Cables? . . . - How I Did It -
its time for another guide . . . This time on solar cables.
we use these cables for permanent install and for mobile installs.
lets start with the Solar PV MC4-MC4 cable.
Solar PV cable is not actually standard cable . . . its more specialised.
take a look at this cable i got to make up some extension leads:
you can see in the spec it states:
its time for another guide . . . This time on solar cables.
we use these cables for permanent install and for mobile installs.
lets start with the Solar PV MC4-MC4 cable.
Solar PV cable is not actually standard cable . . . its more specialised.
take a look at this cable i got to make up some extension leads:
RED 15M Solar Panel Extension Cable 4mm² PV Wire Female and Male MC4 Compatible Connector for Solar Panels Photovoltaic Systems : Amazon.co.uk: DIY & Tools
RED 15M Solar Panel Extension Cable 4mm² PV Wire Female and Male MC4 Compatible Connector for Solar Panels Photovoltaic Systems : Amazon.co.uk: DIY & Tools
amzn.to
you can see in the spec it states:
- Ammonia resistance,UV and ozone resistant,pollution and halogen-free ,
- Good fire-resistant performance, protect against short...
that’s great info, thanks Lee, it will make the job even easier for me
Thanks for your thread guide pointer too
Thanks for your thread guide pointer too
AkA
New Member
With a 200w Solar panel you will not need anything bigger than 4mm and in real world 2.5mm will be fine. I have never seen Solar 200w panel produce no more than a 6 amps. in the real world. The calculate output current: 200w / Panel output voltage 18v (typical panel voltage) giving the perfect world 11A. No solar panel is 100%, If you get around 20% your doing well. So the rating question should be based on the system design. A current rating of a 2.5mm cable is about 29amps. Always go 100% safety on cable size and remember the fuse is used to protect the cable.
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