# Inline fuse for solar panel regulator?



## alshymer (Nov 4, 2007)

Hi
I need to insert an inline fuse 6inches from the battery in the 4mm cable that goes to the MPPT controller.
All the inline fuse holders seem to be 2.5mm cable for up to a 30amp fuse.
Can I use one of these or can someone suggest a better one?
Thanks for any help.
Regards
Alshymer


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## listerdiesel (Aug 3, 2012)

2.5mm cable will be OK, it will blow a 30A fuse in a short-circuit situation.

The Panels use a very heavy 4mm cable with a sheath size that is almost as big as the 6mm cable we have used in our setup, not sure why unless it is double-sheathed.

On our trailer/RV, I have fitted a multi-fuse fuseboard, taken the load and the charging feeds to it and used conventional vehicle fuses, there is provision for battery cables to be taken off by M5 terminals.

Like this one: ebay 170743050618

Peter

Edit: There is this one which is heavier rating:

http://uk.rs-online.com/web/p/inline-fuse-holders/2506285/


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## 747 (Oct 2, 2009)

A bigger diameter cable is only used to minimise voltage drop in long runs of low voltage cable. The actual voltage drop is minimal in most motorhome applications and 2.5 would have probably been sufficient. there are websites which can work out the voltage drop in a particular cable over a particular length.

I have a 90 watt panel with 2.5 cable of about 10 metres length. It keeps my batteries topped up, so I am satisfied.

I would assume you have a large wattage of panels as I only have a 7.5 amp fuse and I can run my 80 watt wind turbine and 90 watt solar at the same time (safely). I expect your bigger supply of watts justifies the 30 amp fuse.


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## listerdiesel (Aug 3, 2012)

We've run our own panel wiring in 6mm as we have a fairly long wiring run, the actual consumption is fairly low, mostly lighting and gas ignitors.

Battery cables to the winch are in 16mm but the rest is 6mm up to the fusebox.

Peter


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## alshymer (Nov 4, 2007)

*In line fuse for solar controller*

Hi
Thanks for your replies.
I have an Alden 120watt panel. I was just concerned about going down to a lesser gauge cable for the 6inch run between the 4mm runs.
The item on EBay looks great but a little over the top for what I need.
Kind regards
Alshymer


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