Mega Fuse for MPPT 250/70-85-100

DIY
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1

Hi,

i struggel a littel bit with the Mega Fuse that i need for my MPPTs
i plan three MPPTs 250/ 70 - 85 - 100 on 48V
in the manual is written:

MPPT 150/70 and 250/70
Minimum battery fuse rating 80A - Max 100A
MPPT 150/85A and 250/85
Minimum battery fuse rating 100A - Max 120A
MPPT 150/100 and 250/100
Minimum battery fuse rating 120A - Max 140A

For the cable is a 35mm2 necessary.

But i dont find fuses for 100A, 120A or 140A from Victron.
Any advice?

2

Search for a 125a fuse 48v, they are available.
fuse

1 Like
4

I have a pair of MPPT 250/60 charge controllers and they are specified to have an 80A maximum fuse installed. Unfortunately Victron don’t appear to stock that size of MegaFuse but I was able to source MegaFuses from Littelfuse which are the same dimensions as the Victron MegaFuses. The product I bought was part number 0998080.UX-1M8 ( Fuse - Mega 70V (SF51) 1-M8 hole 80A | Series: Mega 70V SF51) but they have a variety of fuses of different breaking capacities. Note these are also 70V rated which is important because even a 48V system will reach 53-54V or higher when charging.

Hopefully I’m not breaking any community rules by recommending non Victron products but to the best of my knowledge Victron do not supply an 80A MegaFuse. I wanted to use the Lynx distributor/power-in products and so I had to source a suitably sized MegaFuse. If Victron had one available then I would just have bought it from them.

As for the 35mm2 wire, I personally went with 35mm2 just to minimise any voltage drop and because I was buying wire anyway and just added it to my order. However, in my case I’m only pushing 60A through a wire that is fused at 80A so I could easily have dropped cable size quite a bit to 25mm or possibly even 16mm. As I understand it, 35mm2 is the maximum cable size the MPPTs can accept not necessarily what is needed for any given application

5

No worries about recommending non-Victron fuses (Victron doesn’t make the fuses in any case) but for future reference, Victron’s 80A MEGA fuse is PN CIP138080020 for the 80v-rated version (for 48vNom systems).

6

Hi Justin,
Thanks for letting me know I hadn’t broken any rules. :sweat_smile: I did read the posting guide first but couldn’t see anything about that.

It’s interesting that there is a Victron 80A MegaFuse available because I couldn’t see any available a couple of years ago when I was building my system. There were 32V fuses available but not 48V+ at the time. Maybe I just didn’t look hard enough or maybe they’ve been added. Doesn’t really matter I guess.

Thanks again,
Craig.