I’ve seen conflicting information for protecting my 3000W Multiplus inverter, in Victron’s system guides they show a Mega fuse. Many installers recommend a Class T fuse.
Does anyone from Victron have a recommendation for which fuse type is best to protect the Multiplus DC input?
Hi AS. If you want it in Victron-speak, they have a spread of basic fuses listed in their product range: https://www.victronenergy.com/upload/documents/Datasheet-Midi,-Mega-and-ANL-fuses,-and-fuse-holders-EN.pdf
There's some fuse advice also here: https://www.victronenergy.com/upload/documents/Wiring-Unlimited-EN.pdf
What you may find is that many electricians cut their teeth with Class T fuses on ac systems. They can do 'very-fast' response if selected for that, but with dc perhaps not so important, nor even desired?
I use ANL, just a bit bigger, higher V-rating, bigger terminals in the holder to suit 70mm2 wire. In my country they're often called 'forklift fuses' and seem to be commonly used for batt wiring.
Blue Seas also have a wide range of fusing and holders that would suit, also eBay if you're cheaping it.
You could humour your installer too if you choose..
Different fuse types have different capabilities in terms of breaking DC current. For SLA chemistry, they're much the same (aside from cost). For lithium chemistry, the short circuit current could be extremely high, and that is where UL Class T fuses (or equivalent) comes in - they can safely and reliably break a multiple kilo-amp short.
https://www.victronenergy.com/live/dc_distribution for some additional info. Ultimately the choice of fuse is an engineering decision for the system designer which considers a whole range of factors.
