My Multiplus 12/3000 calls for a 400A Class T fuse. Many suppliers are out of stock but I find that some Class T fuses available are slow blow and some are fast acting JJN and extremely fast acting TJN. What type does Victron recommend?
As usual, the devil is in the details...and so is salvation!
Recall that OCPD has two functions: current limiting and protection against fault current. In the recreational marine industry, where I have experience, the largest conductor in common use is AWG 4/0 Boat Cable with 105C insulation. ABYC, the Standards writing body for my industry, limits AWG 4/0 in a machinery space to 264.8A. I have to weigh this requirement with the Victron spec and the Class T trip curves (Time vs. current) and make a decision.
There is no Standards based reason why you can't parallel, B+ conductors, each individually protected by a separate OCPD and two parallel B- conductors. The gotcha is in sizing the ABYC required case ground.
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