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?
asked
Class T fuse speed for Multiplus
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.
