The DF2KN1631 is a set of three DIN NH3 blade fuses from the Schneider TeSys GS range, rated 630 A at 500 V AC with a gG (general-purpose) fuse curve. The gG characteristic means it handles both overloads and short-circuits in cable and distribution protection — not motor starting, where an aM curve would be the better fit. The NH3 blade size defines the physical envelope; it slots into standard NH3 fuse bases and switch-disconnectors in a panel.
Sourcing reality — obsolete, no direct replacement
Schneider has marked the DF2KN1631 as obsolete. No official successor order code exists, so a parametric cross-reference is the only path.
The 630 A line-rated current is the continuous current the fuse can carry without nuisance opening at 40 °C ambient. The 500 V AC operational voltage is the maximum system voltage it can interrupt — common for 400 V three-phase distribution but not for 690 V circuits. The gG curve means the fuse blows faster than a gL (cable protection) fuse at high fault currents but slower than an aM (motor) fuse on inrush; it is sized for distribution feeders, not individual motor branches.