TR10R – GOULD 10A 250V CLASS RK5 TIME DELAY FUSE

Both Class RK1 and RK5 fuses share the same physical dimensions and will fit the same holders, but they are not interchangeable for performance purposes. Class RK1 fuses (like Bussmann's LPS-RK series) have tighter current-limiting characteristics and a higher 200kA interrupting rating standard, whereas Class RK5 fuses like the Gould TR10R are current-limiting but with a slightly less restrictive let-through. You can upgrade from RK5 to RK1 in the same holder, but you should not downgrade from RK1 to RK5 without an engineering review.

Yes — the time-delay (dual-element) design of the TR10R makes it well-suited for motor branch circuits, transformer primaries, and other inductive loads that draw a harmless inrush current at startup. The delay element rides through these brief surges without nuisance blowing, while the fast-acting element still provides rapid response to genuine short-circuit faults, keeping your equipment protected.

Gould's fuse division was acquired by Ferraz Shawmut, which later became Mersen. The TR-R series fuse line has been continued under those successor brands. Northern Breaker Group specialises in obsolete and hard-to-find electrical components, so whether you need original Gould stock or a verified modern equivalent, contact us and we'll source the right option for you.