Table

UL/CSA Fuse Class

UL/CSA Fuse Class lookup table with assumptions and boundary notes.

Scope

Fuse class label planning only. It does not choose a fuse, verify holder compatibility, approve replacement, or determine interrupting rating.

Lookup table

Compare common cartridge fuse class markings by form factor, voltage labels, and catalogue context.

Scroll sideways to keep row labels aligned with hidden columns.

Lookup basis uses common fuse class descriptions from manufacturer fuseology and cartridge fuse literature.
Fuse classForm factor lookupCommon voltage labelsLabel cuesBoundary
Class JCartridge fuse300 V, 600 VRejection-style label cueClass label planning only; holder and equipment compatibility still require product data
Class CCCompact cartridge fuse300 V, 600 VCompact control-circuit label cueClass label planning only; holder and equipment compatibility still require product data
Class RK1Renewable / dual-element cartridge fuse250 V, 600 VTime-delay or dual-element label cueClass label planning only; holder and equipment compatibility still require product data
Class RK5Renewable / dual-element cartridge fuse250 V, 600 VTime-delay or dual-element label cueClass label planning only; holder and equipment compatibility still require product data
Class LLarge cartridge fuse600 VHigh-ampere cartridge label cueClass label planning only; holder and equipment compatibility still require product data
Notes
  • Check table values for preliminary lookup and arithmetic checks only.
  • Confirm equipment ratings, product markings, installation conditions, utility requirements, and the local authority requirements before design or field use.