Reference boundary

Label-reading reference only. It does not select a fuse, verify holder compatibility, approve replacement, or replace fault-current study review.

Reference table

Decode common fuse label fields such as ampere rating, voltage rating, class, interrupting rating, and time-delay markings.

Reference basis uses common fuse label fields from manufacturer fuseology and product literature.
MarkingMeaningExampleBoundary
AAmpere rating30 ARead directly from the fuse label; load and holder selection are separate checks
V AC / V DCVoltage rating600 V ACThe circuit voltage and current type must be within the marked rating
ClassFuse class or familyClass J, CC, RK1, RK5, LClass markings do not by themselves confirm holder or equipment compatibility
IR / kAInterrupting rating200 kAAvailable fault-current study and equipment ratings remain separate checks
Time delayDelay characteristic markingTD, D, time-delayTrip behavior depends on the fuse family and manufacturer time-current data
Current limitingCurrent-limiting fuse markingCurrent limitingCoordination and let-through review require manufacturer curves
Use notes
  • Use this table for preliminary reference and arithmetic checks only.
  • Confirm equipment ratings, product markings, installation conditions, utility requirements, and the local authority requirements before design or field use.