How to identify fuses and circuit breakers
Protective devices interrupt current under overload or short-circuit to protect wiring and equipment.
Have one in front of you? Photograph it and get an evidence-backed identification.
Identify from a photoIdentification clues
- —Rated current and voltage
- —Trip curve (B/C/D) or fuse class (gG, aM, fast, slow)
- —Breaking capacity (kA)
- —Physical format and dimensions
- —Pole count
Common types
- —Cartridge fuse
- —Blade fuse
- —MCB
- —RCD / RCBO
- —MCCB
- —Motor protection breaker
Typical failure modes
- —Nuisance tripping
- —Contact welding
- —Thermal degradation of holder
- —Wrong rating fitted
What a replacement must match
- —Match rating, curve and class exactly
- —Match breaking capacity
- —Match format and busbar/holder
- —Never upsize without engineering review
Photos that help identification
- —Photograph the printed front
- —Show the side label
- —Show the holder or rail
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Find a replacementRelated components
General reference information. Always verify against the manufacturer’s documentation before ordering or installing.