63A 500VAC NH000 GL/gG 120kA ABB OFAF000H63 ...

Knife-blade type fuse for larger electrical installations. For example this fuse can be found in following places:

• Electrical cabinets
• Large electrical devices
• Industrial electrical installations

Changing the fuse (while electricity is on) requires special tool. Changing large fuses on the go is nor recommended while the load is connected. There is possibility to create devastating electrical arcs. So disconnect the load if possible and then exchange the fuse.

Fuses technical details:

• Size class:
  • NH00
• Speed class:
  • gL/gG
• Nominal maximum operating voltage:
  • 500VAC
• Nominal maximum current:
  • 10A
• Breaking capacity:
  • 120kA
• Blown fuse indicator:
  • Located on side

Common information about the industrial fuse markings. Industrial fuses among other fuses have various intended uses and because and as a result they have few different parameters, which can vary between fuses. Here is a list and explanation of the most important parameters according to the IEC 60269 standard:

• Fuse size designation, current-range and nominal blade length:
  • NH000
    • 6...160A
    • 78mm
  • NH00
    • 6...160A
    • 78mm
  • NH0
    • 6...160A
    • 125mm
  • NH1
    • 80...250A
    • 135mm
  • NH2
    • 125...400A
    • 150mm
  • NH3
    • 315...640A
    • 150mm
  • NH4
    • 500...1000A
    • 200mm
  • NH4A
    • 500...1250A
    • 200mm
• Typical fuse speed markings:
  • Extremely fast acting:
    • aR:
      • Partial-range breaking capacity (short-circuit protection only) for the protection of Power Semiconductors.
    • gR:
      • Full-range breaking capacity (overload and short-circuit protection) for the protection of Power Semiconductors or rectifiers.
  • Fast acting:
    • gG:
      • Full-range breaking capacity (overload and shortcircuit protection) for general applications.
    • gL:
      • Same as gG (old marking practice).
    • gM:
      • Full-range breaking capacity (overload and shortcircuit protection) for the protection of motor circuits.
    • gPV:
      • Protection of solar photovoltaic arrays.
  • Slow acting:
    • aM:
      • Partial-range breaking capacity (short-circuit protection only) for the protection of motor circuits.
  • Less common markings:
    • gS:
      • Full-range breaking capacity (overload and short-circuit protection) for the protection of batteries & power semiconductors in drives.
    • gB:
      • Full-range breaking capacity (overload and shortcircuit protection) robust for mining application.
    • gTr:
      • Full-range breaking capacity (overload and shortcircuit protection) for protection of transformers.
    • gRL:
      • Full-range breaking capacity (overload and short-circuit protection) for the protection of Power Semiconductors, Line & Cable Protection.
    • gN:
      • Conductors sized to North American practice
• Fuse breaking capacity:
  • Typically indicated in kA (kiloamperes, ie in thousands of amperes). This value means that the fuse is capable of break the xkA amount of current generated by short circuit/fault condition and as an outcome fuse will successfully extinguish the arc inside the fuse.