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Description: This is a glass ferrule type fuse. It fits great with our 5mm fuse clips. The fuse is rated for 250VAC, up to 200mA. Fuses are pretty simple, if more than 200mA pass through the fuse, the small filament inside the fuse heats up and breaks (like a light bulb burning out). The circuit is then broken and hopefully your circuit is saved from molten destruction.

For smaller loads, you may want to checkout a PTC (aka resettable fuse) listed below. They handle less current (500mA) but can be set and reset many times without doing harm to your system.

This is a perfect replacement fuse in case you blow the fuse in your SparkFun digital multimeter. Not sure how to replace the fuse? Checkout our How to use a multimeter tutorial.


  • 250mA max @ 250VAC
  • Glass Cartridge

Dimensions: 5 x 20mm


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Customer Comments

  • i’m a recovering non-fuse-aholic :-) After numerous expensive lessons in recent years, i’m using more fuses in more places. Fuses are not supposed to be current-limiters, but just provide ‘catastrophic’ protection in WHOOPS cases. Proper fusing will likely protect ‘at least some of’ your circuit :-)

  • For those who want to somehow protect their circuits from “epic failure” consider this. A fuse will not only protect your circuit, but it will appear “blown” (i.e. open) thus giving you a clue as to why your circuit isn’t working.

    A PTC is more convenient because you don’t need to replace it, but because it is self-resetting, your circuit will appear “dead” but the PTC will still appear as a low resistance (maybe not a dead short) without power. However, it will be hot when powered and “activated” so you could do the “switch and feel” method if your voltages are safe to touch (most PTCs can’t handle high voltages anyway)

  • From the description:

    250mA == 200mA > 500mA

  • “They handle less current (500mA) but can be set and reset many times without doing harm to your system."
    Well going by the fact that this fuse is apparently 200mA, the PTCs would handle more current at supposedly 500mA.

    • I wouldn’t be so sure it’s 200 mA. Both 200 and 250 mA are mentioned as the rated value above. So how about giving us the Bussman part number to clear this up, SFE?
      Either way, 200 mA will never trip this fuse; you need to exceed the rated value significantly to actually blow the fuse. While conceptually simple, fuses are full of surprises when you actually try to use them. Normally a fuse will not protect your circuit; rather a fuse is there to keep your circuit from causing a fire and burning down your house. By the time a fuse blows, your circuit is probably already toast.
      When it comes to the PCT (at least the one listed in Related Products below), the rating is 250 mA. That is, you can run 250 mA through it forever and it will not trip. This PCT will trip when more than about 300 mA passes through it (the actual value depends on the ambient temperature). At room temperature, it would trip at about 500 mA, which is probably where the 500 mA number comes from.
      There is no reason to use a PTC instead a fuse for small loads either. A fuse will always respond faster to an overload, is more predictable than a PTC, and it will not reset itself and potentially cause further damage.
      And sorry about ranting in a response; it certainly isn’t aimed at you, mowclus.

      • This is something people new to the field need to know: fuses don’t blow in absolutely predictable ways. The mechanism (as you pointed out) is dependent on environmental temperature and the duration of the peak current draw. The actual current draw can exceed the value of the fuse by over 3x the rated current if the duration of the current draw is short enough.
        The one thing I’ve never understood though is the voltage rating. Fuses don’t care what the voltage passing through them is. It could be 5 volts or 100. Fuses blow when the power dissipated in the internal element exceeds the thermal limit of the material and that value is entirely dependent on a combination of current, the resistance of the internal element, and environmental temperature.

        • The voltage rating is kind of like the rating on a capacitor, in that you don’t want to use a (say) 32 volt fuse in a 110 volt circuit. The reason being is that the higher the voltage, the longer the distance that an arc can form. If the voltage is too high, the fuse cannot safely interrupt the current. An arc might allow current to just keep on flowing until something else fails, or the fuse could get hot enough to damage/ignite things around it (which somewhat defeats the purpose of having a fuse)

        • Fuses have a voltage rating because the voltage is proportional to the arc distance. The voltage won’t affect whether you blow a fuse, but if you blow a fuse above it’s voltage rating, it might arc across the contacts and continue to conduct current. A longer element means a longer gap the arc has to jump and a higher voltage rating.

Customer Reviews

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tres content

je suis vraiment tres content de votre prestation je nais eu aucun soucis ni au moment de la commande ni pour l'expedition. je remercie toute votre équipe Boudjemaâ Messelem