What is the difference between DC fuses and AC fuses？

What is the difference between DC fuses and AC fuses

According to different application circuits, current-limiting fuses can be divided into two categories: DC and AC. DC fuses are used in DC circuits, and AC fuses are used in AC circuits. There are certain differences in process, arc energy generated, size, price, etc. Generally speaking, AC and DC fuses cannot be used for general use, otherwise the components may be burned out in the event of a short circuit fault, but it is still possible to use them temporarily for a while in an emergency. Let's take a look at the difference between DC fuses and AC fuses. 1. What is the difference between a DC fuse and an AC fuse?

Current-limiting fuses refer to fuses that can safely cut off all possible currents within the rated current and current-limiting range. They are divided into two categories: DC fuses and AC fuses. These two fuses have the same function. The shape and structure are also very similar, but there are still some differences in other aspects. The main differences between AC and DC fuses are:

1. The process of breaking current is different

The alternating current conducts alternately in a sinusoidal waveform, and each cycle has a zero-crossing point. At this time, the power value is the lowest and it is easy to extinguish the arc; while any waveform of the direct current does not have a zero-crossing point. When breaking the DC short-circuit fault current, it depends on the rapidity of the fuse. Vaporization and diffusion adsorption and cooling of quartz sand force the arc to be extinguished, so it is much more difficult than breaking the AC arc.

2. The generated arc energy is different

Under the same rated voltage, the arcing energy generated by the DC arc is more than twice that of the AC arcing energy.

3. Different sizes

According to the recommended data of the International Fuse Technology Organization, for every 150V DC voltage increase, the fuse body length should be increased by 10mm; while the AC fuse body length generally adopts 292-442mm.

4. Different prices

DC fuses have higher arc extinguishing performance, so DC fuses are generally more expensive than AC fuses at the same level.

2. Is the fuse universal for AC and DC?

There are certain differences between AC fuses and DC fuses, but both are current-limiting fuses, so can they be used instead of each other?

Generally speaking, DC fuses and AC fuses cannot be used universally, because DC arc extinguishing is more difficult than AC arc extinguishing. If an AC fuse is used in a DC circuit, when a short circuit or overload occurs, the fuse will blow. The arc extinguishing ability cannot reach the capability of the DC fuse, prolonging the arc extinguishing time and possibly causing damage to the components.

However, this is not certain. After all, DC fuses and AC fuses have the same function. If there is no short-circuit fault, there will be no impact. Therefore, it can be temporarily used in emergency situations, but it must be replaced in time after use. .