250V 5A Square Ceramic Body Fast Acting Fuses Surface Mount 1808 6125 2410
Payment & Shipping Terms:
|Minimum Order Quantity:||1000PCS|
|Delivery Time:||5-7 Days|
|Payment Terms:||T/T, Western Union|
|Supply Ability:||100000000PCS Per Month|
|Name:||Surface Mount Fuses||Size:||1808 6125 2410|
|Rated Current:||5A||Rated Voltage:||250vac|
|Speed:||Fast-acting||Plating:||Ag Plating(Default) Or Sliver Plating|
slow blow glass fuse,
radial lead fuse
Brand New 250V 5A Square Ceramic Body Fast Acting Surface Mount Fuses 1808 6125 2410
Fast-acting Type (Fast blow-F)
Wide range of current rating available
Wide operating temperature range
Low temperature de-rating
Tape and Reel for automatic placement
Conflict free metals
|• LED lighting||• Notebook PC||• Battery devices||• LCD/PDP devices|
|• LCD backlight inverter||• Portable Devices||• Power supply||• Networking devices|
|• PC server||• Cooling fan system||• Storage system||• Telecom system|
|• Wireless base station||• White goods||• Game console||• Office equipment|
|• Digital camera||• Industrial equipment||• Medical equipment||• Automotive devices|
|Agency||Ampere Range||Agency File Number|
|UL||50mA ~ 7A||E340427(JDYX2)|
|CUL||50mA ~ 7A||E340427(JDYX8)|
|% of Ampere Rating(In)||Blowing Time|
|100% * In||4 hours Min|
|200% * In||120 sec Max|
|1000% * In||10ms Min|
|SEF0200||200mA||250VAC||50A@300VAC 50A@250VAC 200A@125VAC||0.96||0.148|
A slow blow fuse is different from a fast acting fuse in its capability to withstand transient pulse currents, i.e., it can withstand the surge current upon power-on/off, thus ensuring the equipment works normally. Therefore, slow blow fuses are often called time-delay fuses. Technically, a slow blow fuse features a higher I2t value, and it requires more energy to blow, so it is more capable of withstanding pulses compared with a fast acting fuse of same rated current.
When an overcurrent occurs in a circuit, the breaking time of a slow blow fuse takes longer than that of a fast acting fuse because of the larger I2t. Is it less protected this way as some people are worried? The answer is no. Once the circuit fails, the overcurrent will last and corresponding energy released will go beyond the I2t of the fuse until it blows out. The timing difference of slow blowing and fast acting is not significant to their protection. Slow blowing will affect the protection performance only when sensitive components existing in the protected circuit need to be protected.
Due to the previous difference, slow blow and fast acting fuses are applied to different circuits. Fast acting fuses must be used in purely resistive circuits (no or fewer surges) or the circuits where IC and other sensitive components need to be protected, while slow blow fuses are preferably used in capacitive or sensitive circuits where surges occur upon power-on/off and power input/output. Apart from circuits for IC protection, most applications with fast acting fuses can be replaced with slow blow ones to enhance anti-surge capability. Contrarily, replacement of applications with slow blow fuses to fast acting ones may cause the fuse to break as soon as the equipment is switched on and fails to work.
Furthermore, economic consideration is also an indirect factor for selection because a slow blow fuse is much expensive than a fast acting one.
A resistor is available for a certain load. If the current flowing through the resistor goes beyond the limit, it will be burned and the circuit will be open. At this point, a resistor is similar to a fuse, i.e., the current can be interrupted upon overcurrent. This seems like a fuse function. In this way, some manufacturers change the fuse in its original design to cheap fuse resistors to keep cost down, presenting customers with superficial security.
However, is a fuse resistor able to substitute a fuse to have the same function? The answer is obviously no.
As we know, a good fuse must possess three essential functions: protection, load bearing and safety, while a fuse resistor may not be able to work well in all three aspects.
The protection function covers overload protection and short circuit protection. Specifically, a fuse must operate within the specified time when an unexpected overcurrent, even an extremely short overcurrent, occurs in the circuit, so as to protect the circuit and parts. A fuse resistor may not be as accurate as the fuse in terms of technical parameters like starting time and operation duration, and thus cannot ensure overcurrent protection. It only works to some extent for short current.
The load bearing function of a fuse is ensured by the I2t value, which enables a fuse to withstand pulse shocks of a certain energy from switching operations. We should calculate and evaluate this value before fuse selection. Nevertheless, a fuse resistor has no similar technical indexes, so it may be blown by a pulse if the value is small or fail to protect the circuit if it is large.
As for safety, a fuse can be assured through rated voltage, interrupting capacity and other indexes, especially safety compliance certification by an authorized third party. A fuse resistor is not a safety component, so it does not need certification. Its safety is therefore questionable. Furthermore, it has insufficient protection, and it is hard to ensure no hazards occur during the breaking process.
In conclusion, a fuse resistor may blow upon overcurrent, but it cannot work the same as a fuse. In most applications, it will not be appropriate to replace a fuse with a fuse resistor to cut cost.