Rated voltage The nominal working voltage of a fuse, codenamed Un, is generally rated at 32V, 60V, 125V, 250V, 300V, 500V, 600V, and 1200V. Fuses can be used at a voltage not exceeding their rated voltage, but are generally not approved for use in circuits with a circuit voltage greater than the rated voltage of the fuse. Voltage drop When the rated current is applied to the fuse, the voltage measured at both ends of the fuse when the fuse reaches Thermal equilibrium, that is, when the temperature is stabilized, is Ud. Due to the voltage drop at both ends of the fuse having a certain impact on the circuit, there are clear provisions for voltage drop in European regulations. Fuse resistance Usually divided into cold resistance and hot resistance, cold resistance is the resistance value measured by a test current less than 10% of the rated current at a fuse temperature of 25 ℃. The thermal resistance is converted from the voltage drop measured at the full rated current value as
Precautions for installation of Thermal cutoff: 1. When the lead wire is bent for use, it should be bent from the part more than 6mm away from the root; When bending, it is not allowed to damage the roots and leads, and it is not allowed to forcefully pull, press, or twist the leads. 2. When the thermal fuse is fixed by screws, riveting, or wiring terminals, it should be able to prevent mechanical creep and the occurrence of poor contact. 3. The connecting components should be able to work reliably within the working range of the electrical product, without displacement due to vibration and impact. When conducting wire welding operations, the heating humidity should be limited to the minimum, and attention should be paid not to apply high temperatures to the thermal fuse; Do not forcefully pull, press, or twist the thermal fuse and leads; After welding, it should be immediately cooled for more than 30 seconds. 5. The thermal fuse can only be used under the specified rated voltage,
Precautions for installation of SEFUSE Thermal cutoff: 1. When the lead wire is bent for use, it should be bent from the part more than 6mm from the root; When bending, it is not allowed to damage the roots and leads, and it is not allowed to forcefully pull, press, or twist the leads. 2. When the thermal fuse is fixed by screws, riveting, or wiring terminals, it should be able to prevent mechanical creep and the occurrence of poor contact. 3. The connecting components should be able to work reliably within the working range of the electrical product, without displacement due to vibration and impact. When conducting wire welding operations, the heating humidity should be limited to the minimum, and attention should be paid not to apply high temperatures to the thermal fuse; Do not forcefully pull, press, or twist the thermal fuse and leads; After welding, it should be immediately cooled for more than 30 seconds. 5. The thermal fuse can only be used under the specified rated voltage
According to temperature, it can be divided into: 73 degrees 99 degrees 77 degrees 94 degrees 113 degrees 121 degrees 133 degrees 142 degrees 157 degrees 172 degrees 192 degrees 216 degrees 227 degrees 240 degrees 70 degrees 77 degrees 84 degrees 92 degrees 95 degrees 105 degrees 110 degrees 115 degrees 121 degrees 128 degrees 130 degrees 139 degrees 141 degrees 144 degrees 152 degrees 157 degrees 169 degrees 184 degrees 185 degrees 192 degrees 216 degrees 227 degrees 228 degrees 240 degrees 250 degrees 280 degrees 320 degrees Due to the certain overload capacity of various electrical equipment, it is allowed to operate for a long time under certain conditions; When the load exceeds the allowable value, it is required to protect the melt from melting within a certain period of time. Some devices have a high starting current but a short starting time, so it is required that the protective characteristics of these devices should meet the needs of equipment operation. It is required
① Single direct starting motor melt rated current=(1.5-2.5) × Rated current of the motor. ② Total protection melt rated current of multiple direct starting motors=(1.5-2.5) × The sum of the currents of each motor. ③ Reduced voltage starting motor melt rated current=(1.5-2) × Rated current of the motor. ④ Rated current of winding motor melt=(1.2-1.5) × Rated current of the motor. ⑶ Rated current of low-voltage side melt of distribution transformer=(1.0~1.5) × Rated current on the low-voltage side of the transformer. (4) Rated current of parallel capacitor bank melt=(1.43-1.55) × Rated current of capacitor bank. (5) Rated current of welding machine melt=(1.5-2.5) × Load current. Rated current of electronic rectifier element melt ≥ 1.57 × Rated current of rectifier components. Explanation: The numerical range of the rated current of the melt is to adapt to the standard component rating of the melt.
The action of a fuse is achieved by the melting of the melt, and when the current is high, the time required for the melt to fuse is shorter. When the current is low, the melting time required for the melt to melt is longer, and it may not even melt. Therefore, for the melt, its operating current and operating time characteristics, namely the ampere second characteristics of the fuse, are inverse time characteristics. Each melt has a minimum melting current. Corresponding to different temperatures, the minimum melting current also varies. Although this current is affected by the external environment, it can be disregarded in practical applications. The ratio of the minimum melting current of the melt to the rated current of the melt is generally defined as the minimum melting coefficient. Commonly used melts have a melting coefficient greater than 1.25, which means that a melt with a rated current of 10A will not fuse when the current is below 12.5A. The relationship between fuse
MB:+86 13924633629 Ms.vicky
E-mail: waimao@xcfuse.com
Factory :
XC Electronics(Shenzhen)Corp.,LTD
Add: Jinyuan Industrial zone,Heao, Henggang, Shenzhen 518115,China
Shenzhen branch: Shenzhen Xucheng Electronic Commerce co.Ltd
Add: 8-15 Jinyuan Industrial zone,Heao, Henggang, Shenzhen 518115,China
