NEWS

Why can't the fuse be replaced with copper wire

Although a fuse is also a metal wire, it is different from ordinary copper and iron wires. It is soft and made of lead, antimony, or low melting point alloys such as lead and tin. Its resistivity is relatively large, the melting point is relatively low, and it is inherently afraid of heat. Due to the thermal effect of the current, as long as the current passing through the fuse exceeds the rated current of the fuse and reaches the fusing current, the fuse will quickly fuse and automatically disconnect the circuit from the power supply. In this way, the strong current can no longer enter the user's home, thereby preventing the meters, electrical appliances or wires connected to the circuit from being burned out due to excessive current. The fuse is broken and cannot be replaced with copper wire or iron wire. If copper wire or iron wire is used instead of fuse, because of their high melting point, even when a strong current passes, it will not be blown, and the purpose of automatically cutting off the current will not be achieved, and it will not play the role of insurance, which is very dangerous. In addition, when installing the fuse, you must pay attention to choosing the appropriate thickness. There are many specifications of fuses, usually expressed by its rated current. For fuses of the same material, the larger the cross-sectional diameter, the larger the rated current allowed to pass. Therefore, when choosing, you must first calculate the maximum working current through the circuit according to the total wattage of the electrical appliance, so that the rated current of the fuse is equal to or slightly greater than the maximum working current of the circuit. In this way, it is not only ensured that the fuse can work normally, but also that the fuse can be quickly blown to cut off the circuit when it encounters an excessive current. If the rated current of the fuse is too large, when there is an excessive current in the circuit, it will not be blown, and it will not play the role of insurance, which is no different from connecting steel wires and iron wires; In the case of electricity, the fuse will also blow, causing a power outage.

30

2020

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07

Longde Science: The role of thermal fuses in circuits

Thermal fuse, also known as thermal fuse, is a new type of electrical overheating protection element. This kind of component is usually installed in electrical appliances that are prone to heat. Once the electrical appliance fails and generates heat, when the temperature exceeds the abnormal temperature, the thermal fuse will automatically fuse, cut off the power supply, and prevent the electrical appliance from causing a fire. In recent years, most of the household electrical appliances with heating as the main function in our country, such as electric rice cookers, electricity bills, electric stoves, etc., are mostly equipped with thermal fuses, which can cut off the power in time when the internal parts of the machine fail to prevent further electrical appliances. Damage, but also put an end to the resulting fire. The thermal fuse is the same as the fuse we are familiar with. It is usually only used as a power supply path on the circuit. If it does not exceed its rated value during use, it will not be blown and will not have any effect on the circuit. Only when the appliance fails and produces abnormal temperatures, it will fuse and cut off the power circuit. This is different from fuse fuses, which are blown by the heat generated when the rated current is exceeded in the circuit. Thermal fuses have the characteristics of accurate fusing temperature, high withstand voltage, small size and low cost. The rated temperature value and rated current value are marked on the shell of the thermal fuse, which is easy to identify and very convenient to use. It can be widely used in electrical equipment, electric heating equipment and practical electrical appliances for overheat protection. The thermal fuse mainly has the following parameters: ①Rated temperature: sometimes called operating temperature or fusing temperature, it refers to the temperature at which the temperature rises at a rate of 1°C per minute to fusing temperature under no load. ②Fusing accuracy: refers to the difference between the actual fusing temperature and the rated temperature of the thermal fuse. ③ Rated current and rated voltage: The nominal current and voltage of the general thermal fuse have a certain margin, usually 5A and 250V. The thermal fuse is a one-time-use protection component, and its use effect depends not only on the performance of the component itself, but also on how to correctly select and install the thermal fuse. When the thermal fuse is used, it is generally connected in series in the circuit. Therefore, when selecting the thermal fuse, the rated current value must be greater than the current used in the circuit, and the current through the thermal fuse is never allowed to exceed the specified rated current value. Before selecting the rated temperature of the thermal fuse, it is necessary to know and actually measure the temperature difference between the temperature that needs to be protected and the location where the fuse is installed. In addition, the length of the fusing time and the availability of ventilation are also closely related to the selection of the rated temperature of the thermal fuse.

30

2020

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07

How to use the thermostat to achieve real energy saving

Under the advocacy of "coal-to-electricity" for clean heating in the country, more and more households use electric heating, and how to save energy has become a problem that many people pay attention to. In addition to good house insulation, temperature control is one of the keys to energy saving. Some users who have installed electric heating will always turn on the thermostat when needed, and turn off the thermostat when they go out, thinking that this will save electricity. In fact, this will not only save energy, but will consume more energy. So how to use the thermostat to achieve real energy saving?     Myth 1. Is it possible to save energy when you use it right away?   Turn on the thermostat when you need it and turn it off when you go out, which consumes energy. An electric heating system is a system that operates at low temperatures. Has good heat storage. After the system is turned on, it takes a certain amount of time for the room temperature to reach the set temperature, while the indoor temperature will not drop rapidly after the system is turned off. When it is turned on again, it also takes a longer time to make the temperature rise again. Frequent switching not only fails to save energy, but also increases the operating cost of the heating system.   Correct use method: The temperature of the room that is not frequently used can be lowered by a few degrees through the thermostat. When you leave the house for a long time, you only need to lower the temperature of the thermostat by a few degrees. You can choose to turn off the system when you don’t live for a long time or leave for a long time. , but it should be noted that if there is equipment in the room that is afraid of freezing, it should be turned on to a certain temperature to prevent the equipment or pipes from freezing.         Misunderstanding 2. The higher the temperature set by the thermostat, the faster the temperature rises? Some users feel that the room temperature is low, and they need to set the temperature of the thermostat to the highest temperature if they need to heat up quickly. This approach is also wrong. The heating time of the room temperature depends on the indoor and outdoor temperature difference and the installed power per unit area of ​​the room. Under the condition that the installation power and the temperature difference between indoor and outdoor are certain, no matter how many degrees are set, the time for the room to rise to the temperature you need is the same. If the room is 16 degrees now, and you want the room to heat up to 18 degrees, in this case, set the room temperature to 18 degrees or 20 degrees, 25 degrees, and the time it takes to heat up to 18 degrees is the same.   Correct use method:   Set as many degrees as needed, or use an intelligent thermostat, the thermostat can automatically calculate the advance opening time of the thermostat.

30

2020

/

07

Talking about the role of thermal fuse

Thermal fuse, also known as thermal fuse, is a new type of electrical overheating protection element. This kind of component is usually installed in electrical appliances that are prone to heat. Once the electrical appliance fails and generates heat, when the temperature exceeds the abnormal temperature, the thermal fuse will automatically fuse, cut off the power supply, and prevent the electrical appliance from causing a fire. In recent years, most of the household electrical appliances with heating as the main function in our country, such as electric rice cookers, electricity bills, electric stoves, etc., are mostly equipped with thermal fuses, which can cut off the power in time when the internal parts of the machine fail to prevent further electrical appliances. Damage, but also put an end to the resulting fire. The thermal fuse is the same as the fuse we are familiar with. It is usually only used as a power supply path on the circuit. If it does not exceed its rated value during use, it will not be blown and will not have any effect on the circuit. Only when the appliance fails and produces abnormal temperatures, it will fuse and cut off the power circuit. This is different from fuse fuses, which are blown by the heat generated when the rated current is exceeded in the circuit.     Thermal fuses have the characteristics of accurate fusing temperature, high withstand voltage, small size and low cost. The rated temperature value and rated current value are marked on the shell of the thermal fuse, which is easy to identify and very convenient to use. It can be widely used in electrical equipment, electric heating equipment and practical electrical appliances for overheat protection. The thermal fuse mainly has the following parameters:   ①Rated temperature: sometimes called operating temperature or fusing temperature, it refers to the temperature at which the temperature rises at a rate of 1°C per minute to fusing temperature under no load. ②Fusing accuracy: refers to the difference between the actual fusing temperature and the rated temperature of the thermal fuse. ③ Rated current and rated voltage: The nominal current and voltage of the general thermal fuse have a certain margin, usually 5A and 250V.   The thermal fuse is a one-time-use protection component, and its use effect depends not only on the performance of the component itself, but also on how to correctly select and install the thermal fuse. When the thermal fuse is used, it is generally connected in series in the circuit. Therefore, when selecting the thermal fuse, the rated current value must be greater than the current used in the circuit, and the current through the thermal fuse is never allowed to exceed the specified rated current value. Before selecting the rated temperature of the thermal fuse, it is necessary to know and actually measure the temperature difference between the temperature that needs to be protected and the location where the fuse is installed. In addition, the length of the fusing time and the availability of ventilation are also closely related to the selection of the rated temperature of the thermal fuse.

30

2020

/

07

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