PV fuses Full-time Job2022-06-10 09:29 Engineering Darzāb 41 views
PV fuses are utilised to protect solar power gathering equipment against overcurrents, reserse currents and short circuits that can occur within alternative energy gathering PV string installations. Photovoltaic (PV) fuses vary in a number of different ways including fuse speed, voltage and amperage rating, breaking capacity and their physical size and shape. Photovoltaic fuses have the following superior properties: 1. Comprehensive protection: PV fuses can effectively break down to 1000Vdc. Especially suitable for thin film batteries and 4", 5", 6" crystalline silicon panels; 2. Environmental protection and recyclable: Photovoltaic fuses fully consider the operation of the photovoltaic panel system and the environmental impact; 3. 1000Vdc capacity: Photovoltaic fuses are suitable for typical photovoltaic panel systems, operating conditions can reach 1000Vdc, and the fusing response time is less than 1ms; 4. 10×38mm international standard specification: suitable for various current ranges, there are standard metal ferrules, bolts and multi-purpose circuit board mounting methods to choose from.
In electronics and electrical engineering, a fuse is an electrical safety device that operates to provide overcurrent protection of an electrical circuit. Its essential component is a metal wire or strip that melts when too much current flows through it, thereby stopping or interrupting the current. It is a sacrificial device; once a fuse has operated it is an open circuit, and must be replaced or rewired, depending on its type. Fuses have been used as essential safety devices from the early days of electrical engineering. Today there are thousands of different fuse designs which have specific current and voltage ratings, breaking capacity, and response times, depending on the application. The time and current operating characteristics of fuses are chosen to provide adequate protection without needless interruption. Wiring regulations usually define a maximum fuse current rating for particular circuits. Short circuits, overloading, mismatched loads, or device failure are the prime or some of the reasons for fuse operation. When a damaged live wire makes contact with a metal case that is connected to ground, a short circuit will form and the fuse will melt. A fuse is an automatic means of removing power from a faulty system; often abbreviated to ADS (Automatic Disconnection of Supply). Circuit breakers can be used as an alternative to fuses, but have significantly different characteristics. This is a cylindrical fuse. When the circuit fails or is abnormal, the current continues to rise, and the increased current may damage some important components in the circuit, or may burn the circuit or even cause a fire. If the fuse is correctly placed in the circuit, the fuse will cut off the current by itself when the current abnormally rises to a certain height and heat, thus protecting the safe operation of the circuit.
High speed fuse is a type of fuse, which is mainly used for short-circuit protection of semiconductor rectifier components or rectifier devices. Since the overload capacity of semiconductor components is very low, they can only withstand large overload currents in a very short period of time, so short-circuit protection is required to have the ability to quickly fuse. The structure of the high speed fuse is basically the same as that of the enclosed fuse with filler, but the melt material and shape are different. It is a variable-section melt with a V-shaped deep groove punched by a silver sheet. In addition to a metal wire with a certain shape, the fuse of the quick-acting fuse will also have a solder joint of a certain material on it, the purpose of which is to make the fuse disconnect quickly under overload conditions. The melt of the high speed fuse is made of pure silver. Due to the low resistivity, good ductility and good chemical stability of pure silver, the melt of the high speed fuse can be made into thin sheets and has a round hole and narrow neck structure. When a short-circuit fault occurs, the current density at the narrow neck is large, so the narrow neck is first fused and divided into many small sections by quartz sand. In this way, the arc formed by the melting of the melt is divided into many small sections by the quartz sand, the arc current is small, the distribution space is small, and it is easily absorbed by the arc extinguishing agent. And because the quartz sand is insulating, an insulator is formed immediately after the arc is extinguished to break the circuit.
NH fuses (also known as NH Knife Blade Fuses or DIN NH Blade Fuses) were defined in the German DIN standard 43620 around 1944. They were primarily designed as general purpose fuses for the protection of conductors. NH fuses are one-time fuses, meaning once they have blown, they must be replaced with a new fuse with the same characteristics. NH fuses are constructed from a rectangular ceramic casing enclosed by a cover plate that features a metal blade style terminal on each end. The fuse element inside the casing is connected to the cover plate / blade terminals. The majority of NH Fuses have a trip indicator to show if the fuse element has blown. Each cover plate includes a metal extraction lug that enables quick removal of the fuse from a holder when using the recomended NH fuse puller tool. NH Fuses have evolved over the years to suit a wide range of applications. NH fuse bases feature a thermoplastic base, which is highly temperature resistant and made from self-extinguishing material. Each base has 2 silver plated copper clips that provide a firm contact to the metal blades of the fuse. Electrical cables are connected to the metal studs on the base and secured by a nut and spring washer. The NH bases are sold as open air units, however, optional protection kits are available to ensure that fingers do not come into contact with electricity flowing through the fuse and base. These kits include clip-on phase barriers, terminal shrouds and fuse covers. When fully assembled, the fuse and holder is completely enclosed to achieve an IP 20 protection rating. NH fuse bases can be surface mounted by using several screws or bolts to secure the Nh fuse base(s) to a panel. Some models are also designed for mounting on a DIN rail. Be careful when buying an NH fuse base to ensure it meets your mounting requirement.
Wind energy fuse can be seen from the literal meaning, is the wind power generation circuit system, play the role of electrical equipment to protect the circuit. When the current abnormally increases to a certain height and heat, its own fuse cut off the current, to protect the safe operation of the circuit. When an electric current flows through a conductor, there is some resistance in the conductor, so the conductor will heat up. The size of the current and resistance to determine the speed of heat generation fuse construction and installation of the condition determines the speed of heat dissipation, if the speed of heat generation is less than the speed of heat dissipation, the fuse is not fused. If the rate at which heat is generated equals the rate at which heat is dissipated, it will not fuse for a considerable time. If the rate at which heat is produced is greater than the rate at which heat is dissipated, then more and more heat is produced. Because it has certain specific heat and mass again, the increase of its heat goes up with respect to the performance in temperature, the fuse occurred when the temperature rises to the melting point of fuse above.