Fuses on XL-21 Switchgear

 XL - 21 Switchgear is a common low - voltage power switchgear. The fuses on it play an important protective role in the circuit. The following is a detailed introduction to you from aspects such as functions, types, selection, installation and maintenance:

### FunctionsYouTube：https://youtube.com/shorts/c2JkuDaBHio
A fuse is a simple and effective protective electrical device. When an overload or short - circuit fault occurs in the circuit, the melt (fuse wire) in the fuse will melt due to the heat generated by excessive current, thus cutting off the circuit, preventing the further expansion of the fault, and protecting electrical equipment and lines from damage caused by over - current.

### Common Types
- **Porcelain plug - in fuse**: It has a simple structure and is inexpensive. It is often used for the protection of circuit branches with a small rated current, generally in circuits of small - power loads such as lighting.
- **Screw - in fuse**: It has a relatively strong breaking capacity and an obvious fusing indication. It is often used in machine tool electrical control circuits and the branch circuits of some power equipment.
- **Enclosed tube fuse with filler**: It has advantages such as high breaking capacity and good current - limiting characteristics. It is suitable for circuits with a large short - circuit current. In XL - 21 power cabinets, this type of fuse is often used to protect some high - capacity motors or important loads.

### Selection Key Points
- **Rated voltage**: The rated voltage of the fuse should not be lower than the working voltage of the circuit. For example, if the working voltage of the circuit is 380V, then the rated voltage of the fuse should be selected to be equal to or greater than 380V.
- **Rated current**: The appropriate rated current should be selected according to the magnitude of the load current in the circuit. For general lighting circuits, it can be selected at 1 - 1.2 times the rated current of the load. For motor circuits, considering the inrush current during motor startup, it is usually selected at 1.5 - 2.5 times the rated current of the motor.
- **Breaking capacity**: The breaking capacity refers to the maximum current value that the fuse can safely cut off the circuit under fault conditions such as short - circuits. A fuse with a corresponding breaking capacity should be selected according to the maximum possible short - circuit current in the circuit to ensure that the circuit can be reliably cut off when a fault occurs.

### Installation and Maintenance
- **Installation**: When installing the fuse, ensure that the melt has good contact with the clamp seat and is firmly connected to avoid overheating caused by poor contact, which may affect the normal operation of the fuse. At the same time, the installation position of the fuse should be convenient for inspection and replacement.
- **Maintenance**: Regularly check whether the appearance of the fuse is damaged, discolored, etc. If there are any abnormalities, it should be replaced in a timely manner. When replacing the melt, use a melt of the same specification as the original one. Do not arbitrarily increase the rated current of the melt to avoid losing the protective function.#Switchboard#power equipment#power box#switch box#electric substation#electrical substation#substations#power substation #transformer#Power transformer#step up transformer#step up transformers#power transformers#step-down transformer#electric vehicle charging station/电动汽车充电桩#circuit breaker#car charging#electric car charging stations#chargepoint/充电#ev charging stations#electrical switchgear#switchboards#electrical box#electrical boxes#russo power equipment#power equipment#electric#chargepoint charging station#chargepoint charger#step down transformer#dry type transformer#distribution substation#step up transformer#power box#Power transformer#Power transformers#low voltage switchgear#high voltage switchgear#Electrical Equipment#power equipment#power transfarmer#Power Substations#types of transformer#single phase transformer#three phase transformer#distribution transformer#transformer price#25 kva transformer price#25 kva transformer weight#220 kv substation#mobile transformer#100 kva transformer price#Pad mounted