Protection configuration of distribution cabinet

　　The protection configuration of the distribution cabinet is to ensure the safe and stable operation of the electrical system, and to promptly cut off the power supply in case of faults or abnormalities, in order to prevent equipment damage or personnel injury. The following are common protection configurations in distribution cabinets:

　　1. Overload protection

　　Function: When the load in the circuit exceeds the rated current, it can cause electrical equipment to overheat, thereby damaging the equipment or causing a fire. The overload protection device can detect abnormal increases in current and automatically disconnect the circuit when the current exceeds the safe range.

　　Common devices: thermal relays, overload protectors, circuit breakers, etc. Circuit breakers can not only protect circuits from overload, but also manually or automatically reset them.

　　2. Short circuit protection

　　Function: Short circuit can cause instantaneous high current, which may cause serious damage to electrical equipment and circuits, and even trigger fires. Short circuit protection can quickly detect and cut off short-circuit circuits, preventing equipment damage.

　　Common devices: air circuit breakers, fuses, electronic protectors, etc. Air circuit breakers will immediately cut off the current when short circuited, while fuses protect equipment by melting the fuse.

　　3. Leakage protection

　　Function: Leakage protection is designed to prevent electric shock or equipment damage caused by equipment or wire leakage. When current flows out of the system through an unexpected path (such as through the human body), the leakage protection device will immediately cut off the power supply.

　　Common device: Leakage protection switch (RCD/RCBO), which can detect unbalanced current and quickly cut off the circuit when leakage is detected.

　　4. Overvoltage protection

　　Function: High voltage may cause insulation damage to equipment, damage to electronic components, and even trigger electrical fires. Overvoltage protection can cut off the power supply when the voltage exceeds the rated value, avoiding equipment damage caused by overvoltage.

　　Common devices: overvoltage protectors, electronic voltage protectors, voltage regulators, etc.

　　5. Undervoltage protection

　　Function: Low voltage can cause a decrease in motor speed, equipment malfunction, and even damage to the device. The undervoltage protection device can automatically cut off the power supply when the voltage is too low, preventing the equipment from working under unstable voltage.

　　Common devices: undervoltage relay or undervoltage circuit breaker. These devices can monitor voltage levels and operate when the voltage falls below a safe range.

　　6. Over temperature protection

　　Function: When the operating temperature of electrical components or systems is too high, it is easy to cause equipment damage or fire. Over temperature protection can cut off power or trigger an alarm when the temperature exceeds the set value.

　　Common devices: temperature control switch, temperature sensor, thermal relay, etc. The thermostat can monitor temperature changes to ensure that the equipment operates within a safe temperature range.

　　7. Phase sequence protection

　　Function: In a three-phase power system, if the phase sequence is connected incorrectly or there is a phase loss (loss of voltage in one phase), it can cause the motor to reverse or fail to work properly, thereby damaging the equipment. The phase sequence protection device can detect phase sequence errors or missing phases and stop equipment operation.

　　Common devices: phase sequence protection relays or phase sequence detectors, which can promptly detect phase sequence errors and take corresponding measures.

　　8. Lightning protection

　　Function: Lightning strikes may cause instantaneous high voltage surges in the power system, which can damage equipment or electrical circuits. Lightning protection can discharge the instantaneous high voltage generated by lightning to the ground, protecting equipment safety.

　　Common devices: lightning arrester, surge protection device (SPD). Surge protectors can protect electrical equipment from damage in the event of lightning or transient overvoltage in the power grid.

　　9. Grounding protection

　　Function: Grounding protection is the foundation of electrical system safety, which can prevent leakage accidents and protect equipment and personnel safety. In the event of a fault or leakage, the grounding system can safely guide the current to the ground, avoiding electric shock accidents.

　　Common devices: grounding wire, grounding rod, and protective grounding terminal. The metal casing of the distribution cabinet should be reliably connected to the grounding system to ensure that any leakage can be effectively conducted to the ground.

　　10. Isolation protection

　　Function: Isolation protection is to prevent electrical interference between high-voltage and low-voltage systems. By using isolation devices, ensure the safe and independent operation of different voltage systems, and avoid damage from high voltage to low voltage equipment.

　　Common devices: isolation switches, isolation transformers, etc. These devices can isolate high-voltage circuits when needed, ensuring safety during operation and maintenance.

　　11. Current protection

　　Function: Current protection can monitor the operating current of electrical equipment. When the current exceeds the set value, the system will automatically cut off the power supply, protecting the equipment from damage caused by current impact.

　　Common devices: current relay, current protector. They can automatically protect according to the set current value.

　　12. Time protection

　　Function: Time protection is the protection of electrical equipment within a specific time period, such as start-up delay or short circuit protection delay, to prevent momentary current surges from causing misoperation or equipment damage.

　　Common device: time relay. It can delay the action after the current or voltage reaches the critical value according to the preset time parameters, ensuring system safety.

　　13. Remote monitoring and alarm

　　Function: The remote monitoring function of the distribution cabinet can monitor the real-time operation status of equipment, such as temperature, voltage, current, load, etc. When a malfunction occurs, the alarm system will alert the operator through sound and light alarms or remote notifications.

　　Common devices: remote monitoring module, alarm, communication module (such as Ethernet, GPRS, 4G, etc.), which can achieve remote management and fault warning of distribution cabinets.

　　Summary

　　The protection configuration of the distribution cabinet covers multiple aspects such as current, voltage, temperature, phase sequence, and leakage, aiming to ensure the safe operation of the system and avoid equipment damage and personal injury. High quality distribution cabinets will select suitable protective devices based on application scenarios and requirements, and configure them reasonably to achieve appropriate protection effects.