What is the protection mechanism of Power Cabinet under overload and short circuit conditions?
Publish Time: 2024-07-04
The protection mechanism of Power Cabinet under overload and short circuit conditions is a key link to ensure the stable operation of the power system and the safety of equipment. The following is a brief introduction to the protection mechanism in these two situations:
1. Overload protection mechanism
Overload means that the current in the Power Cabinet exceeds the rated current value that the equipment can withstand. Long-term overload may cause equipment damage. In order to deal with this problem, Power Cabinet usually adopts the following overload protection mechanisms:
Thermal relay protection: The thermal relay is an overload protection device based on the relationship between current and time. When the current exceeds the rated value, the resistor inside the thermal relay will heat up. After the temperature rises, the relay will be triggered to cut off the circuit, thereby protecting the equipment from damage. This protection mechanism has the characteristics of high reliability and good sensitivity.
Electronic circuit breaker protection: The electronic circuit breaker is an intelligent overload protection device that uses electronic technology to achieve overload protection of the circuit. When the current is detected to exceed the set value, the electronic circuit breaker will quickly cut off the circuit to prevent damage to the equipment. Compared with traditional thermal relays, electronic circuit breakers have higher accuracy and faster response speed.
2. Short-circuit protection mechanism
Short circuit refers to the current in the circuit bypassing normal resistance, inductance and other components, directly forming a short-circuit path, causing the current to increase sharply. The main purpose of the short-circuit protection mechanism is to quickly cut off the circuit when a short circuit occurs to prevent serious consequences such as equipment damage and fire. Common short-circuit protection mechanisms include:
Fuse protection: The fuse is equipped with fusible alloy or metal wire. When a short circuit occurs in the circuit, the short-circuit current causes the fuse to melt quickly and cut off the circuit. Fuses have the advantages of simple structure, low price and easy use, and are commonly used devices in short-circuit protection.
Short-circuit protection relay: The short-circuit protection relay determines whether a short circuit occurs by detecting the change in current. When the current exceeds the set value, the relay will act quickly to cut off the circuit. This protection mechanism can protect the circuit more accurately and prevent false operation.
In summary, Power Cabinet uses multiple protection mechanisms such as thermal relays, electronic circuit breakers, fuses and short-circuit protection relays to ensure the stable operation of the power system and the safety of equipment in overload and short-circuit conditions. These protection mechanisms need to be selected and configured according to specific needs during design and application to achieve the best protection effect.
