SF6 circuit breaker is a new type of high-voltage electrical switchgear, widely used in power systems due to its excellent performance, reliability, ease of maintenance, and durability. However, many people still lack understanding of the core components of SF6 circuit breakers, such asSF6 gas density meter and density relay. This not only increases the difficulty of assembly and maintenance, but also may affect the quality of work and misunderstand the normal state of the equipment.
Role of SF6 Gas Density Meter
Density refers to the mass of a substance per unit area under specific conditions. The SF6 gas in SF6 circuit breakers is enclosed in a fixed container. Under the rated pressure after 20°C, it has a certain density value. Within the allowable range of various operating conditions of the circuit breaker, although the pressure of SF6 gas changes with temperature, the density value of SF6 gas remains constant. Since the insulation and arc extinguishing characteristics of SF6 circuit breakers mainly depend on the purity and density of SF6 gas, it is important to monitor the purity and density of SF6 gas. When using a general pressure gauge to monitor the leakage of SF6 gas, it is difficult to distinguish whether there is a real leakage or the pressure changes due to environmental temperature. In order to achieve routine monitoring of density, national industry standards require the installation of pressure gauges orSF6 gas density meters and density relays on SF6 circuit breakers. Pressure gauges orSF6 gas density meters are used for monitoring, while density relays are used for control and buffering.
Structure and Principle of SF6 Gas Density Meter
The SF6 gas density meter installed on the SF6 circuit breaker is called a density meter when it has a needle and a scale; it is called a density electromagnetic valve or density pressure power switch when it does not have a needle or a scale; someSF6 gas density meters also have electrical contact points, which are used as density electromagnetic valves. They are used to accurately measure SF6 gas.
The Structure of SF6 Gas Density Meter
The structure of the SF6 gas density meter mainly consists of spring metal bellows, gear mechanism, dial, and double steel strip. The spring metal bellows is connected to the circuit breaker, and its internal space is in communication with the SF6 gas in the circuit breaker. The top of the spring metal bellows is connected to wear-resistant steel strips that play a role in temperature compensation, and the double steel strips are connected to the gear mechanism and dial with screws.
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