Analyzes the startup procedure of gas combustion engine,combining with the practice of its turn-round,finds out its turn-round reasons after steam turbine tripping during startup,proposes solutions and presents treatment results.

By means of electron microscope analysis, chemical compsition analysis, mechanical test and metallurgical structure observation of thread tripping tubing in Daqing oil fields, we conclude that the tubing thread leaks when it can not seal properly.

The mechanism of casing tube s thread tripping is analyzed and the measures to prevent casing tube s thread tripping are proposed in this article.

Damage brought by canceling the under-voltage (no-voltage) release of low-voltage breaker and its solutions;

With the wide spreading of the electrical equipment application working under different frequencies,the primary factor affecting the circuit breaker electromagnetic release performance under different frequencies was discussed.

In operation process of the power plant,when the trip trouble happened in its main auxiliary units,its automatic control system can lower the load quickly and safely.

The article introduces the properties, data and under different use conditions, the design and material selection for bimetal elements, which can be as references for circuit breaker thermo-actuated tripper designers.