An accident analysis caused by a secondary circuit connection wrong;

Faults frequently found in secondary circuit of circuit breaker and improvements;

The methods of looking up the fault of secondary circuit;

Analysis of voltage transformer secondary loop grounding point;

Secondary loop includes current transformer,voltage transformer,secondary wiring,electronic energy meter and burden monitoring units.

In view of occasional erroneous wiring of current often met with in the power industry, the paper discusses the mutual influence among different parameters of current transformers, as well as the effect of erroneous wiring of transformer terminals on the secondary loop current, on secondary load impedance and an the reliability of protection by relays.

The water quality control in PWR secondary system has close relationship with the service life of key important components,such as SG.

A real time model of simulation of secondary system for PWR nuclear power unit is presented.

model of the general second-order circuits.

Discussion on the second-class highway design common fault

Based on the theory of the vehicle moving stability,the effects of beyond-standard second-class highway in the mountains on traffic safety are analyzed,and some improving measures of our safety guarantee engineering are proposed.

Based on the summary of the common failure of the similar bridge abutment in the second-class highway of Yongbin stage in the National Route 322,the author analyzes the concrete cause of the failure,puts forward the rational reinforcement treatment scheme,the observation proves that the treatment scheme obtains the good effect,the problems are basically solved.