A, product application: 
 The substation DC feed network in a tree structure, electrical equipment from the battery arrival, usually after three distribution for each level distribution most of the DC circuit breaker as protection of electrical Protect the operating characteristics of the upper and lower DC circuit breaker does not match the grade trip, often caused by a lower electrical equipment short-circuit fault on a DC circuit breaker in the DC system is running, causing the power outages of feeder lines accident, thereby causing the first substation equipment such as high-voltage switchgear, transformers, capacitors and other accidents. To prevent the DC circuit breaker and DC protection of electrical operating characteristics do not match the potential threat, the State Grid Corporation of DC protection for newly installed and running electrical appliances, provisions must conduct safety second characteristic test, to ensure consistent performance and design, to ensure that DC loop steps with correctness. DC power system operation specifications ", 2005, Article 12, paragraph 8 provides that" the DC fuses and air circuit breakers should be of acceptable quality products, fuse or value in accordance with relevant provisions of hierarchical configuration and tuning, and be checked regularly to prevent because it is not the correct action to expand the accident "; DC power system supervision requirements stipulated in Article 27:" ... automatic air circuit breaker characteristics and action current checks should be carried out before ... "; The prevention of DC power system accident measures "in Article XI provides that:" ... seconds of safety features and operating current sampling should be conducted prior to use ... ". This instrument is an essential tool for field testing and to determine the DC circuit breaker protection features are normal! 
 Second characteristic of DC protection of electrical safety in general in the national laboratory or inspection station test equipment covers an area of ??need to configure a special charging device and the large current load box and complicated to operate; part of the operating unit substation batteries for DC protection electrical differential meet the test, but can not accurately test the features of current - operating time. Resulting in the DC system is put into operation, field service maintenance personnel do not have the appropriate testing methods and tools can not test the second characteristic of the DC protection of electrical safety to meet the requirements. 
 DC protection of electrical safety second characteristic test of the actual situation, the company introduced a suitable substation site, easy to carry a high degree of automation of the DC circuit breaker An seconds characteristic test system for the operation and maintenance departments to provide DC protection of electrical operating characteristics the means test, the operating characteristics of the DC electrical protection and the differential with the check, in order to improve the reliability of operation of the DC system, to ensure safe and reliable operation of the grid. 
 This test system is suitable for the rated current of 1A ~ 500A DC circuit breaker safety seconds characteristic test can be used to 6A to 100A DC fuse safety second characteristic test. 

 Second, the product features 
 ◆ automatic measurement in a variety of current circuit breaker tripping time; 
 ◆ equipment with self-protection features to ensure the safety and reliability of the testing process; 
 ◆ micro-controller technology, breaking characteristics of the DC circuit breaker testing, measurement accuracy; 
 ◆ automatically generate a steady DC current output according to the requirements of fast response time; 
 ◆ advanced test technologies, high-precision test of the circuit breaker breaking time, the measurement accuracy of up to 0.1ms 
 Automatically draw the circuit breaker protection characteristic curve (A second curve); 
 ◆ statistical analysis capabilities, the print data reports, and characteristic curves 
 ◆ online with a laptop-site operations; 

 Third, the technical requirements 
 A), characteristics and main function 
 Automatic testing, the device 1, press Menu to complete a variety of test functions. 
 2, the host system using the new high-speed microprocessors and LSI, high reliability and excellent performance. 
 3, comes with large-screen graphics (320 x 240 dots) LCD, the whole Chinese graphical interface, easy to operate, easy to use. 
 4, the device automatically generates a constant high-current, high precision constant current, load capacity, a long time to provide a stable current. 
 5, can carry any current DC circuit breaker protective properties of the test. 
 6, the circuit breaker cascade testing. 
 7, can be accessed by computer, by computer-controlled operation. 
 8, can be recorded to save the test records of the last 100 of the protection features, for at any time, the recorded data can also be uploaded to the computer. 

 B) the main technical indicators 
 1 power supply: AC 220V ± 15% of 
 2, the maximum output current: DC 500A (expandable to 1000A or greater) 
 3, the output power stability: 0.5% 
 4, the current adjustment range 0-500A (1000A) 
 5, the current output Response time: 5ms 
 6, test methods: automatic time adjust the amount of precision: 1ms 
 7, display: - Graphics (LCD)