About breaker application's views and recommendations

 In recent years, railway signaling equipment used by the fuse tube fuse unit, double fuse breaker development. Because of the circuit breaker and mounting position using standard criteria has not explicitly, to the use of circuit breakers brought a lot of problems.
A signaling device uses the origin of the circuit breakerIn the early 1990s,"four off a red" once the signaling equipment in daily use in affecting transportefficiency and safety of inertia failure, irregular broken wires and fuses in the "four off a red" account for a large proportion of . To reduce such failures, once a single dual-fuse to replace the fuse, and in the mid-1990s, the standard line safety recommendations, the double standard building line fuse included. But in the process of promoting the use of the actual site, the fuse broken wire fault and no significant reduction in the failure rate remains high.
For the following reasons:
(1) can not afford the high current dual-fuse the moment of the impact of interference, often after a broken wire in the main fuse, secondary fuse is blown almost simultaneously.
(2) The blown fuse capacity is difficult to control, the same size, the same batch of products fuse melting current discrete greatly.
(3) No blown fuse current value of the means test, when fusing current measured value, the fuse will be scrapped.
(4) In the case of no current, can not be converted to the secondary fuse, such as the double turnout starting circuit fuse.
(5) Two fuses are not usually checked sub-fuse.
Therefore, in the year 2000, from the power station screen in some of the tests used to replace the fuse breaker, and on this basis, developed to zero in the composite layer and the side frame circuit breakers are used. For decades, a large number of performance and stability of the circuit breaker in the input signal power, signal power screen, the combination of frame zero layer and side, automatic block equipment, outdoor track transformer tank so widely applied, for substantial reduction fuse There are non-normal fuse failure played a significant role.
Two circuit breakers in the field use conditions
Breaker since the early 1990s into the Chinese railway market, according to statistics there are about more than 480 ten thousand in railway signal equipment used, in good condition overall use, failure rate of only one hundred thousandth, far lower than other signaling equipment failure rate.
Were classified as:
○ 1 unknown impact of interference caused by high current circuit breaker tripping;
○ 2 due breaker terminals (including the base terminal) loose, causing the output is not normal;
○ 3 Breaker Capacity choose too small, resulting in non-normal tripping;
○ 4 breaker burning.
3 Suggestions
(1) As the sixth largest railway speed and speed of 200 ~ 250km EMU CDB, continued normal use of the signal equipment brought unprecedented pressure. "Zero fault" maintenance philosophy is required signaling equipment with high feasibility. To this end, we must grasp three quality of the source, ie the source of the signal quality of products, quality of the source signal design and construction quality of the signal source.
(2) design department should be based on the use of a variety of signal device current value and the maximum fault current value, according to the circuit breaker is used to determine the Electric energy  characteristics of the circuit breaker capacity, rather than simply replace the circuit breaker with the same capacity fuse tube .
(3) According to various signaling equipment characteristics are used to determine the delay characteristics of the circuit breaker, ie what equipment required quick disconnect, and what equipment requires a short delay, the delay or latency.
(4) According to the characteristics of a variety of signaling equipment to determine the circuit breaker is installed. If the signal isolation transformer outdoor short circuit will cause the indoor breaker side current surge, so you must install the indoor side signal isolation transformer breaker. Another example is the rectifier circuit breaker installed in addition to the outer sides of the bridge diode circuit breaker must be installed, otherwise once the diode breakdown, will cause current surges, heating and even fire.
According to foreign sources, the circuit breaker in a variety of industries, including railway transport is widely used, but in the important electronic device, use a small fuse in series with the circuit breaker to protect the electronic equipment of poor resistance to flow, and in the anti- flow better performance relay equipment is extensive use of circuit breakers. China's railway industry can refer to this principle fuse settings.
(5) construction units should be based on the requirements and design department breaker manufacturer's installation process required for construction, construction quality to prevent malfunction caused the circuit breaker.