Low voltage circuit breaker maintenance and operation
Effects of low voltage circuit breaker life in addition to the above reasons, there are the following factors: the use of time is too long, causing the breaker insulation aging; because intergroup wear and circuit breaker lubricating oil dries up, making it the open-close operation obstacles, movement characteristics change; due to overcurrent ( especially short circuit current ) breaking, in a dynamic and static contact is produced between the corrosive gases and impurities, so that the contact resistance is increased; as the ambient air temperature and circuit breaker after electrifying its heating, so that the insulating parts thermal deformation, to body movement brings the hindrance; because the connection terminal and other parts of the fastening screws and other relaxation, caused by abnormal heating, and even sparked. These factors are not independent, and often is on circuit breaker impact, which shortens the service life of the circuit breaker.
Circuit breaker inspection, for large frame circuit breaker such as DW17, in addition to finalize the design type test, production factory regular test, also can refer to several:
One, the use of electricity before the examination
Check the transportation circuit breaker box, should not have the scraps of paper or the dust attached on the circuit breaker; inspect the wire connection; examination of pressure performance and some other basic situation, ensure there is no problem.
Two, regular inspection
Low voltage circuit breaker based on the use of the environment and working conditions, it is necessary to carry out periodic periodic inspection, pay attention to dust, cleaning work.
In three, low voltage circuit breaker internal inspection matters needing attention
When the need to open the cover check the circuit breaker body and contact system, due to the internal circuit breaker insulating barrier, interrupter and easy to fall off, thus opening the cover after the examination, must be counted, to easily drop parts one one restoration, for small frame size current circuit breaker, such as the common DZ47-63, DZ47-100 leakage circuit breakers. The bottom and the cover affixed with a seal ( or warning sign ), is not to let any of the release element to be adjusted, therefore, special attention should be paid not to touch the trigger element, otherwise the performance change, factory is not responsible.
Four, about short circuit after the circuit breaker inspection matters and processing method
When the circuit breaker is in general in short circuit, the current breaking is often small dry line expected short-circuit current value ( i.e. less than circuit breaker ultimate short-circuit breaking current). This is due to a short circuit and a power supply distance, short circuit impedance and circuit breakers rated voltage and the actual line voltage compared to a certain amount of differences.
For less than circuit breaker ( such as circuit breaker DZ47LE ) rated short-circuit breaking capacity of short circuit current, after breaking, can still use. However, if the disconnection is rated ultimate short-circuit current or take cascade ( reserve) to protect the bad conditions of the breaking, then the circuit breaker damage mostly. Running short circuit breaking in the actual operation, when breaking short circuit current, short circuit accidents excluded, there needs to be a circuit breaker reclosing of ( even breaking rated short-circuit current ), just after breaking the same value of short circuit current, circuit breaker must be replaced.
The above data of electrical switch factory provide for reference purposes only ( www.jiandq.com )