This case is the most frequently occurring failure, after a long time, there may be generally like electrical switching line is connected, can lead to poor contact with the contact line ; there is a situation that is not good quality wire, broken internal situation that may arise, leading to time off on the circuit. In such case, the fastening occurs a switch or rewiring.
This generally does not appear in the high voltage cables, the case can only be seen in the weak line . In digital circuits and, under certain circumstances conditions, the fault will be presented, there may indeed be too much interference so that an error affecting the control system, but also individual elements of the circuit board or the overall performance parameter parameter has changed, anti-jamming the ability to tend to the critical point, and thus failure.
This occurs in summer or winter peak, home electrical products substantially open 10 hours one day, if the heat is not is good, the air temperature rises to switch itself can not bear, overheating tripping occurs.
This occurs typically air leakage switch or switch current is too small, the electrical equipment load power is large, the use of the switching current exceeds rated current, it will frequently trip.
If there is moisture, dust on the electrical wiring or other electrical equipment or electrical equipment lines, moisture and dust will be conductive, having a resistance effect, and in the process the thermal expansion and contraction will change the resistance, the resistance value in conjunction with a parallel effect of other elements, the circuit parameters will change when this effect is stronger, so that malfunction.
Basically common cause of good times and bad is more than a few reasons for the switch, if your home electrical switches also appear good times and bad, the situation can be analyzed to identify failures.