Electrical Control System Failures of Passenger Elevator
Judging from the range of electrical failures in passenger elevators, the most common ones are caused by faults in the door machine system and poor electrical component contact. Caused by the door machine system and electrical components many reasons for failure, mainly the quality of components, the quality of installation and commissioning, maintenance and quality.
From the nature of electrical faults, it is mainly short circuit and open circuit. The short circuit is due to some reason, and the resistance in the line after the circuit that is not supposed to be connected is connected or turned on is very small. Causes of common short circuit faults in elevators are mechanical and electronic interlocking failures of direction contactors or relays, which may cause a contactor or relay to rush and cause a short circuit; when the main contact of a contactor is turned on or off, the resulting arc causes the surrounding dielectric The medium of the component is broken down and short-circuited; the insulating material of the electrical component deteriorates due to aging, failure, and moisture; the electrical component of the electrical component is destroyed due to external reasons and the external material is invaded to cause a short circuit.
The disconnection is due to some reason, causing the circuit that should be connected to fail. Causes of disconnection are mainly caused by loosening of lead wires introduced into the electrical components; welding of the circuit as a connecting point; or defective welding; contacts of relays or contactors are burned by the arc; contact surfaces are covered by an oxide layer; contact reeds are connected or When the arc is disconnected, it will lose its elastic force after cooling, causing the contact pressure of the contact point to be insufficient. When the relay or the contactor is engaged or disconnected, the contacts will be in poor contact due to the vibration.
Judgment and elimination of electrical control system faults. The basis for judging the fault of the electrical control system is the passenger elevator control principle. Therefore, to quickly eliminate the fault must master the circuit diagram of the regional control system, to understand the elevator from the orientation, start, acceleration, full-speed operation, arrival forecast, speed change, leveling, switching door and other aspects of the whole process of the process, The mutual control relationships among various electrical components, the functions of various electrical components, relays/contactors and their contacts.
Before judging the failure of the passenger elevator's electrical control, it is necessary to thoroughly understand the fault phenomenon and to quickly and accurately analyze the cause of the fault and find the fault point according to the circuit diagram and the fault phenomenon.