Common faults in electrical control systems

Update:22-01-2019
Summary:

1. From the scope of the electrical failure of the Hydr […]

1. From the scope of the electrical failure of the Hydraulic elevator, the most common is the failure of the door system and the poor contact of the electrical components. The reasons for the many failures of the door machine system and electrical components are mainly the quality of components, the quality of installation and commissioning, and the quality of maintenance.

2, from the nature of electrical faults, mainly short-circuit and open circuit two categories.
The short circuit is for some reason, the resistance in the line is small after the circuit that is not to be connected is connected or turned on. Common short-circuit faults in elevators have mechanical and electronic interlocking failures of directional contactors or relays, which may cause short-circuits caused by contactors or relays; when the main contacts of contactors are turned on or off, the resulting arc causes surrounding dielectric appliances The medium of the component is broken down and short-circuited; the insulating material of the electrical component is deteriorated due to aging, failure, and moisture; the dielectric breakdown of the electrical component due to external factors and the invasion of the external material cause a short circuit.

The disconnection is due to some reason, causing the loop that should be connected to be unreachable.
The cause of the open circuit is mainly due to the loosening of the lead wire of the electrical component;
Weld welding or poor contact as a connection point in the circuit;
The contact of the relay or contactor is burned by the arc; the surface of the contact is made of an oxide layer;
When the reed of the contact is turned on or off, the arc is heated, and the elastic force is lost after cooling, which causes the contact pressure of the contact to be insufficient; when the relay or the contactor is closed or disconnected, the contact of the contact is poor due to the jitter.