Common Faults and Problems of Terminal Blocks
From the perspective of use, the function that the terminal block should achieve is: the place where the contact part should be conducted must be conducted, and the contact is reliable. The place where the insulation part should not be connected must be insulated reliably. There are three common forms of fatal faults in terminal blocks:
1. The problem of poor contact
The metal conductor inside the terminal block is the core part of the terminal, which transmits the voltage, current or signal from the external wire or cable to the corresponding contact of the matching connector. Therefore, the contact must have an excellent structure, stable and reliable contact retention and good electrical conductivity. Due to the unreasonable structural design of the contact piece, wrong material selection, unstable mold, out-of-tolerance processing size, rough surface, unreasonable surface treatment process such as heat treatment and electroplating, improper assembly, harsh storage and use environment and improper operation and use, all of them will be damaged in the contact piece. The contact part and the mating part cause poor contact.
2. The problem of poor insulation
The role of the insulator is to keep the contacts in the correct position, and to insulate between the contacts and between the contacts and the housing. Therefore, the insulation must have excellent electrical properties, mechanical properties and process forming properties. Especially with the widespread use of high-density and miniaturized terminals, the effective wall thickness of the insulator is getting thinner and thinner. This puts forward more stringent requirements on insulating materials, injection mold precision and molding process. Due to the presence of excess metal on the surface or inside of the insulator, surface dust, flux and other pollution, organic material precipitates and harmful gases, the adsorption film fuses with the surface water film to form an ionic conductive channel, moisture absorption, mold growth, and aging of insulating materials. Will cause short circuit, leakage, breakdown, low insulation resistance and other poor insulation.
3. Fixed bad issues
The insulator not only plays an insulating role, but also usually provides precise centering and protection for the protruding contacts, and also has the functions of installation positioning, locking and fixing on the device. Poor fixation will affect the reliability of contact in the slightest and cause instantaneous power failure, and the serious one will be the disintegration of the product. Disintegration refers to the abnormal separation between the plug and the socket, between the pin and the socket caused by the unreliable structure of the terminal due to the material, design, process and other reasons in the mated state, which will cause the power transmission of the control system and Serious consequences of interruption of signal control. Due to unreliable design, wrong material selection, improper selection of molding process, poor quality of heat treatment, mold, assembly, welding and other processes, improper assembly, etc. will cause poor fixation.
In addition, the appearance is poor due to plating peeling, corrosion, bruises, molded case flashes, cracks, rough processing of contacts, deformation, etc., due to the out-of-tolerance positioning and locking fit dimensions, poor processing quality consistency, and excessive total separation force. Poor interchange caused by large and other reasons is also a common disease and frequently-occurring disease. These kinds of faults can generally be found and eliminated in time during inspection and use.
