Learn about the 139 terminal block in one minute.

139 terminal block The plastic insulating materials and conductive parts are directly related to the quality of terminals; they respectively determine the terminal's insulation performance and conductivity. Any failure of a wiring terminal can lead to the failure of the entire system project. Prevention is the goal, and analysis is the foundation. In a sense, failure prevention is even more important than failure analysis, which holds significant practical implications for ensuring the quality and reliability of 139 wiring terminals.

139 terminal block

From a usage perspective, 139 terminal block The function should be as follows: The parts that need to be conductive must be conductive and reliably connected; the insulated parts, where conduction is not allowed, must be reliably insulated. The three common forms of fatal failures in 139 terminal blocks are as follows:

1. Poor contact. 139 terminal block The internal metal-ion conductor is a core component of the terminal. It transmits voltage, current, or signal information from external wires or cables to the corresponding contact elements of the mating connector. Therefore, the contacts must have excellent structural design, stable and reliable contact retention, and good electrical conductivity. Poor contact performance—such as inadequate contact between the contact and its mating component—can result from improper structural design of the contacts, inappropriate material selection, unstable molds, excessive dimensional tolerances during machining, rough surface finish, improper heat treatment or plating processes, inadequate surface treatment, improper assembly, harsh storage and operating environments, or incorrect handling practices.

2. Poor insulation. The function of an insulator is to maintain proper alignment of the contacts, electrically isolate the contacts from each other, and insulate the contacts from the housing. Therefore, insulators must exhibit excellent electrical performance, mechanical performance, and processability. In particular, with the widespread adoption of high-density, miniaturized terminals, the effective wall thickness of insulators has become increasingly thin. This places even more stringent demands on the insulating structural materials, the precision of injection-molding die design, and the molding technology and processes themselves. Insulation defects such as short circuits, leakage currents, breakdown, and low insulation resistance can arise due to factors including excessive metallic contaminants on or within the insulator surface, surface dust, flux residues, the precipitation of organic substances, adsorption of harmful gases that combine with surface water films to form ion-conducting channels, moisture absorption, mold growth, and aging of insulating materials.

3. Poor fixation. Insulators not only provide electrical insulation but also offer precise neutralization protection to extend contact life; additionally, they serve the functions of installation, positioning, and locking equipment. Poor fixation can lead to poor contact due to transient power failures, resulting in low contact reliability and, in severe cases, complete product failure. Disconnection refers to structural unreliability caused by factors such as materials, design, or technology, leading to abnormal separation between the plug and socket—or even between plugs themselves—thus causing serious disruptions in power transmission and signal control within the control system. Poor fixation can be attributed to unreliable system design, improper material selection, inappropriate choices in molding technology and processes, poor quality in heat treatment, mold manufacturing, assembly, welding, and inadequate assembly procedures.

In addition, appearance defects caused by issues such as peeling of the plating, corrosion, dents, flash on plastic housings, cracks, rough machining of contact components, and deformation— as well as interchangeability problems stemming from excessive tolerances in positioning and locking fits, poor consistency in manufacturing quality, and excessively high total separation forces—are also common and frequently occurring issues. Generally, these faults can be promptly identified and resolved during inspection and use.