HOW TO SOLVE THE COMMON PROBLEMS OF PLUG-IN TERMINALS?

The plastic insulation and conductive part of the terminal is directly related to the quality of the terminal , which determines the insulation and conductivity of the terminal . The failure of any terminal will lead to the failure of the whole system engineering. The past experience and lessons are very profound. Various problems may occur during the usage of terminals. Let's learn more about the problems and reasons below.

1. Wiring Terminal Blackened

If the terminal  is black, it may not be burnt black, or it may be oxidized black. Wipe it with fingers. If it can be wiped off like soot, it is the black substance formed by oxidation. It can only be worn off with sandpaper or file. Please pay much attention here not to use fingers to wipe when it is electrified.

2. Overheating and High Temperature

There are two possibilities for overheating. The contact resistance is too large due to the loose terminal, so the terminal  is overheated. Or the terminal is not loose, but the circuit is overheated due to some unknown reason, such as the power supply voltage is too high, or the load is short circuited.

(1) Voltage too High

It can be checked from the source, from the first level to the next level, from the secondary voltage of the transformer to the voltage in the distribution box, and then to the voltage of each electrical equipment.

(2) Earth Fault

It can be checked from the transformer and then earthed to the distribution box. The grounding shall be earthed, and the normal phase line shall be removed from the grounding fault. The insulation meter or megger can be applied to measure when the power is cut off. The power supply and distribution lines such as cables, wires, breakers, switches, etc. shall be measured in sections as far as possible. If it is difficult to segmentation, the fuse of weak current equipment and sensing equipment can be pulled out. The key of grounding is to have low resistance and large contact area.

3. Short Circuit Fault

The failure of wires and terminals may also be caused by a short circuit between the wire harness and the body (ground wire) or within the switch concerned. Before inspection, first check whether the terminals on the body are firmly fixed, and then test according to the following steps.

(1) Check Whether the Wire is On or Off

First remove the terminals on both sides of the control computer ECU and the sensor, and then measure the resistance between the corresponding terminals. If the resistance is not greater than 1 ohm, the wire is normal for the next check.

(2) Short Circuit Resistance Check

First, remove the wiring terminals on both sides of the control computer ECU and the sensor, and then measure the resistance between each terminal block of the connectors on both sides and the body. During measurement, one end of the meter bar shall be grounded to the body, and the other end shall be measured on the wire connectors on both sides respectively. If the resistance value is greater than 1 ohm, it means that there is no short circuit fault between the wire and the body.

(3) Terminal Appearance and Contact Pressure Inspection

First, remove each terminal  one by one, check whether there is rust contact and dirt on the connector terminal, and clean the rust and dirt. Then check whether the terminal strip is loose or damaged and whether the terminal  is fixed firmly. The terminal should not be loose when pulled gently. On the contrary, if the plug-in terminal in one socket is easier to pull out than other sockets, the socket may cause poor contact in application.

The terminal is the foundation. Through timely analysis and screening, various failure modes and failure mechanisms are found. A large number of lessons are summed up and various hidden dangers are eliminated. Thus, prevention is carried out in advance, so as to prevent accidents in advance, either.

Cixi Kefa Electronic Co., Ltd. specializes in the production of all kinds of terminals, terminal blocks, PCB terminals, electronic connectors and precision molds.