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Common Faults and Solutions of Electrical Terminal Blocks
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Common Faults and Solutions of Electrical Terminal Blocks

Views: 41     Author: Site Editor     Publish Time: 2020-06-30      Origin: Site

From the point of view of use, the function that the electrical terminal blocks should achieve is that the contact part must be connected and the contact is reliable. Where the insulation part should not be connected, the insulation must be reliable. There are three common fatal failure modes of electrical terminal blocks: Poor contact,Poor insulation and Poor fixation.

Damaged parts and causes of electrical terminal blocks

The following is the analysis of common damaged parts and causes:

  Damaged parts

  Cause analysis


  Unqualified size, material (insufficient elasticity,   insufficient elasticity continuity), mixing.


  Slippery wire, broken, rusted, salt spray   test failed, the material is too soft, the screw head is fluffy, the material   is not in accordance with the customer's requirements, the torque is not qualified,   the size is not standard, and the mixture.


  Mismatching, broken crimping, crimping   frame (sliding wire, too tight or not screwed in), poor electroplating,   deformation, connection hole (sliding wire, too tight or not screwed in),   salt spray test failure, poor welding.


  Non flame retardant, broken foot, guide   rail stuck, lack of material, water bloom, deformation, burr, mixture,   product mismatch, color mismatch, color inconsistency.


  Poor contact, burnout and short circuit

  The material is unqualified, the screw is   slippery, the customer does not tighten the screw, the screw is loose during   transportation and use, the spring drawing force is not enough, the current   overload is overload, the wire is connected wrongly and causes short circuit.

  Rail terminal slide wire

  The screw is too tight, there is no screw   or thread, the screw is not retreated, not flame retardant, broken foot,   rusty, salt spray test is not qualified, the elasticity is not enough, the   elasticity is not enough, the assembly is not in accordance with the drawing,   the installation is missing, the model is wrong, and the appearance is rough.

  PCB terminal slide wire

  Screw is too tight, no screw or thread, non-flame   retardant, broken foot, broken clamping point, screw is not retreated,   rusted, salt spray test is not qualified, spring compression force is not   enough, spring compression force is not enough, color difference, mismatch,   poor weldability, deformation, mixing, button handle is not rebounded, needle   distance is too large, too small.

Failure prevention test of electrical terminal blocks

In order to ensure the quality and reliability of the electrical terminal connectors and prevent the occurrence of the above faults, it is recommended to study and formulate the corresponding screening technical requirements according to the technical conditions of the product, and carry out the following targeted reliability test for failure prevention.

1. Prevent poor contact           

 1) Continuity test

 2) Instantaneous break detection            

Some electrical connector blocks are used in a dynamic vibration environment. It is proved by experiments that the static contact resistance can not guarantee contact reliability in a dynamic environment. Because the electrical terminal connectors with qualified contact resistance still have an instantaneous power failure in vibration, impact, and other simulation environment tests, it is better to conduct dynamic vibration tests on some industrial terminal blocks with high-reliability requirements to check their contact reliability.

 3) Single-hole separation force detection            

Single-hole separation force refers to the separation force which changes from a static state to moving state of the contact piece, which is used to indicate that the pin and the socket are in contact. The experimental results show that the single hole separation force is too small, which may cause signal instantaneous break under vibration and impact load. It is more effective to check the contact reliability by measuring the separation force of a single hole than to measure the contact resistance.

2. Prevent poor insulation            

Inspection of insulating materials            

The quality of raw materials has a great influence on the insulation performance of electrical connector blocks. Therefore, the selection of raw material manufacturers is particularly important. Do not blindly reduce the cost so that you lose the material quality. You should select large-scale materials with a good reputation. You should carefully check the batch number, material certification, and other important information of each batch of materials. Do a good job in the traceability of materials.

electrical connector blocks

3. Prevent poor fixation            

 1) Interchangeability check            

Interchangeability check is a kind of dynamic check. It requires that the same series of matching plugs and sockets can be inserted and connected with each other. It is found out whether there is any failure to insert, locate and lock due to the size of insulator, contact and other parts are out of tolerance, lack of parts or assembly is not in place, or even disassembly under the action of rotation force.            

 2) Torque resistance inspection            

It is an effective method to check the reliability of the electrical terminal block structure.

 3) Through measurement of crimping wire            

During electrical installation, it is often found that the crimping wires of individual cores are not delivered in place, or cannot be locked and contacted reliably after being delivered to the position. The analysis reason is that there is burr or dirt stuck in the screw teeth of the individual installation hole.

As famous China terminal block manufacturers, Sun provides professional electrical terminal block information and high-quality electrical terminal connectors. If you have any needs, please contact us.

Sun Electric Co., Ltd
Founded in 2011, Sun Electric Co., Ltd specializes in the production of terminal blocks and industrial electrical connection products.

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