Flat cables have a wide range of applications, involving power, construction, communication, manufacturing, and other industries, and are closely related to all sectors of the domestic economy. The terminal heads and their used insulating materials should be standardized products, with all connection points sealed tightly, accessories complete, and porcelain sleeves free of cracks or damage. They must meet the voltage grade and design requirements, and should have test data and a certificate of compliance. Next, let's discuss the issues that should be noted in terms of technology when installing joints.
Prior to connecting the conductors, shape the insulation ends on both sides into a conical form (i.e., the reaction force cone). Leave the inner屏蔽 slightly longer than usual by about 10mm. After pressing or welding, remove burrs and excess edges from the connection surface. Clean the metal shavings from the connection surface with a white rag dampened with gasoline. At this point, use a semi-conductive rubber self-adhesive tape to fill the depression on the connection surface. Then, wrap the connection with a semi-overlapping method to fill the gap between the connection surface and the semi-conductive inner shielding layer of the wire core. Ensure careful wrapping, pressing with hands to eliminate gaps, and creating a uniform electric field. Next, overlap wrap two layers of semi-conductive tape on the connection surface and extend it up to 10mm on the insulation of the reaction force cone. This wrapping process ensures that even if the main insulation retracts, it is generally below 10mm, and the shielding effect remains. When increasing the insulation winding, wrap six layers using self-adhesive insulation tape, stretching it to half its width and overlapping as you wrap. This creates a certain amount of tension to pull the tape inward, and pressing it with hands as you wrap helps to expel air gaps.
Flat cables will definitely heat up when passing a certain load current. As the load current increases, the surface temperature becomes higher. If not addressed promptly, the consequences are predictable. After heat generation, if the cause is not identified and the fault is not eliminated in time, an insulation thermal breakdown will occur upon continuous power-on operation. This can lead to inter-phase short-circuit tripping and, in severe cases, may cause a fire. The following are reasons for heating during operation:
Conductor resistance did not meet specifications, resulting in overheating during operation.
2. Inadequate selection led to the use of cables with excessively small conductor cross-sections, resulting in overload during operation. Over time, uneven heating and cooling caused by prolonged use led to overheating.
3. Overly dense arrangement during installation can lead to poor ventilation and heat dissipation, or being too close to other heat sources, affecting normal heat dissipation and potentially causing overheating during operation.
4. Poor joint manufacturing techniques result in loose crimps, leading to excessive contact resistance at the joint and causing overheating phenomena.
5. The alternating insulation performance is poor, resulting in a smaller insulation resistance and the occurrence of heat generation during operation.
6. Local sheath damage allows water intrusion, which gradually deteriorates the insulation performance, leading to a gradual decrease in insulation resistance and causing overheating during operation.
