But thermal electrical contacts-special conductive bolt rod installation instructions

Overheating of electrical contacts is a major problem that has existed for decades in "various" power systems for power generation, power supply, and electricity consumption. In the national standard "Electrical Device Installation Engineering, Busbar Device Construction and Acceptance Specification" GBJ149-90, the provision of 2.2.3 on page 16 to add a copper flat washer between the nut and the busbar is wrong, and the description of Article 2.2.3 on page 45 is also mentioned Reported to the operating unit that such electrical contacts (terminals) often have overheating accidents. Therefore, it should be taken seriously from the height of safe production, economic operation, and reliable power supply, and fundamentally solve it all at once, instead of following traditional habitual practices, in the process of handling overheating, continue to repeat past mistakes until overheating occurs. If there is a power outage for maintenance, although it is a high-quality service based on repairing the power supply as soon as possible, it is at best a "remedy".

However, thermal electrical contacts-special conductive bolt rods are the book "Electrical Contacts" (to be published) written by senior transformer technician Ren Yi with 40 years of practical experience in production. According to the book, the "four basic principles" of electrical contacts are solved. : 1. The effective current-carrying cross-sectional area is the basis for the electrical contact to overheat; 2. The contact pressure is the key to overheating; 3. The contact corrosion is very important; 4. The electrical contact (including fasteners) material The reduction in contact pressure caused by fatigue should not be ignored; the core is the same advancement and consideration, and the patented technology "overheating electrical contacts and fasteners" ZL01214234.4 is combined to "tailor-made" various types of power systems. of. It is widely used in electrical contacts (terminals) of various high and low voltage electrical appliances such as power transformers, test transformers, current transformers, voltage transformers, and wall bushings. The theory, concept, design, and production of patented technology products are different from "Terminals for Transformers, High-Voltage Electrical Appliances and Bushings" GB5273-85 in that the standard specifications are unreasonable, resulting in overheated electrical contacts. Patented technology products are effective in solving this type of electrical contact overheating, once and for all, and are very convenient for installation, replacement, maintenance and disassembly.

Because of patented technology and patented products-changing traditional habitual mistakes for many years, the following points should be paid attention to when installing, overhauling and using:

1. When installing, the connection between the two patented nuts is the bus bar (transformer lead wire) and tightened with a standard nut to prevent loosening.

Special reminder: There must be no flat washer between the nut and the busbar (the national standard is wrong). Remember! Remember!

2. In handling accidents and emergency repairs, it must not be convenient. Replace the original bolt with a patented nut. The transformer should be lifted and replaced with a patented product. That is, the new transformer should be replaced in a complete set to ensure that the overheating is completely solved at one time. malfunction.

3. The cross-sectional area of ​​the busbars, wires, and cables connected to the patented conductive bolt rods must be sufficient, and the clamps (wiring lugs) used for the wires and cables must be reasonable, qualified, and overheated crimped wires folder. The cross-sectional area of ​​the crimping pipe wall should be more than 1.5 times the cross-sectional area of ​​the wire and cable. The use of bolt-type equipment clamps is strictly prohibited.

4. When connecting the conductive bolt rod and the busbar, the dynamic stability during short circuit should be considered, and the stress here should be minimized to avoid damage to the porcelain bushing or oil leakage of the transformer. At the same time, the aperture of the busbar (clamp, wiring lug) must be equal to the outer diameter of the conductive bolt rod, and the aperture will reduce the effective current-carrying cross-sectional area. Pay special attention during installation.

5. Coat a small amount of compound grease on the contact surface of the nut, the conductive rod wire and the bus bar for corrosion protection and easy disassembly.

Six. When tightening with a special wrench and suitable tools, the torque value is 40-80N.m, especially if the standard nut is tightened to prevent loosening, it is not good for the disassembly to damage the thread if it is too tight.