Tram Copper Sliding Wire DARUI
Darui Electric recommends
In the operation of overhead contact lines, to ensure that the contact wire does not break under a certain tension, it is required to conduct a wear measurement of the contact wire at least once a year. When the wear of the overhead contact line contact wire reaches a certain level, it should be reinforced or replaced. If the average wear of the contact wire in the entire anchor section exceeds 25% of the cross-sectional area of that type of contact wire, it should be completely replaced. If the average wear does not reach 25%, but local wear exceeds 30%, local reinforcement can be carried out. When local wear reaches 40%, it should be replaced.
The focus of wear measurement should be on positioning points, electrical connections, wire joints, center anchorages, electrical phase separations, and electrical sectioning joints. For wear measurement, use a vernier caliper to measure the residual height of the contact wire, and then consult the wear conversion table for that type of contact wire to determine the wear area (the cross-sectional area worn away) at that location.
Contact wire zigzag value and pull-out value
The positioning device fixes the contact wire in the correct position, which is called positioning. The point where the positioning device's positioning clamp fixes the contact wire is called the positioning point. The horizontal distance from the positioning point to the centerline of the pantograph's running track is called the zigzag value in straight sections and the pull-out value in curved sections. The function of the zigzag value and pull-out value is to ensure uniform wear of the pantograph slide plate and to prevent accidents such as pantograph detachment and scraping.
In straight sections, the pantograph center coincides with the track center, and the zigzag value of the contact wire is arranged symmetrically about the track center, with a standard of ±300mm. After speed increase, it is between 200 and 250mm; the pull-out value is between 350 and 450mm.
In curved sections, the pull-out value is related to the radius of the curve.
Insulators used in overhead contact lines
Insulators are used to suspend and maintain electrical insulation from grounded parts.
The insulators used on overhead contact lines are generally porcelain, made by adding quartz and feldspar to porcelain clay and firing them, with a smooth glaze on the surface.
Tram Copper Sliding WireInsulators used on overhead contact lines are divided into two types by structure: suspension-type and post-type insulators; by surface length (i.e., leakage distance), they can be divided into ordinary and anti-fouling types. In recent years, toughened glass suspension insulators have been widely promoted. These insulators have high mechanical strength (2 to 3 times that of porcelain insulators), good electrical performance (average breakdown strength under impulse waves is 3.5 times that of porcelain insulators), long service life, resistance to aging, easy maintenance, and good self-cleaning properties. Their characteristic is "zero-value self-breakage," meaning that when the insulator loses its insulating performance or is mechanically overloaded, the shed will automatically crack and fall off, making it easy to detect and replace in time. In recent years, China has developed and used e?1 type epoxy resin insulators, fluoroplastic and silicone rubber rod-post insulators, and semi-x?5 type and semi-TX-25 type semiconductor glaze insulators. Semiconductor glaze insulators greatly extend the cleaning cycle of insulators, improve power supply reliability, and have shown good trial results, but they have disadvantages such as relatively large leakage current. A more ideal new type of insulator is the composite polymer insulator. This insulator is made by combining two polymer materials: one material enhances mechanical strength, and the other enhances insulating performance, so that the composite polymer insulator can meet the requirements of high mechanical strength, good insulation performance, impact resistance, arc resistance, and light weight. This is also the future development direction of insulators
Note: The above information and technical parameters are compiled and released by Yangzhou Darui Electric Co., Ltd.
