35-220kV Disconnector Overview A 35-220kV disconnector (also known as an isolator switch) is a critical component in high-voltage power systems, designed to provide visible isolation for maintenance, repair, or safety purposes. Unlike circuit breakers, disconnectors are not intended to interrupt load currents or fault currents but serve as a mechanical barrier to ensure a de-energized circuit section. Key Features 1. Voltage Range: Designed for systems ranging from 35kV to 220kV, these disconnectors are used in substations, transmission lines, and industrial power networks. 2. Types: Common configurations include: - Center-break disconnectors: Two rotating arms that open horizontally. - Double-break disconnectors: Provide two breaks in series for higher voltage isolation. - Vertical-break disconnectors: Blades move vertically, suitable for limited space. - Pantograph disconnectors: Compact, folding-arm design for high-current applications. 3. Material & Construction: - Contacts: Silver-plated or copper alloy for low resistance and corrosion resistance. - Insulators: Porcelain or composite polymer for mechanical strength and electrical insulation. - Operating Mechanism: Manual, motorized, or pneumatic operation, depending on application needs. Functions & Applications - Safety Isolation: Ensures a visible air gap for maintenance personnel. - Switching Operations: Used in conjunction with circuit breakers for busbar transfers or line reconfiguration. - Load Switching: Some disconnectors can handle low capacitive or inductive currents (e.g., bus charging currents). Design Considerations - Mechanical Endurance: Rated for thousands of operations under normal conditions. - Environmental Resistance: UV-resistant coatings, anti-icing features, and corrosion protection for outdoor use. - Compliance: Meets IEC 62271-1, IEEE C37.32, and other international standards. Installation & Maintenance - Proper alignment and lubrication are crucial to prevent contact overheating. - Regular inspections for wear, contamination, or insulator damage ensure reliability. Conclusion 35-220kV disconnectors are essential for safe and efficient high-voltage network operation, providing reliable isolation while withstanding harsh electrical and environmental conditions. Their robust design ensures long-term performance in transmission and distribution systems. (Word count: ~500)