Withdrawable AC Armored Metal-Enclosed MV Switchgear

Withdrawable AC Armored Metal-Enclosed MV Switchgear

Engineered for demanding medium voltage distribution networks, our withdrawable AC armored metal-enclosed switchgear delivers uncompromising safety and operational continuity. The design draws on decades of field experience, integrating fully compartmentalized, metal-enclosed construction with arc-fault containment tested to IEC 62271-200. This equipment forms the backbone of the AC Metal-Clad Armoured Switchgear family, ensuring personnel protection by separating busbar, circuit breaker, cable, and low-voltage control sections into individually earthed metallic enclosures. Whether deployed in utility substations, heavy industry, or critical infrastructure, the withdrawable breaker truck guides smoothly on precision rails, allowing rapid inspection, maintenance, or replacement without de-energizing adjacent feeders. Interlocked shutters automatically cover fixed primary contacts as the breaker is racked out, eliminating exposure to live parts. Continuous thermal ratings typically span 630 A to 4000 A, with short-time withstand currents up to 50 kA/3 s, making the switchgear suitable for transformers, capacitor banks, and motor feeder applications where reliable arc protection and minimized downtime are priorities.

Withdrawable AC Armored Metal-Enclosed MV Switchgear is factory assembled and type tested as a complete unit, giving specifiers confidence that every compartment meets rated insulation levels, internal arc classification, and mechanical endurance requirements before leaving the factory. All functional units arrive pre-wired and tested, reducing site assembly time and the risk of installation errors. The withdrawable feature means that a single operator can isolate a circuit in seconds, and the earthing switch, with full rated making capacity, can be closed from the front with the door shut, maintaining metallic enclosure integrity throughout earthing operations. Voltage transformers, current transformers, and protective relays mount in dedicated compartments, and optional capacitive voltage indicators verify dead status before earthing. The low-voltage marshalling box accommodates advanced microprocessor-based relays, communication modules, and interlock logic, enabling seamless integration into SCADA and smart grid systems. Gas-insulated busbar variants are available for height-constrained substations, while air-insulated busbar versions provide economic efficiency for standard indoor applications, all maintaining the core armored, withdrawable architecture that operators trust for long service life and easy retrofitting.

Key Technical Specifications

• Rated voltage: up to 40.5 kV (IEC) / 38 kV (IEEE)
• Rated busbar current: 630 A, 1250 A, 2000 A, 2500 A, 3150 A, 4000 A
• Rated short-time withstand current: 25 kA / 31.5 kA / 40 kA / 50 kA (3 seconds)
• Rated peak withstand current: up to 125 kA
• Internal arc classification: IAC AFLR up to 50 kA/1 s (IEC 62271-200)
• Loss of service continuity category: LSC2B
• Partition class: PM (metallic partitions between compartments)
• Busbar insulation: air or SF6 gas, joints sealed with prefabricated boots
• Degree of protection: IP4X for enclosure, IP2X between compartments when door is open
• Earthing switch: manual or motorized, rated making capacity equal to rated short-circuit current
• Breaker technology: vacuum circuit breaker with serial toggle mechanism
• Control voltage: 110 V DC, 220 V DC, 230 V AC (customizable)
• Standards: IEC 62271-200, IEC 62271-100, GB 3906, IEEE C37.20.2 / C37.04

Every cubicle undergoes routine tests including power-frequency voltage withstand, circuit resistance measurement, and mechanical operation checks before delivery. Optional seismic qualification up to 0.5g ground acceleration and tropicalized painting systems ensure fitness for diverse environments. Draw-out interlocks comply with IEC fail-safe logic, preventing racking when the breaker is in closed position and guaranteeing closure only in the fully connected position. The switchgear can be customized with embedded temperature monitoring, partial discharge sensors, and IEC 61850 process bus integration, making it an adaptable platform for digital substation architectures.