Siemens 3AP1 DT126 and Chinese Equivalent Products

Complete Analysis of Siemens 3AP1 DT126 and Chinese Equivalent Products

1. Product Overview of Siemens 3AP1 DT126

The Siemens 3AP1 DT126 is an outdoor SF6 gas-insulated dead-tank circuit breaker rated at 126 kV (123 kV), belonging to the Siemens 3AP1 DT series. It is mainly used for control and protection in power systems, and can also serve as a tie circuit breaker.

Product Features

Dead-tank structure: Arc-extinguishing chamber and conductive parts sealed in a metal tank, stable against external environment, high operational reliability.

Self-energy arc quenching: Uses arc’s own energy to extinguish the arc, reducing operating power requirements.

Design modular: Easy installation, maintenance and component replacement.

Strong environmental adaptability: Operates normally from -40 °C to +40 °C; some versions down to -60 °C.

2. Recommended Chinese Equivalent Products (126 kV Dead‑Tank SF6 Circuit Breakers)

Leading Chinese high-voltage switch manufacturers (Pinggao Electric, XD Xi’an Switchgear, NEPI) offer mature 126 kV dead-tank circuit breakers with technical parameters highly matching the Siemens 3AP1 DT126, suitable for direct replacement.

2.1 XD Xi’an Switchgear LW24‑126/T3150‑40 Dead‑Tank Circuit Breaker

Flagship product of Xi’an XD High Voltage Switchgear Co., Ltd. Type-tested and certified at national level in 2002, with extensive service experience in extremely cold regions.

Advantages for replacement: Excellent low-temperature performance, mature application in extremely cold regions such as Russia; strong technical heritage of XD Group, complete after-sales service network.

2.2 Pinggao Electric LW36‑126/T3150‑40 Dead‑Tank Circuit Breaker

Independently developed by Pinggao Group, widely used in State Grid and China Southern Power Grid projects.

Advantages for replacement: Wide range of breaking capacities (40 kA/50 kA) adaptable to different grid short-circuit levels; rich UHV experience, reliable quality.

2.3 NEPI (Shenyang HV Switch) LW36‑126/T3150‑40 Dead‑Tank Circuit Breaker

Inherits technology from the former Shenyang High Voltage Switchgear Factory; among the first domestic products to pass type tests for 126 kV dead-tank circuit breakers.

Advantages for replacement: Strong price competitiveness, fast after-sales response; large installed base in Northeast and North China grids.

2.4 Sieyuan Electric ZCW‑126 Dead‑Tank Circuit Breaker

Independently developed by Sieyuan Electric, featuring external air insulation + internal SF6 insulation, compact design.

Advantages for replacement: Advanced eco-design, low SF6 usage; high intelligence, supports condition monitoring.

3. Key Considerations for Replacement Selection

3.1 Parameter Matching Principles

Core parameters must be identical: tensiunea nominală (126 kV), curent nominal (3150 O), rated short-circuit breaking current (40 cel).

Operating mechanism: Prefer spring mechanism for consistent operation with original equipment.

Mounting dimensions: Verify foundation and interface compatibility to avoid civil modification.

Circuit de control: Ensure secondary control voltage and interface match the existing system.

3.2 Technical Performance Comparison

3.3 Implementation Recommendations

1. Technical evaluation: Conduct full system assessment by professional power engineering company to confirm feasibility.
2. Prototype testing: For critical projects, pilot with 1–2 units for on-site trial operation to verify stability.
3. Instalare & punerea în funcţiune: Follow manufacturer instructions strictly; focus on sealing and mechanical characteristics.
4. Personnel training: Train operation and maintenance staff on the replacement product.
5. Spare parts inventory: Maintain reasonable stock for long-term reliable operation.
6. Summary Table of Recommended Replacement Products