DIN Rail Changeover Switch 125A

The CDADA SF Series DIN Rail Changeover Switch 125A is a robust, manually operated switching solution designed by Shanghai DADA Electric CO.,LTD for reliable dual power source or load conversion in commercial, industrial, and infrastructure applications. Compliant with IEC 60947-3 and EN 60947-3, this switch supports AC 50/60Hz systems up to 400V and handles continuous currents up to 125A under AC-22A utilization category (mixed resistive and inductive loads).

Featuring a clear 3-position manual handle (I – OFF – II), it enables safe switching between main grid and backup generator, dual transformers, or redundant circuits, while the center OFF position ensures complete isolation—critical for maintenance and safety. Designed for standard TH35 DIN rail mounting, it integrates seamlessly into modern distribution boards alongside MCBs, contactors, and surge protectors.

With high-conductivity contacts, spring-assisted quick-make/break mechanism, and precision-lubricated internal components, the 125A model delivers 8,500 mechanical operations and 1,500 electrical cycles under rated conditions. Note: it lacks an arc extinguishing chamber, so must be used with upstream fuses or circuit breakers for short-circuit protection.

Key Specifications (125A Model)

Why Choose CDADA DIN Rail Changeover Switch 125A?

★ High-Current Reliability

Engineered for continuous 125A duty—ideal for large pumps, HVAC units, or data center backup systems.

★ True Isolation with OFF Position

Center “O” position disconnects both sources, eliminating risk of backfeed or accidental energization.

★ DIN-Rail Ready for Modern Panels

Saves space and simplifies installation in compact or modular distribution boards.

★  Industrial-Grade Construction

Spring-loaded contacts, lubricated spindle, and 50mm² terminal capacity ensure long-term stability.

★ Global Standards Compliance

Certified to IEC 60947-3—accepted worldwide for commercial and light-industrial use.

★ Safe Operation Guidance

Includes extended handle recommendation for 125A models—ensures controlled, full-travel switching.

Typical Applications

Emergency Power Transfer: Main grid ↔ Generator (hospitals, telecom towers)

Redundant Power Systems: Dual UPS or transformer switching

Industrial Machinery: Source selection for large motors or heating systems

Building Management: Backup lighting or elevator power routing

Renewable Integration: Grid vs. solar hybrid system isolation

About CDADA

★ We have professional R & D team, have standard development process. Can provide excellent customized service.

★ We have fully functional laboratory, our laboratory can witnessed laboratory , we can done thermal load, magnetic, and tripping limit, mechanism life, EMC in our laboratory.  

★ we offer structured partnership programs for distributors, agents, and OEM partners in key markets, providing sales support, marketing materials, and competitive terms.

★ Company profile

Frequently Asked Questions

Q1: Can I switch the DIN Rail Changeover Switch 125A under load?

A1: No. This switch has no arc extinguishing capability. It must be operated only when de-energized or used strictly as an isolator (no-load switching). For live-load transfer, use an automatic transfer switch (ATS) or fused motorized switch.

Q2: Why does the 125A model require two hands or an extended handle?

A2: The spring mechanism in high-current models generates significant inertial force. A single-handed operation may result in incomplete contact engagement, causing arcing or overheating. CDADA recommends both hands or the factory-provided extended handle for safe, full-travel operation.

Q3: What cable size is required for 125A?

A3: Use 50mm² copper cable (as per provided specs). Ensure terminals are tightened to 3.5 N·m to prevent overheating.

Q4: Do I need fuses with this switch?

A4: Yes. Since it cannot interrupt short-circuit currents, always install upstream fuses or MCBs rated for your system’s prospective fault level. The switch only provides manual isolation/conversion.

Q5: Why choose CDADA over competitors for 125A changeover?

A5: CDADA offers:

● True 3-position mechanical interlock (no floating states)

● IEC 60947-3 certification with global acceptance

● Optimized thermal design for DIN-rail enclosures

● Clear visual indication of switch position

● Competitive pricing with technical support in English