Chint NXB63-2P/C63 Miniature Circuit Breaker (MCB)

Model Interpretation: NXB63 (frame size 63A) 2P (two poles, simultaneous breaking of live and neutral wires) C63 (C-type tripping, rated current 63A)

コア技術パラメータ (Compliant with IEC 60898-1/GB/T 10963.1)

Functions & Applications

Core Functions: Overload protection, short-circuit protection, isolation; no earth leakage protection (select NXBLE-63 2P C63 if required)

Typical Scenarios:

Main switch for residential/commercial premises (220V/380V incoming line)

Main switch for high-power equipment (e.g. air conditioners, 電気温水器, small motors)

Branch protection for commercial/light industrial distribution boxes

Selection Tip: C-type is suitable for most lighting, socket, and general motor loads; D-type is for high inrush current equipment such as transformers and water pumps

インストール & Maintenance Key Points

1. Connect incoming line to the upper terminal and outgoing line to the lower terminal; for 2P breakers, wire according to phase sequence to ensure simultaneous make-and-break.
2. Tighten terminals to 2.0 N·m to avoid overheating or loosening.
3. Regular inspection (quarterly): Check handle position (red for closed, green for open), wiring for overheating, and absence of abnormal noise.
4. After tripping, troubleshoot the cause of overload/short circuit first before closing the breaker; never force closing with fault existing.

Replacement & Accessories

Series Replacement: NXB63-2P D63 (D-type), NXB63H-2P C63 (high breaking capacity 7.5kA)

Earth Leakage Protection Accessory: NXBLE-63 2P C63 (residual current 30mA)

Brand Replacement Reference: Schneider iC60N 2P C63 (breaking capacity 6kA, compatible in size and mounting)

Detailed Parameter Comparison and Replacement Guide: Chint NXB63-2P/C63 vs Schneider iC60N 2P C63

1. Core Parameter Comparison Table

2. Key Replacement Precautions
3. Installation Compatibility Confirmation

✅ Rail Matching: Both are mounted on 35mm DIN rails with 18mm width, allowing direct interchange of installation positions.

✅ Distribution Box Space: Identical dimensions (18×91×65mm) eliminate the need for box hole modification.

⚠️ Spacing with Adjacent Components: Ensure a minimum gap of ≥3mm from left and right components. Schneider iC60N terminals are slightly wider, so avoid wiring interference.

2. Electrical Performance Matching Key Points

✅ Breaking Capacity: Schneider iC60N is marked with dual breaking capacities of 6kA/10kA, while Chint NXB63 is standard 6kA with 10kA for specific versions. During replacement, confirm the system short-circuit current level to ensure it does not exceed the breaker’s breaking capacity.

✅ Tripping Characteristics: Identical C-type curves, suitable for mixed loads such as lighting, ソケット, and general motors, with no need to adjust load types.

⚠️ Rated Current: Must strictly maintain 63A; do not use lower-rated breakers to avoid overload protection failure.

3. Wiring Operation Specifications
4. Power-off Safety: Cut off the upstream power supply before replacement and use a voltage tester to confirm no electricity. Implement Lockout-Tagout (LOTO) procedures for industrial scenarios.
5. Cable Size Adaptation: Schneider iC60N terminals can accommodate larger cable sizes (up to 35mm² solid cable), but keep the original cable size during replacement to prevent loose connections due to oversized cables.
6. Torque Control: Schneider terminals require 2.5 N·m, higher than Chint’s 2.0 N·m. Use a torque screwdriver for tightening to prevent terminal overheating or loosening.
7. Phase Sequence Maintenance: For 2P breakers, wire according to L1/N or L1/L2 phase sequence to ensure simultaneous make-and-break. Mark wire ends clearly during replacement to avoid reverse connection.
8. Function & Maintenance Adaptation

⚠️ Fault Indication: Schneider iC60N is equipped with VisiTrip fault indication (red display after tripping) and VisiSafe isolation indication (green bar for isolation status). Train operators to recognize new status marks after replacement.

✅ Operation Feel: Both adopt standard rocker handles with consistent operation logic (up for close, down for open), requiring no re-learning.

⚠️ Maintenance Cycle: Schneider recommends semi-annual inspection while Chint recommends quarterly inspection. Unify the inspection standard according to the stricter quarterly cycle.

5. コンプライアンス & Warranty Tips

✅ Certification Validity: Both have CCC certification for domestic projects. For export projects, confirm the target market’s certification requirements (Schneider additionally has UL/CSA certifications).

⚠️ Warranty Difference: Chint offers 18-month warranty while Schneider offers 24-month warranty. The warranty period shall follow the new product after replacement.

⚠️ Anti-counterfeiting Verification: Counterfeit products are common in the market. Purchase through official channels. Schneider products can be verified via anti-counterfeiting labels and Chint products via 2D barcodes.

3. Replacement Operation Steps
4. Preparation Work:

Confirm the new breaker model is Schneider iC60N 2P C63 (A9F77263).

Prepare tools: Phillips screwdriver, torque screwdriver (2.5 N·m), voltage tester, insulated gloves.

Record the original wiring positions and phase sequence marks.

2. Power-off & Verification:

Turn off the upstream main switch and wait 5 minutes for discharge.

Use a voltage tester to confirm no voltage at both incoming and outgoing terminals of Chint NXB63-2P/C63.

3. Removal of Old Breaker:

Loosen terminal screws and remove incoming/outgoing wires (mark them clearly).

Press the DIN rail release tab and remove NXB63 from the rail.

4. Installation of New Breaker:

Snap Schneider iC60N onto the DIN rail and ensure the locking tab is engaged.

Wire according to original marks, connecting incoming wires first then outgoing wires. Strip cable ends to 10~12mm length.

Tighten terminal screws to 2.5 N·m with a torque screwdriver.

5. Testing & Verification:

Close the breaker for test: Check handle position and status indication for normal operation.

Optional overload/short-circuit simulation test: Confirm protection functions are effective.

Inspect terminal connections for overheating or loosening and check for abnormal noise.

4. Applicable & Inapplicable Replacement Scenarios

✅ Recommended Replacement Scenarios

Upgrade of main switches for residential/commercial premises (220V/380V incoming line)

Replacement of main switches for high-power equipment (air conditioners, 電気温水器, small motors)

Update of branch protection for commercial/light industrial distribution boxes

Direct replacement of faulty old NXB63 breakers

❌ Not Recommended Replacement Scenarios

System short-circuit current > 6の, with Chint NXB63 being 10kA version while Schneider iC60N is only 6kA version

Wiring cable size > 16mm² (Chint NXB63 maximum support 16mm²), requiring terminal or cable size replacement

Low-temperature environment (<-25℃): Schneider iC60N minimum operating temperature is -25℃, lower than Chint’s -30℃

5. まとめ & Selection Recommendations

Chint NXB63-2P/C63 and Schneider iC60N 2P C63 are same-grade, same-specification miniature circuit breakers with completely consistent core protection functions, enabling direct interchangeable use.

Selection Recommendations:

Pursuing cost-effectiveness: Choose Chint NXB63-2P/C63, priced at approximately 60~70% of Schneider.

Pursuing international certifications and additional functions: Choose Schneider iC60N 2P C63, which provides more comprehensive fault indication and bidirectional wiring functions.

Industrial/export projects: Prioritize Schneider iC60N with UL/CSA certifications and higher global recognition.