Description
The Siemens® NXD63B120 is a Sentron Series molded case circuit breaker (MCCB) designed for high-capacity protection in industrial and commercial power distribution systems. Rated for 1200 amps, 600 volts, and 3 poles, it features a thermal-magnetic, non-interchangeable trip unit that delivers dependable overload and short-circuit protection. Built on the ND frame, this breaker combines robust construction with standard interrupting capacity for reliable performance under heavy electrical loads.
Technical Specifications
| Condition |
New/Never Used Surplus |
| Brand |
Siemens / ITE |
| Category |
Circuit Protection Devices |
| Part Number |
NXD63B120 |
| Subcategory |
Molded Case Circuit Breaker |
| Series |
Sentron Series |
| Frame Type |
ND Frame |
| Number of Poles |
3 |
| Phase |
3-Phase |
| Rated Current |
1200 A |
| Rated Voltage |
600 VAC |
| Interrupting Capacity |
25 kA @ 600V, 50 kA @ 480V |
| Trip Unit Type |
Thermal-Magnetic (non-interchangeable) |
| Protection Type |
Long-Time (overload) and Instantaneous (short-circuit) |
| Calibration Temperature |
40°C (standard) |
| Mounting Type |
Bolt-On |
| Terminal Type |
No lugs installed (field-configurable) |
| Approvals / Standards |
UL 489, IEC 60947-2 |
| Design Feature |
Standard breaking capacity |
| Enclosure Rating |
Suitable for enclosed panelboard installation |
| Dimensions (W × H × D) |
9 × 16 × 6 in |
| Material |
Molded case with steel mounting hardware |
| Operating Frequency |
50/60 Hz |
| Manufacturer |
Siemens Breakers |
| Weight |
47 lbs (approx.) |
Information About NXD63B120
The NXD63B120 belongs to the Siemens Sentron NXD family of molded case circuit breakers, engineered for precision and safety in low-voltage electrical systems. Designed for 3-phase, 600V AC operation, it supports an interrupting capacity of 50 kA at 480V and 25 kA at 600V, providing strong fault-clearing capability for critical installations. This model features a bolt-on mounting design for secure panel integration and includes a non-interchangeable thermal-magnetic trip unit, which combines long-time overload and instantaneous short-circuit protection. Operating at a standard 40°C calibration, the NXD63B120 complies with UL 489 and IEC 60947-2 standards, making it suitable for power distribution panels, switchboards, and control assemblies requiring durable, high-current circuit protection.
Key Features:
- High Current Capacity: Rated 1200A, ideal for large-scale electrical distribution systems.
- Thermal-Magnetic Trip Unit: Provides both overload (thermal) and short-circuit (magnetic) protection.
- Standard Interrupting Ratings: 50 kA @ 480V and 25 kA @ 600V for dependable fault clearing.
- Bolt-On Mounting: Ensures a secure and stable installation in panelboards or switchgear.
- Non-Interchangeable Trip Unit: Factory-calibrated for optimal performance and reliability.
- UL 489 and IEC 60947-2 Certified: Meets international standards for molded case circuit breakers.
- Compact ND Frame: Space-efficient 9 × 16 × 6 in. design for simplified integration.
- Rugged Construction: Engineered for durability in harsh industrial operating conditions.
The NXD63B120 delivers the high current protection and reliability demanded in industrial power distribution and motor control systems.
