Overview
The Klockner Moeller NZM6b-63 is a molded case circuit breaker engineered for demanding industrial and commercial power distribution systems. The Klockner Moeller NZM6B-63 series molded case circuit breakers are designed for demanding industrial and commercial power distribution systems. Built on a 63A frame with the ZM6-50-320 thermal-magnetic trip unit and CNA (North American) regional configuration, this breaker provides flexible, precise overcurrent protection.
Key Features
- Built on a 63A frame, these breakers support a wide range of trip unit configurations—including fixed and adjustable thermal-magnetic (ZM6, ZM6A) and electronic (ZM6-OBI) options—allowing precise protection from 1.2A up to 2000A.
- Each unit comes with field-wiring terminals for both line and load sides and is designed to operate at voltages up to 690V AC.
- Thermal-magnetic trip unit with adjustable settings for flexible coordination in complex distribution networks
- Select models feature adjustable instantaneous and long-time trip functions to enhance coordination and selectivity in complex systems.
- These breakers conform to global safety standards and are UL 489 and CSA C22.2 No. 5.1 certified.
Technical Specifications
- Trip Unit Type: ZM6-50-320 (thermal-magnetic)
- Pole Configuration: 3-pole
- Frame Rating: 63A
- Maximum Voltage: Up to 690V AC
- Regional Configuration: CNA (North American)
- Certifications: UL 489, CSA C22.2 No. 5.1
- Trip Unit Flexibility: Adjustable thermal and magnetic settings
- Operating Terminals: Field-wiring capability on line and load sides
Typical Applications
With robust protection and wide configurability, the NZM6B-63 series supports applications across motor protection, feeder circuits, and main switchboards. The ZM6-50-320 trip unit configuration is ideal for:
- Motor circuit protection in industrial machinery
- Feeder circuits in distribution panels
- Main switchboard protection
- Equipment requiring adjustable thermal-magnetic coordination
- Systems operating up to 690V in North American installations
Compatibility & Replacements
Compatible With
- Industrial power distribution systems rated up to 690V AC
- Standard DIN rail mounting panels
- Three-phase power networks
- Motor control centers (MCCs) and switchboards
- Field-wired line and load terminals
Replaces / Drop-In Replacement For
Verify compatibility with your system integrator before ordering. Other NZM6b-63 variants with different trip unit ratings (ZM6A series, different amperage settings) may offer similar base compatibility but require specification matching.
Works With
- Klockner Moeller NZM6b frame-based equipment
- Standard industrial electrical enclosures and distribution panels
- Thermal-magnetic coordination schemes in multi-level protection systems
- North American electrical codes and standards (UL 489, CSA C22.2)








