CND63B900 - 900Amp Circuit Breaker

CND63B900 - 900Amp Circuit Breaker

The CND63B900 Siemens SENTRON molded-case circuit breaker is a 900-Amp, 3-pole ND frame breaker used in large electrical distribution systems where steady, predictable protection is needed for higher-capacity loads. You’ll typically find this type of breaker in main service switchboards, feeder circuits, and industrial distribution panels operating on 480V and 600V three-phase systems.

This unit uses a thermal-magnetic trip system, which provides straightforward protection against overloads and short circuits. It also includes a current-limiting design that helps manage fault conditions within its rated interrupting capacity. With interrupting ratings of 100 kA at 480V and 65 kA at 600V, it is intended for systems where fault levels must be properly accounted for in the design and installation.

At its core, this breaker is about keeping established Siemens electrical systems running as designed—with consistent fit, consistent function, and reliable compatibility within ND frame installations.

Key Features and Benefits

• 900 Amp, 3-pole Siemens ND frame molded case circuit breaker
• Designed for Siemens SENTRON power distribution systems
• Thermal-magnetic trip unit for overload and short-circuit protection
• Current-limiting design for controlled fault response
• High interrupting ratings: 100kA @ 480V, 65kA @ 600V
• Includes line and load side lugs (TA4N8500)
• Accepts 250–500 kcmil Cu/Al conductors
• 40°C rated operating temperature
• 3-pole simultaneous disconnect for three-phase systems
• Used in feeder and main service applications
• Built for compatibility with existing Siemens ND frame systems

Technical Specifications

• Catalog Number: CND63B900
• Product Type: Molded Case Circuit Breaker
• Frame Type: ND Frame
• Amperage Rating: 900 Amps
• Poles: 3
• Voltage Rating: 600V AC
• Interrupting Rating: 100kA @ 480V; 65kA @ 600V
• Trip Unit: Thermal-Magnetic
• Temperature Rating: 40°C
• Conductor Range: 250–500 kcmil Cu/Al
• Included: Line and load side lugs (TA4N8500)
• Dimensions: 9 in W x 16 in H x 6 in D
• Net Weight: 55.501 lb

Material Compliance and Certifications

The CND63B900 Siemens SENTRON breaker is designed in accordance with the UL 489 and IEC 60947-2 standards for molded-case circuit breakers used in industrial and commercial electrical distribution systems. It is intended for installation in compatible Siemens ND frame assemblies and should be installed by qualified electrical personnel in accordance with applicable electrical codes and manufacturer guidelines.

Where It Works Best

• Industrial power distribution systems
• Siemens SENTRON switchboards and panelboards
• Main service and feeder circuit protection
• Large commercial electrical facilities
• 480V and 600V three-phase systems
• High-load electrical distribution networks
• Maintenance and replacement in existing ND frame systems
• Engineered electrical infrastructure requiring coordinated protection