Siemens NMG3B800 Circuit Breaker, 800A, 3-Pole

Introducing the Siemens NMG3B800 circuit breaker — a purpose-built solution for industrial electrical service, maintenance, and replacement projects. This 3-pole, 800 A unit sits squarely in the VL-series family, designed to integrate with existing VL-series panels where the part number matches your application.

Designed for demanding environments, the NMG3B800 provides decisive protection for high-current circuits, helping prevent equipment damage and unplanned downtime. By aligning to Siemens' VL series, it offers consistent performance characteristics, predictable tripping behavior, and straightforward field replacement within compatible assemblies.

Key specifications

• Manufacturer: Siemens
• Series: VL
• Part Number: NMG3B800
• Product Type: Circuit Breaker
• Amperage: 800 A
• Poles: 3

Why it matters

Industrial facilities rely on robust protection for feeders and motors. The 3-pole configuration ensures coordinated shutdown across three phases, helping maintain balance and reducing the risk of partial circuit damage during faults. With an 800 A rating, this breaker is suited for large feeders and main-distribution circuits in manufacturing floors or heavy equipment installations.

Use cases

• Protection for large motor drives and feeders in production lines
• Replacement part for VL-series panels that require the NMG3B800
• Emergency isolation of three-phase circuits during maintenance

Compatibility and verification

To ensure a correct fit, verify the part number and application requirements. Use the NMG3B800 part number as the primary compatibility signal and confirm panel, bus, and mounting compatibility within VL-series infrastructure.

Need help matching a part number or confirming compatibility? Message us and we'll help.