BG Bi-Directional MCB B Curve Single Pole 50A CUMB50

BG Fortress CUMB50 — 50A B Curve Single-Pole Bidirectional MCB (6kA, 1 Module)

The BG CUMB50 is a 50A B-curve, single-pole bidirectional MCB designed to provide robust overload and short-circuit protection for high-load domestic and light-commercial circuits. Its bidirectional capability ensures safe operation even where current may flow in either direction, making it suitable for installations incorporating solar PV, battery storage and other microgeneration systems.

Engineered with a compact 1-module (17.85mm) DIN-rail profile, the CUMB50 fits seamlessly into all BG consumer units and enclosures.

Reliable Circuit Protection for High-Demand Loads

The CUMB50 features a B-curve tripping characteristic, providing dependable protection for circuits with low inrush currents while avoiding nuisance tripping. With a 6kA breaking capacity, it ensures reliable fault interruption across a wide range of installations.

Typical applications include:

High-load radial circuits

Water heaters / immersion circuits

Electric heating systems

Small sub-mains and distribution feeds

Installer-Focused Design & Durability

Designed for fast, confident installation, the CUMB50 includes:

Positive contact status indication

DIN-rail 35mm mounting

Pozidrive screw terminals

Terminal capacity up to 25mm² for 32–55A models

Tested to withstand 4,000 electrical operations and 10,000 mechanical operations, it offers exceptional reliability throughout its service life.

Key Features of the BG Bi-Directional MCB 50A Include:

• 50A B-Curve Single-Pole MCB for High-Load Circuits
• Bidirectional Protection Suitable for PV & Back-Feed Capable Installations
• 6kA Breaking Capacity for Reliable Fault Interruption
• Compact 1-Module (17.85mm) DIN-Rail Design
• Positive Contact Status Indication for Installer Assurance
• PZ2 Screw Terminals with Up to 25mm² Cable Capacity
• Operating Temperature: -25°C to +40°C
• High Durability: 4,000 Electrical & 10,000 Mechanical Operations
• Compliant with IEC/EN 60898 Standards

View all BG MCBs

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