The HMB1 Series Residual Current Circuit Breaker is a high-sensitivity safety device designed to protect people and electrical installations against earth leakage faults. Operating in AC 50/60Hz networks, the HMB1 monitors the balance of current between the live and neutral conductors.

When a leakage current exceeds the rated sensitivity (due to insulation failure or accidental contact with live parts), the HMB1 trips instantly, cutting off the power supply in milliseconds. This provides a critical line of defense against fatal electric shocks and electrical fires caused by ground faults.

• High Sensitivity for Human Safety: Available in 30mA sensitivity—the international standard for personal protection—ensuring the power is cut before a shock becomes lethal.
• Rapid Fault Interruption: Features a high-speed electromagnetic trip mechanism that ensures a disconnection time of less than 0.1 seconds, far exceeding global safety requirements.
• Vibration & Nuisance Trip Resistance: Engineered with a filtered mechanism to prevent "nuisance tripping" caused by minor grid fluctuations or lightning-induced surges.
• Comprehensive Circuit Protection: The HMB1 combines current leakage sensing with standard overcurrent and short-circuit protection (when configured as an RCBO), consolidating your safety needs into one compact unit.
• Ergonomic "Test" Interface: Includes a prominent monthly test button to ensure the internal circuitry and trip mechanism are fully operational, providing peace of mind for end-users.

1. Residential Distribution: Mandatory protection for bathroom and kitchen circuits, outdoor sockets, and lighting.
2. Commercial Buildings: Safety backup for office workstations, retail showrooms, and hotel HVAC units.
3. Industrial Workshops: Protecting operators from leakage in damp environments or during the use of hand-held power tools.
4. Temporary Power: Essential for construction site distribution boxes where cables are subject to mechanical wear and tear.

• Compact DIN-Rail Mounting: Standard 18mm or 36mm widths allow for easy integration into existing distribution boards without major rewiring.
• Clear Fault Indication: Features a dedicated mechanical window that changes color when a trip is caused specifically by a leakage fault, helping electricians diagnose issues faster.
• Durable Enclosure: Manufactured from high-strength, flame-retardant polymers that maintain structural integrity even under high-temperature fault conditions.
• Global Market Ready: Fully CE certified and compliant with IEC/EN 61008-1, making it suitable for international electrical tenders and residential projects.

Q: Should I choose 30mA or 100mA sensitivity?

A: 30mA is required for general personal protection (protection against direct contact). 100mA or 300mA is typically used for fire protection and equipment safeguarding where higher leakage is expected (protection against indirect contact).

Q: Does the HMB1 protect against short circuits?

A: Standard RCCBs protect only against earth leakage. If you require overcurrent and short-circuit protection in the same unit, ensure you select the RCBO (Residual Current Breaker with Overcurrent) version of the HMB1.

Q: Can it be used in a 3-Phase system?

A: Yes, the HMB1 is available in 4-pole configurations to provide comprehensive leakage protection for 3-phase machinery and balanced/unbalanced industrial loads.