Onesto 3P 3kA MCB C-Curve DIN

• The Onesto Triple Pole (3P) 3kA C-Curve Miniature Circuit Breaker (MCB) series is engineered to provide essential protection for three-phase electrical circuits in residential and light commercial applications where lower fault current levels are anticipated.
• These MCBs are designed to safeguard against overcurrents and short circuits, ensuring simultaneous disconnection of all three phases. Featuring a C-Curve tripping characteristic, they are suitable for general-purpose three-phase loads.
• Compliant with IEC60898-1 standards, this range offers a cost-effective and reliable solution for basic three-phase circuit protection.

Features

• Triple Pole (3P) configuration for complete three-phase circuit protection.
• Rated short-circuit breaking capacity (Icu & Ics): 3kA.
• C-Curve tripping characteristic: Suitable for general purpose, resistive, and moderately inductive three-phase loads.
• Comprehensive range of current ratings: 1A, 2A, 3A, 4A, 6A, 10A, 16A, 20A, 25A, 32A, 40A, 50A, 63A.
• Thermo-magnetic trip mechanism for effective overload and short-circuit protection.
• Standard Compliance: IEC60898-1.
• Rated Operational Voltage (Ue): 415V AC (for 3P).
• Rated Insulation Voltage (Ui): 415V.
• Rated Impulse Withstand Voltage (Uimp): 4kV.
• Protection Index: IP20.
• Designed for easy DIN rail mounting.

Benefits

• Three-Phase Protection: Ensures simultaneous disconnection of all three phases, critical for protecting three-phase equipment from damage under fault conditions.
• Reliable Safety for Low Fault Levels: 3kA breaking capacity provides adequate protection for installations with confirmed lower prospective short circuit currents.
• Versatile for General Loads: C-Curve characteristic is suitable for a variety of common three-phase loads, minimizing nuisance tripping while offering effective protection.
• Dependable Dual Protection: The thermo-magnetic mechanism offers precise protection against both sustained thermal overloads and instantaneous magnetic trips during short circuits.
• International Standard Adherence: Compliance with IEC60898-1 ensures a recognized level of quality, safety, and performance.
• Cost-Effective Solution: Provides essential protection for three-phase circuits where a higher breaking capacity is not required, offering good value.
• Simplified Installation: Standard DIN rail compatibility allows for quick and secure mounting in distribution boards and control panels.

In-Depth Technical Specifications

Ideal Use

• Protecting light three-phase loads in residential settings (e.g., small pumps, hobbyist workshop equipment).
• Small commercial installations with limited three-phase loads and confirmed low fault current levels.
• Cost-sensitive projects where the prospective short circuit current (PSCC) is safely below 3kA.
• Training and educational setups where basic three-phase protection is demonstrated.

Tips

• Verify Fault Level Absolutely: The most critical consideration is to ensure the installation's prospective short circuit current (PSCC) is reliably below 3kA. Using a 3kA MCB in an installation with a higher PSCC is dangerous and non-compliant. If in any doubt, or if the PSCC is higher, a 6kA or 10kA MCB must be used.
• Load Characteristics: Ensure the C-Curve is appropriate for the connected three-phase load. While suitable for general loads, very high inrush currents might require a D-Curve (though D-Curves are less common in 3kA ratings).
• Professional Installation is Key: Installation of any three-phase device must be carried out by a qualified and licensed electrician who can confirm the suitability of the 3kA rating for the specific installation.
• Secure Connections: Ensure all three-phase terminal connections are tightened to the manufacturer's specified torque values.
• Appropriate Enclosure: While IP20 rated, these MCBs should be housed within a suitable electrical enclosure that provides the necessary environmental protection for the installation site.