Siemens 5SL6340-7 3-Pole 40 A 400 V C-Curve Miniature Circuit Breaker, 6 kA Breaking Capacity, DIN Rail Mount

In commercial and industrial electrical distribution boards, the Siemens 5SL6340-7 miniature circuit breaker (MCB) reliably protects three-phase circuits against overload and short-circuit currents. With a rated current of 40 A and a C tripping characteristic, it is well-suited for motor feeders, lighting circuits, and general power distribution where moderate inrush currents are expected.

Key specifications

• Number of poles: 3
• Tripping characteristic: C
• Rated current (In): 40 A
• Rated voltage (Un): 400 V AC
• Rated switching capacity (Icn): 6 kA according to EN 60898-1
• Frequency: 50/60 Hz
• Mounting type: DIN rail (35 mm)
• Degree of protection: IP20 (terminals), IP40 (with connected conductors)
• Terminal type: Screw terminals
• Max. conductor cross-section (solid): 35 mm²
• Max. conductor cross-section (stranded): 25 mm²
• Operating temperature: -25 to +45 °C
• Electrical endurance: 10,000 switching cycles
• Mechanical endurance: 20,000 switching cycles
• Standard: IEC/EN 60898-1
• Installation depth: 70 mm
• Number of width units (modules): 3

Why choose it

The Siemens 5SL series is known for its robust construction and reliable protection. This 3-pole MCB offers a high breaking capacity of 6 kA, ensuring safety in demanding applications. Its screw terminals accommodate large conductor cross-sections, simplifying installation. The device meets international standards, guaranteeing compatibility and performance.

Ideal use cases

• Protection of three-phase motors and pumps in industrial control panels
• Distribution boards in commercial buildings, workshops, and infrastructure facilities
• Circuits with moderate inrush currents, such as lighting banks and HVAC systems

Good to know

The C tripping characteristic trips instantaneously at 5 to 10 times the rated current, making it ideal for circuits with moderate surge currents. The breaker occupies three modules (width units) on a standard 35 mm DIN rail. It is suitable for use in ambient temperatures from -25 °C to +45 °C, ensuring reliable operation in a wide range of environments.