Siemens 5SY4120-7 Miniature Circuit Breaker 1P C20A 10kA SENTRON

The Siemens 5SY4120-7 (MLFB: 5SY4120-7) is a 1-pole SENTRON miniature circuit breaker rated at 20 A with a tripping characteristic class C and a breaking capacity of 10 kA per EN 60898. Designed for both infrastructure and industry applications, it provides reliable overcurrent and short-circuit protection in AC and DC systems.

Technical specifications:

• MLFB: 5SY4120-7
• Manufacturer: Siemens
• Product line: SENTRON
• Number of poles: 1 (1P)
• Tripping characteristic: Class C
• Rated current: 20 A
• Rated voltage (AC): 230 V (single-phase), 400 V (multi-phase)
• Insulation voltage (Ui): 440 V AC
• DC operating voltage: max 72 V
• Breaking capacity: 10 kA (EN 60898), 20 kA (IEC 60947-2)
• Energy limitation class: 3
• IP rating: IP20 (with connected conductors)
• Overvoltage category: 3
• Degree of pollution: 3
• Conductor cross-section: 0.75-35 mm² (solid/stranded), 0.75-25 mm² (finely stranded)
• Tightening torque: 2.5-3.5 N·m
• Dimensions (WxHxD): 18 x 90 x 76 mm, installation depth 70 mm
• Weight: 153 g
• Operating temperature: -40 °C to +70 °C
• Mounting: DIN rail, any position
• Frequency: 50/60 Hz
• Standards: IEC/EN 60898-1, IEC/EN 60947-2, UL 1077

Features and benefits:

• Touch protection with combined top and bottom terminals for safe wiring
• Halogen-free, silicon-free, and sealable construction
• Suitable as main switch per EN 60204-1
• Supplementary devices can be installed for extended functionality
• Wide operating temperature range: -40 °C to +70 °C
• Mechanical service life of 10,000 operating cycles

Applications:

• Overcurrent and short-circuit protection in residential and commercial distribution boards
• Protection of final circuits in industrial control panels
• Use as a main switch in machinery per EN 60204-1
• Infrastructure and industry installations requiring 230/400 V AC protection

Compliant with IEC/EN 60898-1 and IEC/EN 60947-2. Part of the Siemens SENTRON range.

Also known as: Siemens 5SY4120-7, SENTRON MCB 1P C20A 10kA.