Siemens Circuit breaker, 1-pole, D-Curve, 4A, 10kA Part number 5SY4104-8

Product Overview

The Siemens 5SY4104-8 is a single-pole miniature circuit breaker (MCB) from the SENTRON 5SY4 series, rated at 4 A with a D-curve tripping characteristic. It provides dependable overload and short-circuit protection for final circuits in residential, commercial, and industrial installations. Compact and durable, it features a 10 kA breaking capacity at 230/400 V AC, 18 mm modular width, and simple DIN-rail mounting, making it ideal for space-constrained panels.

Key Features

• Rated Current: 4 A
• Poles: 1 (single-pole switching)
• Trip Curve: D-curve — handles high inrush loads such as motors and transformers
• Breaking Capacity: 10 kA at 230/400 V AC (EN 60898) / up to 35 kA (IEC 60947-2)
• Operating Voltage: 230/400 V AC | 72 V DC (per pole)
• Installation Depth: 70 mm for DIN-rail or panel mounting
• Width: 18 mm (1 module width)
• Protection Class: IP20 with connected conductors
• Terminals: Screw-type terminals for solid or stranded conductors up to 35 mm²
• Mechanical Endurance: Approx. 10,000 switching operations

Technical Specifications

• Product Series: SENTRON 5SY4 Miniature Circuit Breakers
• Article Number: 5SY4104-8
• Number of Poles: 1 (P)
• Rated Current (In): 4 A (at 35 °C)
• Rated Operational Voltage (Ue): 230/400 V AC
• Rated Insulation Voltage (Ui): 440 V AC
• Rated Short-Circuit Breaking Capacity (Icn): 10 kA (EN 60898)
• Rated Ultimate Breaking Capacity (Icu): 35 kA (IEC 60947-2)
• Power Loss per Pole: Approx. 1.2 W
• Conductor Size Range: 0.75 – 35 mm² (solid or stranded)
• Operating Temperature Range: –40 °C to +70 °C (with derating)
• Protection Class: IP20 (front and terminals)
• Dimensions (W × H × D): 18 mm × 90 mm × 70 mm
• Weight: Approx. 0.15 kg
• Mounting: 35 mm DIN-rail (EN 60715)
• Country of Origin: Germany

Compliance & Certifications

• Standards: EN 60898-1 (for residential/commercial use), IEC 60947-2 (for industrial applications)
• CE Marking: Conforms to EU Low Voltage and Machinery Directives
• UL / CSA Approval: Compliant as a supplementary protector
• RoHS Compliant: Free from hazardous substances since 2006
• WEEE Directive: EU take-back obligations apply

Applications

Ideal for branch-circuit protection in residential, commercial, and industrial distribution boards, control panels, and machinery. Commonly used for lighting, socket circuits, and auxiliary loads requiring a D-curve breaker to handle equipment with high inrush currents (such as motors and transformers).