Siemens Miniature circuit breaker, 3-pole, D, D=70mm, 400V, 15kA, 4A Part number 5SY7304-8

Product Overview

The Siemens 5SY7304-8 is a 3-pole miniature circuit breaker (MCB) from the SENTRON 5SY7 series. It is rated at 4 A with a D-curve tripping characteristic, suitable for circuits with high inrush currents—and features a high breaking capacity of up to 15 kA under IEC 60898-1 and up to 40 kA under IEC 60947-2.

Key Features

• 3-pole design for three-phase circuit protection
• D-curve tripping characteristic ideal for inductive loads with high inrush currents
• Rated operational current: 4 A at 400 V AC
• High short-circuit breaking capacity: 15 kA (EN 60898) / up to 40 kA (IEC 60947-2)
• Compact width corresponding to 3 modular units, suitable for DIN-rail mounting

Technical Specifications

• Product Series: SENTRON 5SY7 Miniature Circuit Breakers
• Article Number: 5SY7304-8
• Number of Poles: 3 (3-pole)
• Tripping Characteristic: D-curve
• Rated Current (In): 4 A
• Rated Operational Voltage (Ue): 400 V AC
• Rated Insulation Voltage (Ui): 440 V AC
• Rated Impulse Withstand Voltage (Uimp): 4 kV
• Short-Circuit Breaking Capacity (Icn): 15 kA (EN 60898); 40 kA (IEC 60947-2)
• Width / Modular Units: 54 mm (~3 units)
• Depth (Installation): 70 mm
• Height: 90 mm
• Net Weight (Approx.): 0.452 kg
• Protection Class: IP20 (with connected conductors)
• Operating Ambient Temperature Range: –40 °C to +70 °C

Compliance & Certifications

• Complies with IEC/EN 60898-1 and IEC/EN 60947-2 standards for miniature circuit breakers
• Manufactured under Siemens SENTRON series quality standards

Applications

The Siemens 5SY7304-8 is designed for use in commercial and industrial electrical distribution panels where high inrush currents may be encountered—such as motors, transformers or capacitive loads—and where high breaking capacity is required. Its compact 3-module width and 3-pole design make it well suited for three-phase branch circuits requiring robust protection.