Siemens Surge protector, Din rail mount, 3-phase, 25kA Part number 5SD7444-1

Product Overview

The Siemens 5SD7444-1 is a combination surge arrester (type 1 + 2) in requirement class B + C, designed for low-voltage power distribution systems. It supports TN-S and TT networks, features a 4-pole (3 + N/PE) configuration and includes plug-in protective modules with remote signalling capability.

Key Features

• Surge protection device (SPD), combination arrester type 1 + 2 (classes I + II)
• Rated continuous operating voltage Uc: up to 350 V AC
• 4-pole design (3 phases + neutral/PE) for TN-S and TT systems
• Plug-in protective modules; remote display and remote signalling contact included
• DIN-rail mounting on TH35 profile for easy installation

Technical Specifications

• Product Series: Siemens SENTRON SPD Accessories
• Article Number: 5SD7444-1
• Standard(s): IEC 61643-11:2011 / EN 61643-11:2012
• SPD Classification: Test Class I (Type 1): Yes; Test Class II (Type 2): Yes; Test Class III (Type 3): No
• Distribution Systems Supported: TN-S, TT
• Continuous Operating Voltage (U c): Maximum 350 V AC
• Lightning Current Peak Value (10/350 µs): L-N: 25 kA; L-PE: 25 kA; N-PE: 100 kA
• Nominal Discharge Current (8/20 µs): L-(PE)N: 25 kA; L-PE: 25 kA; N-PE: 100 kA
• Protection Level (Up-voltage): L-N ≤1.5 kV; L-PE ≤2.2 kV; N-PE ≤1.5 kV
• Dimensions (W × H × D): ~142.8 mm × 95 mm × 71.5 mm
• Net Weight: Approx. 1.372 kg
• Ambient Operating Temperature: -40 °C to +80 °C
• Connection Type: Screw terminals; stripped length 18 mm; M5 thread; conductor cross-section rigid 2.5 … 35 mm²; fine-stranded 2.5 … 25 mm²
• Remote Signalling Contact: Optical/PDT contact, AC 12…250 V, 10 mA…1 A
• Pollution Degree: 2; Protection Class at terminals: IP20

Compliance & Certifications

• Complies with IEC/EN standards for surge protective devices in low-voltage systems
• Manufactured under Siemens quality standards, RoHS-compliant, suitable for industrial distribution systems

Applications

The Siemens 5SD7444-1 is ideal for installation in low-voltage power distribution panels where comprehensive surge protection (both type 1 and type 2) is required. It is well-suited for TN-S and TT systems in commercial, industrial and infrastructure settings, offering high protection levels, remote signalling capability and plug-in module convenience.