What it is and what it handles
The 5SY4403-7: Handles -40 to 75 °C ambient. IP20 with conductors connected. Pollution degree 3, overvoltage category III — fine for main switchboards and industrial panels.
Compliance and build notes
Compliance covers IEC/EN 60898-1, IEC/EN 60947-2, and UL1077. Halogen-free and silicon-free construction. That nameplate carries real certification paperwork, not just a marketing stamp. Energy limitation class 3. Sealable — good for revenue-meter applications or panel lockout procedures.
Mounting and wiring
Mounts in any position. Four modular width units (72 mm, 76 mm deep, 90 mm tall). Quick-assembly system for DIN rail. Top and bottom combined terminals. Neutral conductor switching is not separate — the 4-pole design handles all four poles, so verify your neutral switching requirement. Power feed position is arbitrary; no preferred side.