Siemens 5SY4310-6 — 3-pole B-curve MCB for panel and machine builds
It carries a 10 kA breaking capacity per EN 60898-1 and a 20 kA rating per IEC 60947-2, with a DC breaking capacity of 15 kA at 60 V per IEC 60947-2. It mounts in any position and accepts supply from either end — top or bottom feed — which simplifies busbar routing in dense panels. The IP20 rating applies with conductors connected; the housing is sealable for tamper-proofing in field installations.
Breaking capacity and dual-standard compliance
This MCB is certified to IEC / EN 60898-1 (10 kA) and IEC / EN 60947-2 (20 kA), plus UL 1077 / CSA C22.2 No.235 (5 kA). The dual rating means it qualifies as a circuit breaker for branch-circuit protection under IEC 60947-2 in industrial installations, while also meeting the residential and commercial standard EN 60898-1. The UL 1077 listing covers supplementary protection in North American panels — not primary branch-circuit protection per UL 489, so verify the application before specifying for US code-bound jobs. The DC rating of 15 kA at 60 V (72 V max) covers battery-bank and DC-bus protection in UPS or solar combiner applications.
Environmental range and derating
The 5SY4310-6 operates from -40 °C to 75 °C, with a derating curve tied to relative humidity: max 95% RH up to 55 °C, dropping to 55% RH at 70 °C and 35% RH at 75 °C. In a sealed, non-ventilated enclosure near a heat source (drive, transformer), the internal temperature can exceed the ambient derating threshold — plan for forced ventilation or a higher-rated frame if the panel runs hot and humid.