The Siemens SENTRON 5SM9345-6KK is a 4-pole residual current unit (RC unit) rated at 63 A with a 30 mA trip threshold, type A, for 400 V AC systems. It sits in the 5SM9 design family — an electronic instantaneous-trip device for branch-circuit protection where earth leakage must be detected and interrupted fast.
Current derating across temperature
At 40 °C and 45 °C the unit carries its full 58.59 A without derating. Above that it steps down: 56.7 A at 50 °C, 54.81 A at 55 °C, 53.55 A at 60 °C, 52.29 A at 65 °C, and 50.4 A at 70 °C. For a panel that runs warm — say near a transformer or high-density bus — the 50 °C figure is the one to size against.
Lifecycle and sourcing
The 5SM9345-6KK is listed as current-production (lifecycle stage: current). Sourced to order through independent distribution; pricing and availability confirmed at quote time against an RFQ.