Motor protection breaker with ETU350M trip unit
The Siemens 3VA2110-5MN36-0BA0 is a 3-pole IEC frame 160 circuit breaker rated for motor protection, fitted with an ETU350M electronic trip unit offering LSI protection (long-time, short-time, instantaneous). The breaker carries a breaking capacity of Icu=55kA at 415V, which means it can safely interrupt fault currents up to that level without upstream cascading — critical for high-fault panels where coordination with downstream devices is required.
Protection settings and release
Overload protection (Ir) is adjustable from 40A to 100A, matching the In=100A frame rating. Short-circuit protection (Isd) is set between 3 and 15 times Ir, and the instantaneous pickup (Ii) is fixed at 15 times In. The undervoltage release (UVR) operates on 24V DC — if the control voltage drops, the breaker trips, which is standard practice for emergency-stop or safety-related disconnection circuits.