High-fault MCCB with integrated shunt trip
The ETU340 electronic trip unit with ELISA LI characteristic gives adjustable overload protection (Ir = 200–500 A) and a fixed short-circuit pickup of 14 × In. That 14× multiplier means instantaneous trip at 7000 A for the 500 A rating — a deliberate coordination band for motor-starting inrush or transformer energization.
Factory-fitted accessories
This unit ships with a left-side shunt trip rated 208–277 V AC 50/60 Hz and 220–250 V DC, plus one auxiliary switch (changeover). The shunt trip lets a remote relay or safety PLC open the breaker without a manual handle pull — common in emergency-stop chains or undervoltage release schemes. The auxiliary switch reports breaker position back to the control system. The nut keeper kit (included per the description) retains the lug nuts during high-vibration busbar connections — a detail that saves a panel-builder chasing dropped hardware inside a live board.