The ETU550 electronic trip unit gives adjustable long-time, short-time, and instantaneous protection curves, plus ground-fault alarm capability. Communication function is built in, which means it talks to a BMS or PLC without an add-on module.
Power loss is only 0.6 W, so heat buildup in a crowded panel is negligible.
Trip unit and protection capabilities
The ETU550 is an electronic release with LSIG protection — long-time, short-time, instantaneous, and ground-fault. That's more granular than a thermal-magnetic breaker, so you can coordinate with downstream devices on a selective system. The ground-fault monitoring version is listed as 'Without' on this order code, meaning the base unit doesn't include internal GF sensing; if you need integral ground-fault, the ETU550 platform supports it via a different variant. The optional motor drive lets you add remote open/close for automated transfer schemes.