It is the motor-protection variant of the 3VA2 frame, meaning the trip curve and release logic are tailored for motor starting inrush and thermal overload — not for general distribution.
Current ratings and thermal derating
Above that, the ETU350M release derates: 60.48 A at 55 °C, 59.22 A at 60 °C, 57.96 A at 65 °C, and 56.7 A at 70 °C. In a sealed, uncooled enclosure — typical for motor control centers in hot plant environments — that derating matters.
Trip unit and protection features
The ETU350M is a microprocessor-based release providing adjustable overload (Ir), short-time (Isd), and instantaneous (Ii) protection, plus ground-fault alarm (not trip — this unit ships without ground-fault monitoring). Phase failure detection is included, which is critical for motor protection: losing one phase on a running motor draws locked-rotor current on the remaining phases, and the release catches that imbalance. The breaker also carries a shunt trip (STL) auxiliary release for remote tripping, plus a 2+2 auxiliary contact block (2 auxiliary switches + 1 trip alarm + 1 electrical alarm switch HQ). No undervoltage release or communication module is fitted on this variant.
Physical dimensions and panel fit
Depth of 86 mm includes the rotary handle and arc-chamber protrusion; clearance behind the panel for the rear terminals should allow at least 100 mm for cable bending radius.