Motor protection breaker with ETU550M LSI trip
The Siemens 3VA2325-5MP32-0KC0 is a 3-pole motor protection circuit breaker from the 3VA2 series, IEC frame 400. It carries an In of 250 A and an ETU550M LSI trip unit with overload protection adjustable from 100 A to 250 A and short-circuit protection Isd = 1.2…15 x In, Ii = 3…15 x In.
The ETU550M LSI trip gives you separate adjustment of long-time (overload), short-time, and instantaneous pickup, which is what you need for motor coordination: set Ir to match the motor FLA, then tune Isd and Ii to ride through starting inrush while still protecting the cable. The shunt trip left (208-277 V AC / 220-250 V DC) allows remote tripping from an E-stop or safety PLC, and the two auxiliary changeover contacts provide status feedback to the control system.
Deployment context
This breaker mounts in a standard IEC panel on a busbar connection — typical for motor control centers (MCCs) or distribution boards feeding pumps, fans, compressors, and conveyors. The 3-pole form factor fits a 3-phase motor branch; the busbar connection means it lands directly on a horizontal or vertical busbar system, not on cable lugs. The auxiliary switches and shunt trip make it ready for integration into a safety circuit or remote monitoring scheme.