What the 320 A / 200 kA rating means for your motor circuit
The C40R32M320 is a Schneider Electric ComPacT NSX400R circuit breaker — a 3-pole, 320 A frame with a MicroLogic 2.3 M electronic trip unit, purpose-built for motor protection. The trip unit offers L (long-time overload), So (short-time short-circuit with fixed delay), and I (instantaneous) protection curves, with selectable motor tripping classes 5, 10, and 20 to match the thermal withstand of your motor during start-up.
Mounting and integration — backplate, front connections, IP40
Both line and load connections are front-accessible — no rear bus work required, which simplifies panel wiring and retrofit. IP40 enclosure protection means it keeps out tools and wires over 1 mm but is not sealed against moisture — install in a dry indoor cabinet. IK07 impact rating handles light mechanical shock during maintenance.
Lifecycle and compliance — current production, IEC 60947-2
The C40R32M320 carries a current lifecycle stage — Schneider continues to manufacture this order code. No earth-leakage protection is integrated; if ground-fault detection is needed, pair it with an external Vigi module or residual-current relay.
Durability and thermal memory — what the cycle counts tell a maintenance planner
Mechanical durability is rated at 15,000 cycles; electrical durability varies by load: 12,000 cycles at 440 V at half rated current, 6,000 cycles at full 440 V In, and 3,000 cycles at 690 V In. For a motor-starting application with frequent starts, the lower electrical endurance at full voltage matters — plan inspection intervals around the 6,000-cycle mark at 440 V.