SENTRON 3VM1225-3EE42-0AA0 — 250 A MCCB, 4-Pole, TM220 Release
The Siemens 3VM1225-3EE42-0AA0 is a SENTRON molded case circuit breaker (MCCB) rated for line protection in distribution panels. It carries 250 A continuous current (Iu) across ambient temperatures from 40 °C to 50 °C, derating to 223 A at 70 °C. The TM220 thermal-magnetic release provides fixed thermal and magnetic trip thresholds — no adjustment dials for Ir or Ii. This suits applications where coordination studies set fixed pickup values and you don't want field-adjustable settings drifting. Four-pole construction covers three-phase-plus-neutral or three-phase with switched neutral, common in North American and European panel builds where the neutral must be isolated or protected.
Interrupting Capacity Across Voltages
Rated short-circuit breaking capacity (Icu) varies with system voltage: 76 kA at 240 V AC, 53 kA at 415 V, 32 kA at 440 V, and 11.9 kA at 500 V AC. The 53 kA at 415 V is the figure most European industrial installations need for transformer-fed fault levels. Rated insulation voltage Ui is 690 V, so the breaker is rated for 690 V line-to-line systems even though the interrupting ratings are given at lower voltages. The TM220 release is not voltage-sensitive — the same trip unit works across the voltage range.
Panel Integration Notes
Front face protection is IP40 — suitable for enclosed distribution boards where tools or fingers might contact the front but not for washdown environments. No ground-fault monitoring module, no motor drive, and no N-conductor protection built in; these are external add-ons if required. Maximum power loss is 57 W at rated current — account for this in thermal calculations inside a sealed enclosure, especially when grouping multiple breakers.