Motor Protection MCCB with Flat Derating to 70 °C
The Siemens SENTRON 3VA2163-7MN36-0BL0 is a 3-pole molded case circuit breaker (MCCB) rated at 63 A continuous current, specifically configured as the motor protection variant. It carries the ETU350M electronic trip unit, which provides adjustable overload and short-circuit protection curves matched to motor starting characteristics. The breaker maintains its full 63 A rating across the entire operating temperature range from 40 °C through 70 °C — no derating needed up to the maximum ambient of 70 °C, which simplifies panel sizing in warm enclosures. Breaking capacity is substantial: 330 kA at 240 V, 242 kA at 415 V and 440 V, 187 kA at 500 V, and 3.7 kA at 690 V. That 330 kA figure at 240 V covers high-fault scenarios common in industrial distribution — useful when this breaker sits downstream of a large transformer or in a switchboard with high available fault current.
Panel Fit and Auxiliary Contact Configuration
Footprint: 105 mm wide, 181 mm tall, 86 mm deep. The 105 mm width is standard for a 3-pole 63 A frame in the 3VA series — it occupies three 35 mm DIN module positions if panel-mounted, or bolts directly into a mounting plate. Depth of 86 mm leaves clearance behind the panel for wiring and the auxiliary contact block. Comes equipped with 2 auxiliary switches, 1 trip alarm switch, and 1 electrical alarm switch (HQ configuration). That gives four signal outputs for status feedback to a PLC or annunciator — enough to cover open/closed, trip, and a separate electrical alarm without adding an external relay.
Protection and Release Features
Includes an undervoltage release and phase failure detection as standard — both critical for motor protection applications where a phase loss can single-phase a motor and cause winding damage. The undervoltage release trips the breaker when supply voltage drops below a threshold, preventing automatic restart after a dip. No ground-fault monitoring on this variant, and no communication function; it's a standalone protection device. Rated insulation voltage (Ui) is 800 V, which covers 690 V systems with margin. Power loss at rated current is 6.5 W maximum — modest for a 63 A MCCB, so ventilation requirements in the enclosure are minimal.