Commissioning engineer's spec recap
The Siemens SENTRON 3VA1150-3EF36-0BC0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection duty. At 40 °C it carries a full 50 A continuous; the thermal curve holds flat through 50 °C, then derates to 45 A at 70 °C. Breaking capacity lands at 75.6 kA at 240 V, 52.5 kA at 415 V, and 11.9 kA at 690 V — sufficient for most industrial distribution panels fed from a transformer secondary. This unit ships with an undervoltage release (UVR) and two HQ auxiliary switches integrated. The UVR trips the breaker when control voltage drops, a standard requirement for emergency-stop chains and safety circuits. The auxiliary switches provide status feedback to a PLC or annunciator panel without external interposing relays. Insulation voltage is rated at 800 V, giving headroom for 690 V line-to-line systems. The breaker is designed for line protection — not motor protection — so it lacks adjustable thermal or magnetic trip units; it's a fixed-trip MCCB for feeder and distribution applications.
Panel integration and footprint
The breaker occupies a 76.2 mm wide by 130 mm tall by 70 mm deep footprint — a standard 3-pole MCCB envelope that fits most DIN-rail or panel-mount backplates. The 70 mm depth is shallow enough for shallow enclosures; verify gland-plate clearance if the breaker is mounted near the rear wall. Maximum power dissipation is 17.1 W at full rated load. In a sealed, uncooled enclosure this heat must be factored into the thermal budget — adjacent devices may need derating if airflow is restricted.
Environmental and compliance notes
Operating temperature range spans -25 °C to +70 °C; storage range extends from -40 °C to +80 °C. This covers most indoor industrial environments and unheated warehouses. The part is not rated for marine or offshore use without additional type-approval documentation — no DNV, ABS, or Lloyd's certificate is listed in the standard spec set.