Rated for 400 A continuous, 187 kA interrupting at 240 V
The Siemens SENTRON 3VA2340-5HN42-0BC0 is a 4-pole molded case circuit breaker rated for 400 A continuous current, with an interrupting capacity of 187 kA at 240 V AC and 121 kA at 415 V AC. That interrupting rating at 415 V means it handles high-fault utility or transformer-fed downstream panels without cascading — the breaker clears the fault before upstream devices need to act. At 690 V the rating drops to 7.5 kA, so it's not a primary choice for 690 V distribution unless the available fault current is known to be low. Thermal derating is flat at 400 A from 40 °C up to 50 °C, then steps down to 385 A at 55 °C and 340 A at 70 °C. If the panel ambient runs above 50 °C, you lose 60 A off the top — factor that into the load schedule.
Line protection with undervoltage release and auxiliary switches
This MCCB is designed for line protection — it's not a motor-protective breaker with integrated overload class. It ships with an undervoltage release (UVR) and two auxiliary switches (HQ type). The UVR trips the breaker when control voltage drops below a threshold, which is standard for emergency-stop or undervoltage-coordination schemes. The auxiliary switches provide status feedback to a PLC or indication lamp. The basic switch (the thermal-magnetic trip unit) is order code 3VA2340-5HN42-0AA0 — that's the replaceable core if the trip unit fails. No communication function, no ground-fault monitoring on this variant.
Dimensions and panel fit
Mounting footprint: 184 mm wide, 248 mm tall, 110 mm deep. That 184 mm width for a 4-pole frame is standard for 400 A MCCBs in the SENTRON 3VA platform — it occupies three full 18 mm module positions plus some overhang. Plan for a 110 mm depth behind the panel door to clear the arc-chamber vents and rear terminals.