MCCB for line protection with thermal-magnetic trip
The Siemens SENTRON 3VA1220-5GF42-0KH0 is a 4-pole molded case circuit breaker (MCCB) rated for 200 A continuous current (Iu) at 40 °C, configured for line protection with a TM240 thermal-magnetic overcurrent release. Its interrupting capacity reaches 187 kA at 240 V, 121 kA at 415 V, 36 kA at 440 V, and 17 kA at 690 V — so it handles high-fault-current scenarios downstream of a transformer or in a main distribution board without cascading upstream. The 800 V rated insulation voltage (Ui) gives headroom for 690 V line-to-line systems.
Thermal derating and panel integration
The breaker holds 200 A up to 50 °C ambient, then derates linearly to 176 A at 70 °C. That means in a warm enclosure — say a non-ventilated panel near a furnace line — you size the load at 176 A, not the nameplate 200 A. The 70 mm depth and 140 mm width fit standard SENTRON 3VA mounting footprints; the IP40 front-face protection keeps dust out of the trip unit and auxiliary compartments in a clean indoor panel.
Built-in accessories and trip configuration
Factory-fitted with a shunt trip release (STL) for remote tripping and a 2-auxiliary-switch-plus-1-trip-alarm-switch HQ contact block for status feedback to a PLC or annunciator. The TM240 thermal-magnetic trip unit is fixed — no interchangeable rating plugs — so the 200 A frame is the trip rating. The integrated auxiliary trip order code is 3VA9688-0BL33, which is the spare/replacement part number for the shunt trip assembly. 100 % N-conductor protection is included, meaning the neutral pole is fully rated and trips with the phase poles.