MCCB for high-fault panels — 400 A continuous, 330 kA at 240 V
The Siemens SENTRON 3VA2340-7HN32-0JH0 is a 3-pole molded case circuit breaker rated for 400 A continuous current (Iu) with a 330 kA interrupting capacity at 240 V — that figure drops to 242 kA at 415 V and 52.5 kA at 690 V, so the SCCR headroom depends on your system voltage. It ships with the ETU350 electronic trip unit, a shunt trip (STL) auxiliary release, and a 2+1 HQ auxiliary contact block (two auxiliary switches plus one trip alarm). The line-protection version means it's configured for feeder and main breaker duty, not motor protection. Rated insulation voltage is 800 V, and the breaker carries a maximum power loss of 96 W at full load — a number to factor into enclosure thermal calculations, especially if the panel is tightly packed. The operating temperature range is -25 °C to 70 °C, with derating starting at 55 °C (385 A at 55 °C, down to 340 A at 70 °C). Storage range is wider: -40 °C to 80 °C.
Integration — panel fit and auxiliary wiring
The breaker occupies 138 mm width, 248 mm height, and 110 mm depth — a standard SENTRON 3VA frame size for the 400 A class. It mounts directly to a mounting plate or DIN rail via the base; the 3-pole construction leaves the neutral pole external if needed. The auxiliary contact block (2+1 HQ) and the shunt trip (STL) are factory-integrated, so no field-assembly of those accessories is required — the order code 3VA2340-7HN32-0JH0 already includes them. The trip indicator and voltage trigger are present, which simplifies fault diagnostics during commissioning.
Selectivity and coordination — what the ratings mean for the panel designer
The 330 kA breaking capacity at 240 V is the headline number, but the real-world selectivity study uses the 242 kA at 415 V or the 52.5 kA at 690 V — that's the value for a 400 V or 690 V distribution board. The ETU350 trip unit offers adjustable long-time, short-time, instantaneous, and ground-fault protection (though this variant ships without ground-fault monitoring). For a main breaker in a high-fault industrial panel, the 400 A continuous rating with 242 kA SCCR at 415 V covers most common LV switchgear applications. The 15,000 mechanical endurance cycles are typical for a fixed-mounted MCCB in a main or feeder role — not a switching-duty device, but adequate for infrequent operation.