What the ratings mean for fit
The Siemens 3VA2340-5JQ42-0AH0 is a SENTRON molded case circuit breaker (MCCB) rated 400 A continuous at 40 °C, 4-pole, designed for line protection in distribution panels. The 187 kA interrupting capacity at 240 V AC means it can safely clear a fault up to that level without upstream cascading — critical for high-fault installations like transformer secondaries or large motor control centers. At 415 V and 440 V the SCCR holds at 121 kA, dropping to 75.6 kA at 500 V and 7.5 kA at 690 V; the 690 V figure is the practical ceiling for this frame. Operating temperature range is -25 °C to 70 °C; the current rating derates above 50 °C — 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, 300 A at 70 °C. Storage range is -40 °C to 80 °C. The breaker includes a communication function (likely PROFIBUS or PROFINET via an optional module) and comes with 2 auxiliary switches plus 1 trip alarm switch (HQ type) factory-fitted.
Sourcing and lifecycle
The basic switch variant is 3VA2340-5JQ42-0AA0 (without the auxiliary switch package). If your BOM calls for the -0AH0 suffix, the auxiliary switches and trip alarm are integrated — no separate ordering. No undervoltage release or other auxiliary release is fitted on this variant.
Comparison with 3VA1110-5EF32-0AM0
The closest functional peer in the SENTRON family is the 3VA1110-5EF32-0AM0. The 3VA1110 is a smaller-frame MCCB — typically 100 A class, lower interrupting capacity, and fewer poles. The 3VA2340-5JQ42-0AH0 is a full 400 A frame with 4 poles and 187 kA SCCR; it will not drop into a panel wired for the 3VA1110 without busbar and lug rework. If your panel was specified around the 3VA1110, this 3VA2340 is not a direct mechanical swap — the mounting footprint and lug centers differ.