Siemens 3VA1112-5EF32-0AG0 — SENTRON MCCB, 125 A, Line Protection
The Siemens 3VA1112-5EF32-0AG0 is a SENTRON molded case circuit breaker (MCCB) rated for 125 A continuous current (Iu) across a 3-pole configuration, built for line protection duty. It carries a TM240 thermal-magnetic overcurrent release — the thermal element handles overloads, the magnetic element clears short circuits. No undervoltage release, no ground-fault monitoring, no communication module on this variant; it's a straight thermal-magnetic breaker for standard distribution panels.
Breaking capacity — what the voltage-specific ratings mean for fault clearing
Breaking capacity is stated per voltage level: 187 kA at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at 690 V. These are the maximum fault currents the breaker can safely interrupt at those system voltages. For a 415 V industrial panel fed from a transformer with a 100 kA prospective fault current, this breaker clears it. At 690 V the margin is tighter — 17 kA limits it to lower-fault installations.
Thermal derating — continuous current across ambient temperature
Rated continuous current holds at 125 A from 40 °C through 50 °C. Above that it derates: 120 A at 55 °C, 117.5 A at 60 °C, 115 A at 65 °C, and 112.5 A at 70 °C. If the panel ambient runs hot — say 55 °C inside the enclosure — you lose 5 A of headroom. Plan the load at the actual ambient, not the nameplate.
Physical fit and panel integration
Footprint: 76.2 mm wide, 130 mm tall, 70 mm deep. That 70 mm depth is the dimension to check against the gland plate or enclosure back wall — it's not a shallow unit. Front protection is IP40, so it's fine inside a clean panel but not for washdown areas. Auxiliary contact set includes one auxiliary switch plus one trip alarm switch (HP type). The trip indicator flag is present — visible through the front cover, useful for troubleshooting without opening the panel door.