What this 125 A MCCB delivers
The Siemens 3VA1132-5EE36-0AC0 is a SENTRON molded case circuit breaker (MCCB) rated for 125 A continuous current at 40 °C, with a TM240 thermal-magnetic overcurrent release. Its 187 kA interrupting capacity at 240 V AC means it can safely clear a bolted fault at that voltage without upstream coordination failure — critical for high-fault utility feeds or transformer secondaries. At 415 V it still holds 121 kA, and at 690 V it drops to 17 kA, so the SCCR rating on your panel label must match the voltage you actually run.
Thermal derating and real-world loading
The 125 A rating holds flat from 40 °C to 50 °C. Above that, it derates to 122 A at 55 °C, 120 A at 60 °C, 117 A at 65 °C, and 114 A at 70 °C. If your panel ambient runs above 50 °C, size the load current against the derated figure — not the nameplate 125 A.
Built-in auxiliary switching
The breaker ships with two HQ auxiliary switches (form C) for remote status indication — open/closed and tripped signals back to a PLC or annunciator panel. No undervoltage release, no shunt trip, no communication module on this variant; it is a straight line-protection device.