What this MCCB is and where it fits
The Siemens SENTRON 3VA1150-5MH36-0AA0 is a 3-pole molded case circuit breaker (MCCB) rated for 50 A continuous current with a TM120M thermal-magnetic overcurrent release. It carries 187 kA interrupting capacity at 240 V and derates through 121 kA at 415 V, 75.6 kA at 440 V, and 7.5 kA at both 500 V and 690 V — so the same breaker covers low-voltage distribution and motor branch circuits across a wide voltage range without swapping frame sizes. The TM120M release means the thermal element tracks the load current continuously; the magnetic instantaneous pickup is fixed at the TM120M calibration, which suits motor-starting inrush and feeder protection where you need coordination with downstream devices. This is the starter-protection version of the 3VA platform — the product version field confirms it — so it is configured for motor branch-circuit duty rather than straight distribution. The 50 A rating holds flat from 40 °C through 50 °C, then derates to 49 A at 55 °C, 48 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C. In a warm panel (55 °C ambient) you lose only 1 A; at 70 °C you still have 45 A of headroom. The rated insulation voltage is 800 V, so it can be applied in 480/277 V and 600 V systems without a voltage derating concern.
Physical fit and panel integration
Dimensions are 130 mm high, 76.2 mm wide, 70 mm deep. The 70 mm depth clears a standard enclosure with room for wiring and a bus stack behind it. No trip indicator, no undervoltage release, no communication function, no phase failure detection, and no ground-fault monitoring on this variant. If you need a shunt trip, UVR, or electronic trip unit (ETU), this is the wrong order code — those are separate 3VA variants. The TM120M is a pure thermal-magnetic release; no auxiliary power required, no settings to lose on a power cycle.
Lifecycle and sourcing posture
Lifecycle stage is marked current — this is an active, in-production catalog number. No last-time-buy notice, no phase-out date.
Thermal performance and power loss
Maximum power loss is 14.6 W at rated current. Storage temperature range is -40 °C to 80 °C; operating ambient is -25 °C to 70 °C.