Part identity and key ratings
The Siemens 3VA1220-5MH32-0DA0 is a SENTRON molded case circuit breaker (MCCB) in the starter protection version, rated for a continuous current Iu of 200 A across three poles. It carries a TM120M thermal-magnetic overcurrent release and an integrated undervoltage release (UVR) as the auxiliary trip design. Breaking capacity is 187 kA at 240 V, 121 kA at 415 V, 30 kA at 440 V, and 17 kA at 690 V — the 240 V and 415 V figures cover the most common low-voltage distribution and motor branch-circuit fault levels, while the 690 V rating confirms suitability for 690 V line-to-line systems where available fault current stays under 17 kA. Rated insulation voltage Ui is 800 V, matching the insulation coordination expected for 690 V nominal systems with overvoltage category III.
Thermal performance and derating
The breaker holds its full 200 A rating from 40 °C through 50 °C ambient. Derating begins at 55 °C (192 A), dropping to 188 A at 60 °C, 184 A at 65 °C, and 180 A at 70 °C — the 70 °C figure matches the maximum operating ambient, so the derating curve covers the full temperature range a panel might see near a heat source or in a sealed enclosure. Storage temperature range is -40 °C to 80 °C, which exceeds the operating range — handling and shipping, not running, are what those limits govern.
Motor duty and endurance
Operating power at AC-3 duty (motor switching) at 400 V is 75 W — this is the power dissipated by the breaker under load, relevant for enclosure thermal calculations. Mechanical endurance is rated at 15 000 operations, typical for a fixed-mounted MCCB in a distribution panel or motor control center.
Physical footprint and mounting
Dimensions are 105 mm width, 158 mm height, and 70 mm depth. The 105 mm width is the standard 3-pole MCCB footprint for this SENTRON frame size, fitting directly into the panel cutout or mounting base without adapters. Front protection is IP40, meaning tools and fingers are kept out, but the breaker is intended for indoor panel installation — not washdown or outdoor exposure.
Lifecycle and sourcing
The integrated auxiliary trip is specified as order code 3VA9608-0BB25 — that sub-assembly is the undervoltage release module that mates with this breaker. No auxiliary contact version is included as standard.