MCCB for motor-starting duty
The Siemens 3VA1220-5MH32-0AH0 is a SENTRON molded case circuit breaker (MCCB) configured as a starter protector — meaning it combines short-circuit and overload protection in one device sized for motor branch circuits. Rated continuous current Iu is 200 A, and the TM120M thermal-magnetic release provides the inverse-time curve needed to handle inrush without nuisance tripping. The 187 kA interrupting rating at 240 V gives substantial fault-current headroom for low-voltage distribution; at 415 V it still clears 121 kA, and at 690 V it holds 17 kA. That spread covers most industrial panel secondary voltages.
Thermal derating and panel fit
The 200 A rating holds flat from 40 °C through 50 °C ambient. Above that it derates: 192 A at 55 °C, 188 A at 60 °C, 184 A at 65 °C, and 180 A at 70 °C. If the panel ambient runs hot — say a non-ventilated enclosure near a furnace line — size the load to the 70 °C figure, not the nameplate. The 3-pole frame measures 105 mm wide by 158 mm high by 70 mm deep, which fits standard Siemens 3VA panel cutouts and bus-bar spacing. IP40 on the front means it's protected against tools and solid objects larger than 1 mm; the interior of the enclosure handles the rest.
Voltage and application limits
Rated insulation voltage Ui is 800 V, and the maximum DC operational voltage is 500 V — so it can serve DC bus or battery circuits up to that level, though the interrupting ratings listed are AC values. The operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. No undervoltage release, no ground-fault monitoring, no phase-failure detection, and no communication function are built in — this is a straightforward thermal-magnetic protector with auxiliary signaling only.