The Siemens 3VM1150-4GD42-0AA0 is a SENTRON molded case circuit breaker (MCCB) built for line protection in industrial power distribution. Four-pole construction with a TM210 thermal-magnetic overcurrent release — the 210 designator means the fixed thermal pickup is 210 A, but the breaker itself is rated for a continuous 50 A at 40 °C. That 50 A holds steady up to 50 °C; at 55 °C it derates to 49 A, and at 70 °C it's 45 A (–). The 121 kA interrupting rating at 240 V AC means it can safely clear a fault up to that level without upstream damage — useful for high-fault utility feeds in cement plant MCC rooms where the available fault current is no joke.
Breaking capacity across voltages
This MCCB carries a 76 kA interrupting rating at 415 V, 53 kA at 440 V, and 12 kA at 500 V (–). That's the short-circuit current it can interrupt at each voltage level — critical for selectivity coordination downstream of a transformer. The insulation voltage is rated at 800 V.
Mounting and environment
Front-face protection is IP40 — sealed against tools and solid objects larger than 1 mm, but not dust-tight. In a cement plant control room that sees clinker dust infiltration, you'll want it inside a gasketed enclosure, not exposed open-air. Operating temperature range is -25 °C to 70 °C; storage from -40 °C to 80 °C. The 70 mm depth and 101.6 mm width fit standard panel-mount cutouts for 4-pole MCCBs in this class.
Key specs at a glance
Minimum operating current is 1 A. Maximum power loss is 15 W. No undervoltage release, no voltage trip, no communication function, no ground-fault monitoring — this is a straight thermal-magnetic breaker for basic overcurrent and short-circuit protection. The N-conductor protection is rated at 100%.