The Siemens 3VA1220-5EF42-0JH0 is a SENTRON molded case circuit breaker (MCCB) sized for line protection in distribution panels. It carries a 200 A rated continuous current (Iu) and a TM240 thermal-magnetic release, so it handles feeder and large branch circuits where the load current stays under that threshold and the short-circuit duty is known. Breaking capacity is the headline here: 187 kA at 240 V, 121 kA at 415 V, 36 kA at 440 V, and 17 kA at 690 V. That 187 kA figure at 240 V means this breaker can interrupt a fault current up to that level without self-destructing — critical for high-capacity transformer secondaries or busway feeds where available fault current is high. The 121 kA at 415 V still covers most industrial 400 V distribution. Four poles, so it switches all three phases plus neutral (or a fourth phase in some configurations). The TM240 release is thermal-magnetic — thermal element for overload, magnetic for short-circuit. No electronic trip unit, no communication function, no ground-fault monitoring built in. This is a straightforward, field-proven design for standard line protection.
Thermal derating and panel fit
Rated continuous current holds at 200 A from 40 °C up to 50 °C. Above that it derates: 194 A at 55 °C, 188 A at 60 °C, 182 A at 65 °C, and 176 A at 70 °C. If the panel ambient runs hot — say next to a drive cabinet or a transformer — that 176 A at 70 °C is the number to use for sizing the downstream conductor and load. Dimensions: 70 mm deep, 140 mm wide, 158 mm high. That 140 mm width is a standard 4-pole MCCB footprint — it fits the same mounting base as other SENTRON 3VA frames. IP40 on the front means it's protected against tools and wires >1 mm, but not against water ingress; keep it inside a panel, not on the machine exterior. Comes with 2 auxiliary switches plus 1 trip alarm switch (HQ version). The shunt trip (STL) is integrated — order code 3VA9688-0BL32 for the auxiliary trip unit. No undervoltage release, no phase-failure detection, no N-conductor protection. If you need those, this isn't the variant; the 3VA family has other order codes for that.