SENTRON 3VA1120-6EF36-0AC0 — line-protection MCCB, 20 A frame
The Siemens SENTRON 3VA1120-6EF36-0AC0 is a 3-pole molded case circuit breaker (MCCB) designed for line protection, carrying a 20 A rating at 40 °C ambient and a TM240 thermal-magnetic overcurrent release. It breaks up to 220 kA at 240 VAC, 154 kA at 415 VAC, 121 kA at 440 VAC, and 17 kA at both 500 VAC and 690 VAC — so the interrupting capacity drops sharply above 440 V; at 690 V the 17 kA figure governs the fault-current limit for that installation. The 800 V rated insulation voltage (Ui) means the breaker is rated for 690 V line-to-line systems without derating the internal isolation. This is a current-production part (lifecycle stage: current), so it moves through the standard Siemens distribution channel. No communication module, no ground-fault monitoring, no undervoltage release on this variant — it is a straight thermal-magnetic line-protection breaker with two HQ auxiliary switches built in.
Mounting and panel fit
The breaker measures 76.2 mm wide, 130 mm tall, and 70 mm deep — a standard 3-pole MCCB footprint that fits most DIN-rail or panel-mount enclosures. The 70 mm depth means it clears a typical 100 mm deep gland plate with room for wiring. Maximum power loss is 12 W, so in a sealed enclosure with multiple breakers side by side, account for that heat when sizing the cabinet ventilation.
Thermal derating and operating range
The breaker holds its 20 A rating from 40 °C through 55 °C; at 60 °C and 65 °C it derates to 19 A, and at 70 °C it stays at 19 A. Operating ambient range is -25 °C to +70 °C, storage from -40 °C to +80 °C. The trip indicator is absent on this variant — you will not get a visual flag; the auxiliary switches are the only remote status.