The Siemens 3VA1120-4EE42-0AA0 is a 4-pole SENTRON molded case circuit breaker (MCCB) designed for line protection. It carries a continuous current rating of 20 A across the 40 °C to 55 °C band, derating to 19 A at 60 °C through 70 °C. The TM220 thermal-magnetic release handles overload and short-circuit protection in one package. Breaking capacity is 121 kA at 240 V, dropping to 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at both 500 V and 690 V — figures that define the available fault current the breaker can safely interrupt at each voltage level. Panel builders sizing for high-fault installations will use the 415 V or 480 V column for typical industrial distribution. Front face IP40. Insulation voltage rated 800 V. Maximum power loss 12 W.
Deployment Context
As a panel-mount MCCB, it integrates into switchboards and distribution panels via screw-clamp terminals. The 101.6 mm width (4 in) and 70 mm depth (2.76 in) determine the DIN-rail or mounting-plate footprint — critical when retrofitting into an existing panel layout or sizing a new enclosure. The TM220 release is a fixed thermal-magnetic trip, not electronic, so no auxiliary power or communication module is required for basic overcurrent protection. No undervoltage release, no ground-fault monitoring, no communication function — this is a straightforward line-protection breaker for standard distribution.