Siemens 3VA1120-6EF36-0HC0 — SENTRON MCCB for Line Protection
The Siemens 3VA1120-6EF36-0HC0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection in distribution panels. It carries a 20 A rated current across a wide ambient temperature range — full rating holds from 40 °C up to 55 °C, then derates to 19 A at 60 °C through 70 °C, which is typical for a panel with limited airflow. The 3-pole construction and 800 V rated insulation voltage suit it for 400/480 VAC three-phase systems common in industrial switchgear. Breaking capacity is the headline: 220 kA at 240 VAC, 154 kA at 415 VAC, 121 kA at 440 VAC, and still 17 kA at 500 V and 690 VAC. That 220 kA figure at 240 V means it can interrupt very high fault currents typical on the secondary side of large distribution transformers, giving the panel designer selectivity headroom without cascading upstream. At 690 V the 17 kA rating still covers most industrial motor-circuit fault levels.
Built-in Auxiliaries and Release Options
This variant ships with a factory-installed shunt trip (STL) release and two HQ auxiliary switches, so it arrives ready for remote tripping and status feedback without adding separate accessory kits. The shunt trip lets a control system or emergency-stop circuit open the breaker remotely — useful on a line where a safety PLC or fire-alarm panel needs to kill power. The two auxiliary switches provide normally-open/normally-closed contacts for indicating the breaker position back to a PLC or status lamp. The supplied basic switch is order code 3VA11206EF360AA0, which is the core MCCB without the auxiliaries — this 3VA1120-6EF36-0HC0 is the fully assembled variant with the shunt trip and auxiliary switches pre-mounted and tested. No communication function is built in (no PROFIBUS or Modbus), so status feedback is limited to the hardwired auxiliary contacts.
Physical Fit and Panel Integration
Dimensions: 130 mm height, 76.2 mm width (3 inches), 70 mm depth. The 76.2 mm width is standard for a 3-pole MCCB in the SENTRON 3VA1 frame — it occupies three 25.4 mm pole spaces on a DIN rail or panel-mount footprint. Depth of 70 mm means it clears a standard 100 mm deep enclosure with room for rear-connected busbars or cabling. Maximum power loss is 12 W, which is manageable for thermal budgeting inside a sealed panel; no forced ventilation required at the 20 A load point.