Line protection MCCB with ETU850 — 63 A, 3-pole
The Siemens SENTRON 3VA2063-5KP32-0CL0 is a 3-pole molded case circuit breaker (MCCB) rated for 63 A continuous current, configured for line protection duty. It carries an ETU850 electronic trip unit with communication and measurement functions — meaning it can report current draw and trip events back to a controller, not just interrupt fault current silently. Interrupting capacity is 187 kA at 240 V, 121 kA at 415 V and 440 V, 79 kA at 500 V, and 3.4 kA at 690 V. That 187 kA figure at 240 V is the headline — this breaker handles very high available fault current on low-voltage distribution, typical for large transformer secondaries or generator paralleling gear. Thermal derating is minimal up to 50 °C (full 63 A), then drops to 60.6 A at 55 °C, 58.3 A at 60 °C, 55.9 A at 65 °C, and 53.6 A at 70 °C. In a warm enclosure — say a non-ventilated panel near a furnace line — expect to downrate to about 55 A if ambient hits 65 °C.
Auxiliary releases and switch complement
This variant includes an undervoltage release (UVR) — the basic switch supplied is 3VA2063-5KP32-0AA0, and the integrated auxiliary trip is 3VA9608-0BB24. The auxiliary contact block provides 2 auxiliary switches plus 1 trip alarm switch and 1 electrical alarm switch (HQ type). That gives four signal paths for the PLC: breaker open/closed, trip event, and a separate electrical alarm. Rated insulation voltage is 800 V, and maximum power loss is 7.9 W — modest for a 63 A frame, so ventilation requirements are light. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C.
Lifecycle and sourcing
Mechanical endurance is rated at 20,000 operations — typical for a 63 A MCCB frame used in distribution rather than frequent motor switching. For higher-cycle applications (conveyor start/stop), consider a contactor downstream.
Panel fit and dimensions
Dimensions are 181 mm height, 105 mm width, 86 mm depth. The 105 mm width is the standard 3-pole MCCB footprint for this frame size — it occupies three 35 mm DIN module positions if mounted on a DIN rail, or bolts directly to a mounting plate. Depth of 86 mm leaves clearance for rear-connected busbars or a cable duct behind the breaker.