The Siemens 3VA1163-4EF36-0CA0 is a SENTRON molded case circuit breaker (MCCB) rated for line-protection duty, carrying a continuous current of 63 A at 40 °C and a short-circuit breaking capacity of 121 kA at 240 V AC. The 3-pole frame includes an integral undervoltage release (UVR) that trips the breaker when control voltage drops below the dropout threshold — a standard requirement for emergency-stop circuits and undervoltage protection schemes. The insulation voltage is rated at 800 V, so it can be applied in 480Y/277 V and 600 V delta systems without derating the dielectric withstand.
Breaking capacity across system voltages
The interrupting rating varies with system voltage: 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at both 500 V and 690 V. This means the same breaker can be used in 400 V-class panels with high available fault current, but at 690 V the SCCR drops to 11.9 kA — verify that the upstream transformer or generator can deliver less than that figure, or step up to a higher-rated frame. The 121 kA at 240 V covers most 208Y/120 V and 240 V delta service-entrance applications without a current-limiting fuse ahead of it.
Thermal derating and power loss
The 63 A rating holds flat from 40 °C to 50 °C, then derates to 62 A at 55 °C, 61 A at 60 °C, 60 A at 65 °C, and 58 A at 70 °C. In a sealed, non-ventilated enclosure with multiple breakers ganged, the ambient temperature inside the panel can easily reach 55–60 °C; the derating curve lets you size the breaker for actual operating conditions rather than the nameplate. Maximum power loss is 19.8 W per pole — relevant for thermal budgeting in compact sub-distribution boards where heat buildup affects adjacent devices.
Lifecycle and sourcing posture
The lifecycle stage is listed as current, meaning Siemens continues to manufacture and support this order code without an announced phase-out. The part is sourced to order against an RFQ through independent distribution; availability and current pricing are confirmed at quote time.
Physical integration and approvals
Dimensions are 130 mm height, 76.2 mm width, 70 mm depth — a standard 3-pole MCCB footprint that fits most Siemens SENTRON panelboards and third-party enclosures using the same bolt-on or plug-in base. The operating temperature range is -25 °C to 70 °C, and storage range is -40 °C to 80 °C, so it can be warehoused in unconditioned spaces and installed in outdoor enclosures with heaters. The undervoltage release (UVR) is factory-fitted; no field kit required.