Switch Disconnector for Load Isolation — 63 A, No Overload Trip
The Siemens 3VA1163-1AA32-0DH0 is a 3-pole SENTRON switch disconnector in an MCCB-style housing, rated for 63 A continuous across the full operating temperature range from 40 °C to 70 °C — no derating needed up to the top of the thermal envelope. It provides manual load isolation and safe disconnection under load, but carries no overload or short-circuit protection elements internally; it is a disconnect-only device, not a circuit breaker. The built-in undervoltage release (UVR) rated 208-230 V AC 50/60 Hz will trip the switch if control voltage drops, adding a layer of remote or protective shutdown for furnace or motor feeder circuits.
Flat Thermal Curve — No Derating Between 40 °C and 70 °C
That means a panel designer can size the busbar and connections for a constant 63 A without calculating temperature correction factors for the disconnector itself. The maximum power loss is 38 W at rated current, so the heat dissipated into the enclosure is predictable and moderate for a 63 A device. Mechanical service life is 15,000 operating cycles typical — adequate for infrequent manual switching or maintenance isolation, not for daily cycling under load.
Panel Integration — Busbar Connection, Front Terminals
The main current circuit connects via busbar connection at front terminals — no screw-clamp lugs for cable tails, so plan for busbar taps or adapter kits. The 76.2 mm width (3-inch footprint) and 70 mm depth fit standard MCCB panel cutouts and DIN-rail adapters. The undervoltage release coil is wired separately; verify control voltage matches the 208-230 V AC 50/60 Hz rating before energizing. The auxiliary switch block provides 3 CO contacts total (2 aux + 1 trip alarm), enough to report position and fault status to a control system.