Siemens 5SJ6432-6 SENTRON MCB — 4-pole B-curve at 32 A
The Siemens 5SJ6432-6 is a 4-pole SENTRON 5SJ6 miniature circuit breaker rated 32 A at 400 V AC with a B-curve tripping characteristic and 6 kA breaking capacity per EN 60898 and IEC 60947-2. Four poles let it switch three-phase plus neutral in a single module, saving a width unit compared to separate single-pole breakers.
The insulation voltage is rated 440 V AC, giving headroom on 400 V nominal systems. Energy limiting class 3 means it restricts let-through energy well, protecting downstream wiring and loads during a fault. Rated for 50 Hz AC/DC operation, with a maximum DC voltage of 60 V — usable on DC control circuits up to that level, though the DC breaking capacity is not separately stated. The B-curve is not ideal for motor starting or transformer inrush; that calls for a C or D curve. For a 32 A resistive load on a 400 V three-phase supply, this is the right call.
Temperature range and environmental fit
Operating ambient is derated from the -20 °C to +45 °C typical for the 5SJ6 family, with periodic exposure to +55 °C and 95% humidity. Vibration resistance tested to 50 m/s² at 25 to 150 Hz and 60 m/s² at 10 to 150 Hz per IEC 60068-2-6, so it holds up on machinery or in mobile equipment.
Snap-on mounting to DIN rail EN 60715, any position. The 4-pole design occupies 4 width units (about 72 mm at 18 mm per pole). Touch protection is built in — finger-safe terminals with connected conductors. Sealable with a lead seal for tamper-proof installations.