Siemens 5SY8604-7 — 4 A C-Curve MCB, 4-Pole, 50 kA
The Siemens 5SY8604-7 is a SENTRON miniature circuit breaker rated 4 A with a C tripping characteristic, 4 poles (3P+N), and a 50 kA breaking capacity at 400 V AC per IEC 60947-2. This is a current-production part in the 5SY8 design series, suitable for panel building and industrial distribution.
The 4 A rated current with C-curve means it trips at 5 to 10 times rated current (20–40 A magnetic release), covering motor-start and transformer inrush without nuisance trips. The DC breaking capacity is 15 kA per IEC 60947-2, and under UL 1077 / CSA C22.2 No.235 it carries a 5 kA interrupting rating. The 4-pole (3P+N) configuration protects all three phases and switches the neutral, common in 3-phase 4-wire systems (TN-C-S, TN-S) where the neutral must be disconnected for isolation.
Mounting and wiring — fits standard DIN rail
Snap-on mounting to DIN rail EN 60715, 72 mm wide (4 width units of 18 mm). The 76 mm depth (70 mm installation depth) fits standard enclosures with 80 mm deep gland plates. Conductor cross-section accepts 0.75 to 35 mm² solid or stranded; tightening torque 2.5 to 3.5 N·m with screw terminals. Combined top and bottom terminals simplify daisy-chaining busbars. Ambient temperature range -25 to +55 °C; storage -40 to +75 °C. Mounting position any, which helps in tight enclosures.
Rated per IEC 60947-2 (50 kA at 400 V AC, 15 kA DC) and UL 1077 / CSA C22.2 No.235 (5 kA). Overvoltage category III. Halogen-free and silicon-free construction. Sealable — allows lockout/tagout for maintenance isolation. Touch protection integrated.