Breaking capacity and tripping characteristic
The 5SY4202-5: This means it trips at 2 to 3 times rated current, making it suitable for protecting semiconductor loads or long cable runs where standard curve C breakers would be too slow to react to short-circuit currents. The higher 35 kA figure applies when the breaker is used under industrial IEC 60947-2 rules, giving headroom for installations with high prospective fault current. At DC, the breaker is rated 15 kA at 60 V per IEC 60947-2.
DC suitability and operating conditions
Yes, the 5SY4202-5 is suitable for DC circuits. It carries a DC breaking capacity of 15 kA at a rated voltage of 60 V DC (maximum 72 V DC). The DC voltage rating is lower than the AC rating because DC arcs are harder to extinguish — the breaker's internal arc chamber is designed for this.
AC breaking capacity under UL 1077 is 5 kA.