Siemens 5SY4640-5 — 40 A, 4-pole MCB with Characteristic A
This characteristic is designed for semiconductor protection or long cable runs where inrush is minimal — it trips between 2 and 3 times rated current, faster than B or C curves, so it suits sensitive loads that cannot tolerate a prolonged overcurrent. Rated at 400 V AC and 72 V DC maximum, this 4-pole unit occupies 4 width units (72 mm) on a DIN rail. The quick-assembly mounting system and any-position orientation simplify panel integration.
Integration and Sourcing
The sealable design allows lockout/tagout for maintenance isolation. Ambient temperature range of -40 to +70 °C covers most industrial environments; humidity limits are 95% at 55 °C, derating to 55% at 70 °C and 35% at 75 °C.