Siemens 3RV2021-0JA15 Motor Protection Circuit Breaker

Siemens 3RV2021-0JA15 is a Sirius motor protection circuit breaker (MPCB) in the S0 size that provides integrated overload protection, short‑circuit protection, and disconnect functionality for 690 V AC motor circuits. It uses an adjustable thermal overload release (A‑release) from 0.7 to 1.0 A and a fixed instantaneous release (N‑release) rated at 13 A, delivering Class 10 protection suitable for small to mid‑size motors. The unit includes a standard transverse auxiliary switch configuration of 1 NO + 1 NC for signaling, and it features screw terminals for robust field wiring. Designed for motor protection applications within Siemens' 3RV2 family, 3RV2021-0JA15 combines protection and signaling in a compact device suitable for control panels and motor starters in industrial automation. In practice, it protects motor windings from overload during startup and operation while providing a clear, mechanical disconnect and signaling path for control systems; its 690 V rating aligns with common industrial power distribution, and the built‑in auxiliary contact ensures status feedback to PLCs or controllers. The device's S0 frame and screw‑terminal construction support straightforward installation in standard control panels, making it a direct fit for Siemens Sirius MPCB configurations where space and integrated signaling are prioritized.