Siemens 3RR2242-2FW30 Current Monitoring Relay

Siemens 3RR2242-2FW30 is a SIRIUS current monitoring relay that mounts on a 3RT2 contactor (size S0) to provide digitally adjustable monitoring of current and phase status for multi‑phase loads. It supports 4–40 A apparent/current monitoring over a 20–400 Hz supply window and runs from 24–240 V AC/DC, delivering one change‑over contact plus one semiconductor output for alarm and warning; separate settings for warning and alarm thresholds, with optional fault buffering, let you tailor protection to your application. The unit detects current overshoot/undershoot, phase failure, cable break, and phase sequence faults, with ON‑delay 0–99 s, spurious peak suppression 0–30 s, and a fault pause of 0–300 min to manage nuisance trips. Electrical ratings include insulation up to 690 V and surge resistance up to 6 kV, with IP20 protection and rugged DIN‑rail mounting suitable for control cabinets; mechanical specs list shock resistance around 15 g/11 ms and vibration resistance around 10 g. As part of the 3RR2 family, it can plug into Siemens SIRIUS 3RT2 assemblies or operate as a standalone monitoring device for the entire driven process, offering precise current monitoring and reliable fault signaling through its distinct alarm and warning outputs.