What it guards and how it fits
The RM4JA31Q: The measurement range spans four overlapping bands: 0.3...30 mA, 10...100 mA, and 100...1000 mA, selectable for both AC and DC. So the same relay can sit on a 4-20 mA transducer loop or a direct motor phase current shunt — no separate module needed. The adjustable time delay (0.05...30 s) lets you ride through inrush or transient spikes without nuisance trips — set it short for fast fault detection on a heater, longer for a motor start profile.
Panel fit and wiring
At 23 mm wide and 80 mm deep, it takes up one standard DIN-rail module — no more. The screw terminals accept two 1.5 mm² flexible wires with ferrules or two 2.5 mm² without, so daisy-chaining the supply and output commons is straightforward. IP20 at the terminals, IP50 on the casing — it lives inside a panel, not on the machine face. Pollution degree 3 per IEC 60664-1 means it handles conductive dust and condensation typical of industrial enclosures without creepage failures.