It's the electronic alternative to a bimetal relay when you need tighter repeatability and a wider ambient compensation range.
The straight-through transformer design means the power conductors pass through the relay body without looping; no separate current transformers to mount. Front protection is IP20 — safe against finger contact, but the relay needs to live inside an enclosure rated for the environment. The auxiliary contact ratings span 24 V / 2 A up to 230 V / 3 A — enough to switch a PLC input or a small contactor coil directly. ATEX approval PTB 06 ATEX 3001 Ex II (2) GD means it can be used in gas/dust hazardous zones as an associated apparatus — the relay itself sits in the safe area but protects motors in Zone 1/2 or 21/22. That's a differentiator vs. standard thermal overloads.
Integration notes
Depth 109 mm, height 92 mm. Solid conductor capacity 0.5–4 mm² single or 2× 0.5–2.5 mm². Side clearance 6 mm to adjacent devices; no extra spacing needed upwards/forwards/backwards (0 mm). That keeps the panel layout tight — you can stack it directly next to the contactor. Operating temperature -25 to +60 °C, storage/transport -40 to +80 °C. Shock rated 15g / 11 ms — survives shipping and moderate machine vibration. Relative humidity tolerance 100% (condensing), so condensation in an unheated cabinet won't cause false trips. EMC immunity: 2 kV burst on power ports (severity 3 per IEC 61000-4-4), 1 kV on signal ports, surge 6 kV. That's standard for industrial control panels — no extra filtering needed for most installations.