The DPER350 is a differential thermal overload relay from the Easy TeSys range, designed for motor protection in industrial control panels. It protects motors against overload, phase failure, and phase unbalance by monitoring current and tripping when the thermal load exceeds the set threshold. The thermal protection adjustment range spans 37 to 50 A, and the relay is rated as Class 10 per IEC 60947-4-1, meaning it will trip within 10 seconds at 7.2× the set current — fast enough to protect standard induction motors during a stall or locked-rotor condition. Phase failure sensitivity is built in: the relay trips when current on two phases reaches 130% of Ir while the third phase drops to zero, covering the most common motor failure mode in three-phase systems.
The IP20 finger-safe enclosure (IEC 60529) suits panel-mount applications where the relay is behind a cabinet door. Power circuit connections accept 2.5–25 mm² flexible or solid wire; control circuit terminals take 1–2.5 mm². Tightening torque is 44.3 lbf·in (5 N·m) for the power side, 15.05 lbf·in (1.7 N·m) for the control side.
Approvals include UL 60947-4-1, CSA C22.2 No 60947-4-1, and EN/IEC 60947-4-1, covering installations in North America and Europe. The relay also meets EN 50495 for safety-related applications in potentially explosive atmospheres.