Motor Integrated Protection Settings

Overload, locked-rotor, negative-sequence unbalance and ground-fault pickup for a three-phase motor (IEC 60947-4-1 / IEC 60255).

Inputs

Full-load current Iₑ A

Overload factor (× Iₑ) —

Inverse-time class (10/20/30) s

Locked-rotor multiple (× Iₑ) —

Trip-time current multiple (× Iₑ) —

Phase A current Iₐ A

Phase A angle °

Phase B current I_b A

Phase B angle °

Phase C current I_c A

Phase C angle °

Unbalance pickup (% of Iₑ) %

Residual (ground) current I_res A

Ground-fault pickup A

Results

Note — Overload uses an IEC 60947-4-1 inverse curve (no trip at ≤1.05×Iₑ). Negative-sequence current drives unbalance protection; ground pickup uses the residual/restricted-earth scheme. These are first-cut settings — confirm against the relay manual and a protection study.