The Schneider TeSys K LP2K12004MD3 is a 4-pole changeover contactor — a reversing contactor pair mechanically interlocked so both main contacts cannot close simultaneously. It ships preassembled with the reversing power busbar, which saves panel-build time wiring the interlock and power loop between the two contactors. The control circuit is 220 V DC, with a built-in bidirectional peak-limiting diode suppressor across the coil. That suppressor handles the inductive kick from the DC coil, so you do not need an external flyback diode on the control wiring. Rated in AC-1 utilisation category for resistive loads, the contactor carries 20 A continuously (Ith) with a power-circuit impedance of 3 mOhm at 50 Hz. Heat dissipation is 3 W at 20 °C coil temperature.
The AC-1 rating (20 A at ≤440 V) governs resistive loads — heaters, incandescent lamps, resistive banks. For motor or inductive loads you would need the AC-3 rating, which this listing does not carry; this part is selected for switching resistive circuits where the inrush is low and the breaking current is close to the continuous current. Rated breaking capacity is 110 A at 440 V, 80 A at 500 V, and 70 A at 660–690 V per IEC 60947. Mechanical durability is 5 million cycles; electrical durability is 300,000 cycles at 20 A AC-1. Mounts on rail or plate. Screw-clamp terminals accept up to 4 mm² solid or 2.5 mm² flexible with ferrule.
Changeover contactors of this class are used in control panels for reversing motor starters (forward/reverse), dual-speed motor switching, or source transfer between two supplies. The mechanical interlock prevents a phase-to-phase short if both contactors close simultaneously.
Approvals include IEC 60947, VDE 0660, NF C 63-110, BS 5424, UL 508, CSA C22.2 No 14, and UL 94 V1 flame retardance. The part also carries B10d reliability data per EN/ISO 13849-1 for safety-related control systems.