The LC1F185FE7: The headline rating is 275 A at ≤ 440 V AC-3 — that is the motor-switching current, not the resistive load rating. AC-3 duty covers starting and running of squirrel-cage motors, so the 275 A figure governs the contactor's ability to handle inrush and break the motor circuit under load. For resistive loads (AC-1), the thermal current Ith is 275 A at 50 Hz with an average impedance of 0.33 mOhm per pole. The motor power table is the practical selection tool: 90 kW at 380-400 V, 100 kW at 415 V, 100 kW at 440 V, 110 kW at 500 V, and 110 kW at 660-690 V — all AC-3. At 220-230 V AC-3 it drops to 55 kW. For AC-4 reversing or inching duty at 400 V, the rating is 33 kW. The 115 V AC control coil (40-400 Hz) pulls 1070 VA inrush at cos φ 0.9; hold-in dissipation runs 8-9.8 W total. The coil pick-up range is 0.85-1.1 Uc, drop-out between 0.2-0.55 Uc — important for brownout ride-through assessment.
The contactor is designed and tested to EN 60947-1, IEC 60947-1, EN 60947-4-1, IEC 60947-4-1, and JIS C8201-4-1. Rated insulation voltage (Ui) is 1000 V per IEC 60947-4-1, 1500 V per VDE 0110 Group C. Overvoltage category III. The rated breaking capacity is 1480 A per IEC 60947-4-1. Protective treatment is TH (tropicalized). Front face with shrouds achieves IP2X per IEC 60529 and VDE 0106. Associated fuse protection: 200 A aM or 315 A gG at ≤ 440 V.
Mechanical & Mounting
Mounting is plate-mount (not DIN rail). Dimensions: 174 mm height, 168.5 mm width, 181 mm depth. Power circuit connections accept bar (25 x 3 mm busbar), ring terminals, or bolted connection for 1 x 150 mm² cable. Control circuit uses screw clamp terminals accepting 1-4 mm² flexible or solid (1 or 2 cables). Tightening torque: 18 N.m on power circuit, 1.2 N.m on control. Mechanical durability is 10 million cycles; maximum operating rate is 2400 cycles per hour at 55 °C. Operating time: 35 ms closing, 130 ms opening at rated control voltage.
Deployment Context
The plate-mount form factor and 275 A AC-3 rating place it in the heavy-duty motor starter class — typically feeding conveyors, pumps, compressors, or large fans on 400-690 V three-phase supplies. The IP2X front face with shrouds provides basic finger protection inside an enclosed panel. The 115 V AC coil is standard for North American and some Asian control voltage schemes.