What the 1700 A AC-1 rating means for your resistive load
The LC1F1700R7 is a 3-pole TeSys F contactor rated for 1700 A conventional free-air thermal current (Ith) and 1700 A operational current in AC-1 utilisation category — that is, resistive loads such as large heating banks, furnace elements, or industrial ovens. AC-1 is the least stressful duty for a contactor because switching occurs at or near unity power factor with minimal arcing; the same contactor would carry a lower current in AC-3 motor duty. The 1700 A figure is the maximum continuous current the main poles can handle at 40 °C ambient without derating. Control is via a 440 V AC coil (40-400 Hz) drawing 2200 VA inrush and 36 VA holding. The coil holds in at 0.85 to 1.1 Uc and drops out between 0.3 and 0.5 Uc — a wide dropout margin that reduces the risk of chatter on a sagging line.
Lifecycle and sourcing reality — EOL phase, sourced to order
If you need a cross-reference, submit the LC1F1700R7 on an RFQ and we can research compatible alternatives from the same series.
Mounting and integration — plate-mount, bolted power connections
The contactor is designed for plate mounting — no DIN-rail clip. Dimensions are 438 mm wide, 332 mm high, and 238.6 mm deep, so it occupies a significant footprint in the enclosure. Power connections are bolted busbar (up to 100 x 5 mm cross-section) or cable lugs; control wiring uses screw-clamp terminals accepting 1 to 4 mm² flexible or solid conductors. Tightening torque is 58 N·m on the power circuit and 1.2 N·m on the control circuit.
Withstand and breaking capability — coordination data for the panel designer
Rated short-time withstand current (Icw) is 10,000 A for 10 seconds at 40 °C, tapering to 3,000 A for 10 minutes — useful for selective coordination studies. Rated breaking capacity is 2,550 A per IEC 60947-4-1. Associated fuse rating is 1,600 A gG at ≤ 440 V. Impulse withstand voltage is 8 kV, overvoltage category III. These figures let the panel builder size upstream protection and verify arc-flash incident energy limits.
Standards and approvals — global acceptance
The LC1F1700R7 is certified to IEC 60947-4-1, EN 60947-4-1, UL 60947-4-1, CSA C22.2 No 60947-4-1, and JIS C8201-4-1. Rated insulation voltage is 1,000 V per IEC/UL, 1,500 V per VDE 0110 Group C. Protective treatment is TH (tropicalized) for humid environments. Operating altitude is 3,000 m without derating.