What the 1700 A AC-1 rating means for fit
The Schneider Electric LC1F1700L7 is a 3-pole contactor from the TeSys F range, rated for 1700 A conventional free-air thermal current (Ith) and 1700 A operational current in AC-1 utilisation category — that is, purely resistive loads such as large heating banks, furnace elements, or power-factor correction capacitor banks. The AC-1 rating is the headline figure: at 40 °C ambient, it carries 1700 A continuously without derating. For motor or inductive loads (AC-3/AC-4), this contactor is not the correct selection; the AC-1 duty class governs its application. The control circuit is 208 V AC at 40–400 Hz, with a hold-in consumption of 36 VA and an inrush of 2200 VA.
This contactor carries approvals 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. The rated insulation voltage (Ui) is 1000 V per IEC/UL, and 1500 V per VDE 0110 group C. Impulse withstand voltage (Uimp) is 8 kV. Overvoltage category III. Protective treatment is TH (tropicalised). Compliance documentation — including RoHS, REACH, and the relevant IEC/UL test reports — is available from the manufacturer's archive for this series.
The LC1F1700L7 is a plate-mount contactor — it does not snap onto a DIN rail. The dimensions are 438 mm wide, 332 mm high, and 238.6 mm deep. Power circuit connections are via bolted busbars (bar, 3 cables, busbar cross-section 100 x 5 mm). Control circuit wiring uses screw-clamp terminals accepting 1 to 4 mm² flexible or solid cable (with or without ferrule). Tightening torque for the power circuit is 58 N.m; control circuit is 1.2 N.m. Heat dissipation is 36 W at rated current. These figures matter for panel layout: the busbar connection requires planning for bending radius and access, and the 36 W dissipation must be accounted for in enclosure thermal calculations.
Short-time withstand and coordination
For selective coordination with upstream protection, the LC1F1700L7 offers rated short-time withstand current (Icw) of 10,000 A for 10 seconds, 7500 A for 30 seconds, 5500 A for 1 minute, 4200 A for 3 minutes, and 3000 A for 10 minutes — all at 40 °C. The associated fuse rating is 1600 A gG at ≤ 440 V. Rated breaking capacity is 2550 A per IEC 60947-4-1. These values let a site electrical engineer size the upstream breaker or fuse to achieve Type 2 coordination without nuisance tripping during a downstream fault.