The LADN40G is a TeSys Deca auxiliary contact block from Schneider Electric, configured with 4 normally open (4NO) instantaneous contacts. It mounts on the front of a contactor or starter and provides additional control-circuit switching for signaling, interlocking, or PLC inputs. Rated at 10 A conventional free air thermal current (Ith) at 60 °C, it handles 6 A at 120 V AC-15 (solenoid/contactor loads) and 0.55 A at 125 V DC-13. The insulation voltage (Ui) is 690 V, compliant with IEC 60947-5-1 and UL 60947-5-1.
The 10 A thermal current rating (Ith) at 60 °C is the continuous carry capacity in free air — it governs the maximum load on the block itself, not the switched load. The AC-15 and DC-13 ratings are the ones that matter for actual switching: 6 A at 120 V AC covers most pilot-duty solenoids and contactor coils; 0.55 A at 125 V DC covers small DC relays and indicators. Minimum switching capability is 5 mA at 17 V, so the block can reliably switch low-energy PLC inputs or dry-contact signals without needing a separate interface relay. The making capacity — 140 A AC and 250 A DC — tells you the block can handle the inrush of a large contactor coil without welding its own contacts. The short-time ratings (100 A for 1 s, 120 A for 500 ms, 140 A for 100 ms) cover fault-level current before the upstream fuse clears. Screw clamp terminals accept 1 to 4 mm² rigid or flexible wire (single or dual conductors with ferrules). Tightening torque is 1.7 N.m — use a flat Ø 6 mm, Philips No 2, or Pozidriv No 2 screwdriver.
The block carries approvals under EN/IEC 60947-5-1, GB/T 14048.5, EN 50012, UL 60947-5-1, and CSA C22.2 No 60947-5-1. It also meets the glow-wire and hot-wire requirements of IEC 60335-1 Clause 30.2 and the specific requirements of IEC 60335-2-40 Annex JJ for HVAC equipment. Protective treatment is TH conforming to IEC 60068 for tropical environments.
Dimensions and environment
Dimensions are 48 mm high, 44 mm wide, and 42 mm deep. Maximum operating altitude is 3000 m.