The Schneider Electric VW3L40020 is an insert for the communication interface of Lexium integrated drives, providing the physical connection for the Safe Torque Off (STO) safety function. It carries two STO signal paths, each terminated to a separate M8 4-pin connector — one female, one male — so the safety circuit can be daisy-chained or looped back through the drive without a separate junction box. The kit includes one sealing insert and one insert with connectors, ready for panel-side wiring.
What the STO connection means for the line
Two STO signals means this insert supports dual-channel safety architecture — the standard for SIL 3 / PL e circuits where a single fault must not lead to loss of the safety function. Each M8 4-pin connector carries the 24 VDC signal pair and the return, so the drive's STO inputs are isolated from the safety relay or PLC output. In a Lexium integrated drive application (a compact servo or motor-drive combo), this insert replaces the need to hard-wire into the drive's main control connector, keeping the safety wiring segregated and serviceable.