The LA9FL4J4F is a mechanical interlock from the TeSys F range, designed to prevent simultaneous closure of up to three vertically stacked contactors — a standard safety practice for reversing or dual-speed motor starters where both contactors must never energize at the same time. The interlock physically blocks the armature of one contactor while the other is pulled in, so even a welded main contact or a stuck coil cannot create a phase-to-phase short across the load.
Which Contactors It Fits
This accessory mounts in a 3-vertical stack and interlocks the following combinations: bottom position accepts LC1F115 through LC1F150 (3P or 4P) or CR1F150 (3P or 4P); middle position accepts LC1F400 (2P, 3P, or 4P) or CR1F400 (3P or 4P); top position accepts LC1F630 (3P or 4P), LC1F800 (3P), or CR1F630 (3P or 4P). That means you can mechanically interlock a small reversing pair (e.g., two LC1F115s) or a three-contactor star-delta or dual-speed starter with mixed frame sizes — the same LA9FL4J4F covers the spread.
Sourcing is straightforward — specify this order code against an RFQ for quoted delivery.