Stellar 11938 F3SE3170 Anti-Two-Block Limit Switch

If you’re unsure whether this part is compatible with your truck or equipment, please contact us to confirm fitment before purchasing.

The Stellar 11938 Limit Switch is a genuine OEM anti-two-block safety switch designed for compatible Stellar mechanic service cranes. Identified by switch model F3SE3170, it mounts near the boom tip and works with the crane’s weight-and-chain anti-two-block system.

If the hook block or overhaul ball approaches the boom tip, the system activates this switch to interrupt the affected crane function. This helps prevent the load-handling components from being pulled into the boom tip, which can damage the wire rope, sheaves, winch, or crane structure.

What This Part Is Used For

The Stellar 11938 switch monitors the position of the anti-two-block weight near the crane’s boom tip. When the lifting line is reeled in too far, the weight activates the switch and signals the crane-control system to stop the hazardous movement.

Common Reasons For Replacement

Anti-two-block system does not activate
Crane displays an A2B fault
Winch-up function remains disabled
Switch sticks in the open or closed position
Damaged switch housing or actuator
Corroded or broken electrical connections
Impact or weather damage near the boom tip
Failed continuity or electrical testing

Key Features

OEM Stellar Industries part number 11938
F3SE3170 limit-switch configuration
Anti-two-block safety-system component
Mounts near the crane boom tip
Works with weight-and-chain-style A2B systems
Helps prevent wire-rope and boom-tip damage
Direct replacement for compatible factory-installed switches