Allen-Bradley 440G-T27171 Guard Locking Switch

The Allen-Bradley 440G-T27171 Guard Locking Switch is a TLS-GD2, power-to-release guard interlock (TLS-1 GD2) designed for safeguarding machine access doors on automation lines. It operates from a 24 V AC/DC solenoid to release the lock and includes solenoid contacts: one normally closed and one normally open, plus safety/auxiliary contacts: two normally closed and one normally open, all wired through a Fully-Flex actuator with a 1/2 in NPT conduit entry. As part of the Series E 440G TLS-GD2 family, it delivers up to 2000 N (about 450 lb) of holding force to secure the guard until a safe-release condition is achieved. Typical applications include guarding interlocks on presses, robotic cells, and other automated machinery where a guard must be mechanically locked and electronically monitored before equipment can operate, with the auxiliary contact providing status feedback for control systems.