Guardmaster 440G

The Allen-Bradley Guardmaster 440G is a broad family of safety interlock and guard-locking switches designed to monitor and control access to hazardous machine areas, spanning solid-state guard locking (440G-MZ/LZ), electromechanical TLS-GD2 guard locking, heavy-duty solenoid interlocks (440G-MT), hinge interlocks (440H Sprite and Ensign 3), trapped-key systems (440T), and the multifunctional 442G access box — more than 200 catalog numbers in total. Catalog-number structure varies by sub-family: for TLS-Z solid-state variants, positions encode contact configuration (e.g., 20 = two safety, no aux), coding type (S=standard, U=unique), lock action (R=Power to Release, L=Power to Lock), connector style, and optional escape release; for 440G-MT heavy-duty solenoid switches, the five numeric digits encode solenoid voltage, contact arrangement, actuator type, and conduit entry; for 440G-LZ actuators, the suffix identifies coding and lock action — for example, 440G-LZAUPL is a unique-coded, Power-to-Lock spare actuator. Popular in-stock items include the 440G-T27181 (TLS GD2, Power to Release, 24V AC/DC, 2 N.C.) and 440G-TZS21UPRH (TLS-Z GD2, Power to Release, 24V DC, 2 N.C. safety contacts). Consult the Guardmaster 440G Safety Switch Technical Data for full selection guidance.