SDC Delay Switches

Overview

The SDC Security Door Controls MD-31DOW is a motion detector with a built-in time delay function, finished in off white. Designed for use in access control and door management systems, this unit detects occupant movement to trigger door releases, electric strikes, or other low-voltage control circuits. The time delay feature holds the output signal for a set period after motion is no longer detected, preventing nuisance cycling in high-traffic entryways. Installation is typically performed by a licensed access control or low-voltage technician as part of a broader door hardware or security system integration. The MD-31DOW is suited for commercial and light-industrial interior doorway applications where automatic or hands-free door activation is required. Common install scenarios include vestibules, corridors, and secured entryways where a passive infrared or similar sensing element monitors an approach zone and feeds a signal to the door control system. The off white finish is consistent with standard commercial interior finishes for low-profile installations. Key Features Integrated time delay output holds signal after motion ceases, reducing nuisance door cycling Off white finish blends with standard commercial interior wall and ceiling surfaces Designed for connection to low-voltage access control and door release circuits Single-unit construction suitable for surface mounting in door approach zones Sold as an individual unit for direct replacement or new installation…