SDC 492 Emergency Door Release Pull Station, Siren, Single-Gang, Blue, DPDT

The SDC 492 is a blue emergency door release pull station with a built-in audible siren and dual SPDT 10-amp contacts designed to immediately unlock doors equipped with fail-safe electric locking hardware. Part of the SDC 490 Series, it features a pull-down T-handle, operates its internal alarm on 3-28 VDC, and provides auxiliary contacts for remote monitoring, CCTV activation, or alarm signaling. The 492 supports single-gang or surface mounting and includes two replacement glass rods.

SDC 492 Emergency Door Release Pull Station with Siren

The SDC 492 Emergency Door Release Pull Station is a manually operated emergency egress device designed to immediately release fail-safe electric door locks during emergency situations. Part of the Security Door Controls (SDC) 490 Series, the 492 provides a dedicated manual release point for perimeter doors, interior access-controlled openings, and secured exits. Its distinctive blue housing features clearly marked "DOOR RELEASE EMERGENCY," "PULL DOWN," and "ALARM WILL SOUND" instructions, helping occupants distinguish the emergency door release station from conventional red fire alarm pull stations. When activated, the pull-down mechanism changes the switch contacts to interrupt the locking circuit and can trigger an integrated audible siren to provide local notification.

The SDC 492 incorporates two single-pole, double-throw (SPDT) switch contacts rated at 10 amps, providing separate circuits for emergency lock release and auxiliary signaling. One SPDT contact is dedicated to releasing compatible fail-safe electric locks, while the second supports remote monitoring, CCTV activation, or external alarm signaling. The built-in siren operates on 3-28 VDC with a nominal current draw of 18 mA, allowing the station to provide audible notification when connected to a suitable power source. Depending on the electrical configuration, the device can initiate the release of an individual door or multiple doors connected to the same release circuit, supporting centralized emergency unlocking in access control installations.

The SDC 492 features a compact housing measuring 4.75 inches high, 3.25 inches wide, and 1.375 inches deep, making it suitable for installation near access-controlled exits and emergency egress points. The station mounts to a 2-inch-deep single-gang electrical back box or a double-gang box with a plaster ring cover. Surface mounting is also supported using the optional SDC 492-BB blue back box. Its mechanical pull-down T-handle incorporates a replaceable glass rod that must be replaced after activation to restore the station to its normal condition. Two replacement glass rods are supplied with the unit, and additional rods are available separately as the SDC 492-GL4 replacement glass rod kit. The front cover opens with an Allen wrench to provide access for resetting the handle and replacing the glass rod.

The SDC 492 is designed for commercial buildings, warehouses, technology facilities, institutional properties, and other locations requiring emergency release of electrically secured doors. It integrates with compatible fail-safe electromagnetic locks and other electric locking systems that release when their locking power is interrupted. The 490 Series carries a UL 38 listing for manual signaling boxes, and the 492 is identified in SDC documentation as an emergency door release device with California State Fire Marshal listing information. Its blue identification housing, dual-contact switching, integrated audible notification, and flexible mounting options make the SDC 492 suitable for both new access control installations and upgrades to existing electronically secured openings. Installation must comply with applicable building, fire, and life-safety requirements governing emergency egress.