The LiftMaster LMPDT24-2W is a 2‑wire photoelectric and thermal smoke detector engineered for use with LiftMaster fire door release systems and other compatible conventional control devices that support 2‑wire initiating circuits. Combining photoelectric smoke sensing for early detection of smoldering fires with an integrated thermal element for heat alarm conditions, this detector helps provide reliable notification to trigger automatic closure of rolling steel fire doors and shutters in commercial and industrial applications. Its 2‑wire design simplifies wiring by carrying both power and alarm signaling on the same loop, typically from a 24 VDC source supplied by the supervising release device or panel.
Intended as a replacement part or upgrade for LiftMaster fire door accessories, the LMPDT24-2W installs on a compatible base and connects to a supervised 2‑wire circuit per the wiring diagram of the LiftMaster release device or listed fire alarm control. Use in dry, indoor locations and follow NFPA 72 and local code requirements. Final compatibility, loop capacity, and end‑of‑line supervision must be confirmed with the specific LiftMaster control or release device documentation before installation. Testing and commissioning should be performed by qualified life‑safety professionals using approved functional test methods.