York S1-D4P120 Board Power Smoke Detector Duct

The York S1-D4P120 Board Power Smoke Detector Duct is an electronic control module used in duct smoke detection systems within installations. It supplies operating power and manages signal processing for the duct smoke detector assembly, enabling monitoring of airflow passages for smoke presence within HVAC systems. When smoke is detected inside the ductwork, the board interfaces with the control circuit to trigger fan shutdown or alarm signaling, depending on system configuration. It is commonly placed in commercial air handling units and building ventilation systems where duct-mounted smoke detection is required to maintain controlled air distribution and system response during fire safety events.