The **FNS-4W1-R** is a specific model of a **water leak detection sensor** (often manufactured by companies like FineTek). It is designed to detect the presence of conductive liquids (water) to prevent damage in sensitive environments like data centers, laboratories, or industrial facilities. --- ### 1. Key Technical Specifications The following table outlines the primary electronic and physical characteristics of the FNS-4W1-R sensor: | Feature | Specification | | :--- | :--- | | **Detection Method** | Electrical Conductivity (Leak sensing cable) | | **Input Voltage** | 12V to 24V DC | | **Power Consumption** | Low (approx. 30-50mA depending on state) | | **Output Signal** | Relay Contact (SPDT) - Normal Open/Normal Closed | | **Contact Rating** | 1A @ 24VDC or 0.5A @ 125VAC | | **Response Time** | < 1 second | | **Operating Temperature** | -20°C to +75°C | --- ### 2. Main Electronic Components The device functions as an interface module that connects a sensing cable to a monitoring system (PLC or Alarm). * **Sensing Interface:** Uses a weak electrical current sent through a specialized sensing cable. When water touches the cable, it completes a circuit (bridging the gap between wires), which the electronic module detects. * **Signal Processor:** An internal IC analyzes the resistance change. It is designed to distinguish between actual leaks and high humidity to prevent false alarms. * **Relay Output:** The "R" in the model name typically signifies a **Relay** output. This allows the device to act as a switch to trigger external sirens, shut off valves, or notify a Building Management System (BMS). * **LED Indicators:** * **Power LED:** Indicates the module is receiving DC power. * **Alarm/Leak LED:** Lights up when a leak is detected or when there is a continuity break in the sensing cable. --- ### 3. Wiring Configuration The unit typically features a terminal block for easy integration: ```markdown Terminal 1-2: Power Input (V+ and V-) Terminal 3-4: Sensing Cable Input Terminal 5-6-7: Relay Outputs (Common, NO, NC) ``` --- ### 4. Applications The FNS-4W1-R is commonly integrated into the following systems: 1. **Server Rooms:** Placed under raised floors to detect A/C condensation leaks. 2. **Clean Rooms:** Monitoring chemical or water transport lines. 3. **Basements/Storage:** Protecting high-value inventory from flooding.