The **KAC-ACD-R** is an addressable manual call point (MCP) designed specifically for fire alarm systems using the **System Sensor/Notifier** protocol. It is an electronic component that allows building occupants to manually trigger a fire alarm by pressing or breaking a front element. --- ### 1. Key Electronic Components & Specifications The KAC-ACD-R is more than just a mechanical switch; it contains integrated circuitry to communicate with a Fire Alarm Control Panel (FACP). | Component | Technical Detail | | :--- | :--- | | **Communication Protocol** | Advanced/Analogue Addressable (System Sensor) | | **Operating Voltage** | 15V to 32V DC (Powered by the SLC Loop) | | **Current Consumption** | ~200μA (Standby) / ~7mA (Alarm - LED on) | | **Addressing** | Rotary Switches (01-159) or Digital Addressing | | **Indicator** | Tri-color LED (Red for Alarm, Green for Polling) | | **Termination** | Plug-and-play terminal blocks (up to 2.5mm² wire) | --- ### 2. Functional Electronic Features #### A. Rotary Address Switches Unlike conventional switches, the KAC-ACD-R features two rotary dials on the back of the electronic module. These are used to set a unique decimal address (e.g., 01, 15, 99). This allows the control panel to identify exactly which device has been activated. #### B. Integrated Logic Circuitry The internal PCB (Printed Circuit Board) handles: * **Polling:** Responding to the control panel's status requests. * **Interrupt Function:** When activated, the device sends an immediate "interrupt" signal to the panel, ensuring a response time of less than 3 seconds. * **Built-in Isolator (Optional):** Some versions include a short-circuit isolator to protect the rest of the loop if a cable fault occurs. #### C. LED Status Signaling The electronics drive a high-visibility LED: * **Blinking Green:** Normal operation (polling). * **Steady Red:** Alarm condition. * **Yellow/Amber:** Fault or isolation (on specific models). --- ### 3. Connection Diagram Overview The electronic interface uses a simple two-wire connection to the Signaling Line Circuit (SLC): ```text [Loop In +] ---- (1) [Loop In -] ---- (2) Internal Circuitry --- [Rotary Switches] [Loop Out +] ---- (3) | [Loop Out -] ---- (4) [Bi-color LED] ``` --- ### 4. Environmental & Physical Characteristics * **IP Rating:** Typically IP24D (Indoor use). * **Material:** Flame retardant ABS plastic. * **Plug-and-Play:** The "E-Z Fit" connector allows the backbox to be wired independently of the electronic front element, preventing damage to the PCB during construction. ---