The **KAC-ADG-R** is an addressable manual call point (break glass unit) designed specifically for fire alarm systems using the **System Sensor/Morley-IAS** protocol. Below is a detailed breakdown of its electronic components and specifications. --- ### 1. Core Technical Specifications The device operates as an intelligent peripheral on a 2-wire signaling line circuit (SLC). | Component/Feature | Specification | | :--- | :--- | | **Operating Voltage** | 15V to 30V DC (Peak) | | **Quiescent Current** | ~385μA @ 24V (No LED blink) | | **Alarm Current** | ~7.6mA (Red LED solid) | | **Communication Protocol** | Analog Addressable (Proprietary) | | **Wiring Terminal** | 0.5mm² to 2.5mm² | --- ### 2. Electronic Hardware Components #### A. The PCB (Printed Circuit Board) The heart of the unit is a small internal PCB that handles the digital communication between the manual trigger and the Fire Alarm Control Panel (FACP). * **Microcontroller/ASIC:** Manages the unique address of the device and monitors the status of the switch. * **Addressing Switches:** Most KAC addressable units use **Rotary Decade Switches** (01-99 or 01-159). These allow the technician to manually set the address using a small screwdriver. #### B. The Activation Mechanism * **Microswitch:** Unlike a simple mechanical switch, this is integrated into the monitoring circuit. When the "glass" (or flexible element) is pressed, the circuit state changes from "Normal" to "Active." * **Monitoring Resistors:** Used to supervise the internal circuitry for faults, ensuring the panel knows if the internal wiring of the call point has failed. #### C. Visual Indicators (LEDs) * **Tri-Color/Bi-Color LED:** * **Blinking Green:** Indicates the device is polling (communicating) with the panel. * **Solid Red:** Indicates an alarm condition (the unit has been activated). * **Yellow:** Often indicates a fault or an isolation state (if the built-in isolator is active). #### D. Built-in Line Isolator Many versions of the KAC-ADG-R include an **Integrated Short Circuit Isolator**. This electronic sub-circuit monitors the data loop. If a short circuit occurs on the wire, the isolator opens the circuit to prevent the entire loop from failing, allowing devices on the other side to continue functioning. --- ### 3. Wiring Diagram Overview The electronics are connected via a plug-and-play terminal block to simplify installation. ```text Loop In (+) ---- [ Terminal 1 ] Loop Out (+) ---- [ Terminal 2 ] Loop In (-) ---- [ Terminal 3 ] Loop Out (-) ---- [ Terminal 4 ] ``` --- ### 4. Key Electronic Features * **Plug-and-Play:** The terminal block can be wired independently of the main electronic head, protecting the PCB from damage during construction. * **Digital Filtering:** The internal electronics include noise filters to prevent "ghost" alarms caused by electromagnetic interference (EMI) from nearby power cables.