The **AS4LC-S12-R/Q** is a specific type of **Electromechanical Power Relay** manufactured by ASCO (or similar OEM brands often used in specialized industrial and HVAC applications). These relays are designed to control high-power circuits using a low-power signal. Below is a detailed breakdown of its electronic components and specifications. ### 1. Component Identification The alphanumeric code typically breaks down into the following technical segments: | Segment | Meaning | Description | | :--- | :--- | :--- | | **AS4L** | Series Code | High-capacity power relay series. | | **C** | Contact Form | Usually indicates **SPDT** (Single Pole Double Throw) or changeover contacts. | | **S** | Sealing Type | Sealed construction (wash-tight), protecting internals from dust/moisture. | | **12** | Coil Voltage | Designed for a **12V DC** input signal. | | **R/Q** | Terminal/Mounting | Indicates specific pin layouts (PCB vs. Quick Connect) and ROHS compliance. | --- ### 2. Technical Specifications These parts are engineered for switching significant loads, often found in automotive or industrial control boards. | Feature | Specification (Typical) | | :--- | :--- | | **Coil Voltage** | 12V DC | | **Contact Rating** | 30A to 40A at 14V DC (Automotive) or 120V AC | | **Contact Material** | Silver Alloy (AgSnO2) for arc resistance | | **Dielectric Strength** | 500V - 1000V AC between open contacts | | **Operating Temp** | -40°C to +85°C | --- ### 3. Internal Construction The device consists of four primary electronic/mechanical elements: 1. **The Coil:** A copper wire winding that creates a magnetic field when 12V DC is applied. 2. **The Armature:** A moving metal piece attracted by the magnetic field of the coil. 3. **Spring Mechanism:** Returns the armature to its "rest" position when power is removed. 4. **Contacts:** The high-current points that physically touch to complete the electrical circuit. --- ### 4. Common Applications * **HVAC Systems:** Controlling fan motors or compressors. * **Automotive Electronics:** Power windows, fuel pumps, or lighting systems. * **Industrial Automation:** Interfacing low-voltage microcontrollers (like Arduino or PLC) with high-voltage machinery. --- ### 5. Wiring Diagram Logic If you are looking at the bottom of the relay, the pins generally follow this logic: ```text Pin 85 & 86: Coil Input (12V DC) Pin 30: Common (Power Input) Pin 87: Normally Open (NO) - Connects when coil is powered Pin 87a: Normally Closed (NC) - Disconnects when coil is powered ```