The **E5C2-R20J** is a popular analog temperature controller manufactured by Omron. It is widely used in industrial applications such as packaging machines, ovens, and plastic molding due to its simplicity and reliability. --- ## 1. Technical Specifications Table The following table summarizes the key electrical and mechanical specifications of the E5C2-R20J: | Feature | Specification | | :--- | :--- | | **Input Type** | J-type Thermocouple (Fe-CuNi) | | **Control Mode** | ON/OFF Control | | **Supply Voltage** | 100 to 240 VAC (50/60 Hz) | | **Power Consumption** | Approx. 2 VA | | **Control Output** | Relay Output (SPDT) | | **Relay Rating** | 3A at 250 VAC (Resistive Load) | | **Setting Accuracy** | ±2% of Full Scale | | **Mounting** | 8-pin Round Socket (DIN rail or panel) | | **Standard Dimensions** | 48 x 48 mm (1/16 DIN) | --- ## 2. Key Electronic Components & Features ### A. The Input Stage (Thermocouple Interface) The "J" in the model name indicates it is calibrated specifically for **J-type thermocouples**. - It uses internal **Cold Junction Compensation (CJC)** to ensure that temperature readings remain accurate even as the ambient temperature at the controller terminals changes. ### B. The Control Logic (ON/OFF) Unlike modern PID controllers, the E5C2 series uses a simpler **ON/OFF control** mechanism: - When the temperature is below the set point, the relay is energized (ON). - Once the temperature reaches the set point, the relay de-energizes (OFF). - It features a small built-in **hysteresis** (differential) to prevent the relay from "chattering" (rapidly switching) when the temperature is exactly at the set point. ### C. Output Mechanism (Electromechanical Relay) The controller features a physical relay output. - **Terminals:** Usually involves a Common, Normally Open (NO), and Normally Closed (NC) contact. - **Life Expectancy:** Mechanical life is roughly 10 million operations; Electrical life is roughly 100,000 operations at rated load. ### D. User Interface - **Setting Dial:** A manual analog potentiometer allows the user to set the target temperature. - **LED Indicators:** Typically features a red LED to indicate when the output relay is active. --- ## 3. Wiring Configuration (8-Pin Base) To use the E5C2-R20J, it must be plugged into an 8-pin socket (like the Omron P2CF-08). The standard pinout is usually: 1. **Pin 1 & 8:** Power Supply (100-240 VAC). 2. **Pin 3, 4, 5:** Relay Output (Common, NO, NC). 3. **Pin 6(+) & 7(-):** Thermocouple Input (Observe polarity). --- ## 4. Selection Guide Ensure that the "R20J" version matches your needs: - **R:** Relay Output. - **20:** Fixed code related to series generation/features. - **J:** Specifically for J-type Thermocouples (K-type thermocouples will not work correctly with this unit).