The **E5C2-R40GD** is a basic, analog-set temperature controller manufactured by Omron. It is widely used in industrial applications for simple ON/OFF control tasks where a digital interface is not required. --- ### 1. Technical Specifications The E5C2 series is known for its DIN 48 x 48 mm compact size and plug-in mounting system. | Feature | Specification | | :--- | :--- | | **Control Type** | ON/OFF Control | | **Input Type** | Thermocouple (usually Type K or J, check specific suffix) | | **Output Type** | Relay Output (SPDT) | | **Supply Voltage** | 100 to 240 VAC (50/60 Hz) | | **Setting Method** | Analog Dial (Potentiometer) | | **Mounting** | 8-pin Round Socket (Surface or Flush mounting) | | **Power Consumption** | Approx. 2 VA | --- ### 2. Key Electronic Components & Terminals The device operates using a set of internal electronic circuits that compare the sensor voltage to a reference voltage set by the dial. #### A. Internal Operation * **Comparator Circuit:** The core electronic part that compares the millivolt signal from the thermocouple against the internal reference voltage determined by the front dial position. * **Relay Mechanism:** An electromagnetic switch that activates when the measured temperature is below the set point and deactivates when it exceeds it (for heating control). #### B. Terminal Configuration (8-Pin) The E5C2 uses a standard circular 8-pin layout: | Pin Number | Function | Description | | :--- | :--- | :--- | | **1 & 8** | Power Supply | 100-240 VAC Input | | **4, 5, 6** | Relay Output | 4 (Common), 5 (NC), 6 (NO) | | **7 (+), 8 (-)** | Sensor Input | Connection for the Thermocouple | --- ### 3. Electronic Characteristics * **Hysteresis:** The unit has a fixed "differential" or hysteresis (usually around 0.5% of the full scale). This prevents the relay from "chattering" or rapidly switching on and off when the temperature is exactly at the set point. * **Cold Junction Compensation:** Even as an analog device, it includes internal circuitry to compensate for the ambient temperature at the controller terminals, ensuring accurate thermocouple readings. * **Indication LEDs:** * **PW (Green):** Indicates power is supplied to the unit. * **OUT (Red):** Indicates the control output (relay) is energized. --- ### 4. Application Considerations * **Analog Precision:** Unlike digital controllers (PID), the E5C2 is prone to "overshoot" because it uses simple ON/OFF logic. * **Calibration:** The accuracy is dependent on the dial alignment. It is best suited for processes that can tolerate a few degrees of variance. * **Socket Requirement:** It requires an **P2CF-08** (front-connecting) or **P3G-08** (back-connecting) socket for installation.