Intermediate relay common fault handling method - Database & Sql Blog Articles

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An intermediate relay is a type of control relay commonly used as an auxiliary component in electrical circuits. It is especially useful when the control circuit requires a large number of contacts or higher capacity, allowing for signal amplification or increasing the number of control loops. When the coil voltage reaches the specified level, the intermediate relay activates and performs its function. Since the construction of an intermediate relay is similar to that of a contactor, many of the common issues, diagnostic methods, and solutions related to contact problems and electromagnetic systems can be referenced from contactor guidelines. However, one key difference is that intermediate relays are more prone to false connection faults. These issues often occur during normal operation and may not happen consistently, making them difficult to detect and diagnose. When such faults do occur, they can lead to serious consequences. The root cause of this problem is usually due to a drop in the actual voltage across the coil of the electromagnetic device, which falls below 85% of the rated voltage. This can happen due to changes in contact resistance within the control circuit, preventing the core from being properly attracted and causing a loss of control in the circuit. To minimize the risk of these failures, consider the following best practices: (1) Avoid using voltages of 12V or lower as the control voltage whenever possible, as low-voltage circuits are more susceptible to false connections. (2) If 24V is used as the control voltage, it's recommended to use parallel contact configurations to improve reliability. (3) If low voltage is unavoidable, 48V is a better option than lower voltages. (4) Whenever possible, use a control voltage of 110V or higher. This significantly reduces the chance of contact false connections and ensures more stable operation. By following these guidelines, you can enhance the performance and safety of your control systems, especially in critical applications where reliability is essential.