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 systems. It is particularly useful when the control circuit requires a large number of contacts or higher current capacity. By acting as a signal amplifier or increasing the number of control loops, it helps manage complex control tasks efficiently. When the coil voltage reaches the specified level, the intermediate relay activates and performs its function. The design of an intermediate relay is similar to that of a contactor, so many of the common issues related to contacts and electromagnetic components can be addressed using the same diagnostic methods as those for contactors. However, one specific issue often associated with intermediate relays is "false connection" or "contact sticking." This problem typically occurs during system operation and may not happen regularly or predictably, making it challenging to detect and diagnose. When it does occur, it can lead to serious malfunctions or even system failures. The root cause of this issue is usually a drop in the actual voltage across the coil, which falls below 85% of the rated voltage. This can happen due to changes in the contact resistance within the control circuit, preventing the core from being properly attracted. As a result, the circuit loses control, leading to unexpected behavior. To prevent such faults, consider the following best practices: (1) Avoid using low voltages like 12V or lower as the control voltage. These voltages are more prone to causing false connections due to unstable contact performance. (2) If 24V is used as the control voltage, it's recommended to use parallel contact configurations to improve reliability and reduce the risk of failure. (3) In cases where low-voltage control is necessary, 48V is a better choice than 12V or 24V, as it provides a more stable operating environment for the relay. (4) Whenever possible, use a control voltage of 110V or higher. This significantly reduces the likelihood of contact false connections and ensures more consistent and reliable operation. By implementing these measures, you can greatly enhance the stability and safety of your control systems, especially in industrial or critical applications where relay performance is crucial.