Hello, everyone~ Relays are widely used. If you use relays frequently, you will definitely encounter relay failures. The editor has sorted out 4 common causes of internal relay failures. Come and see if you have encountered them.
Coil failure
Relay coil failure is common in the following situations: external reasons (overvoltage, ultrasonic cleaning, etc.) cause the relay coil to break and cause the failure; if the voltage supplied to the coil is lower than the operating voltage, the coil power supply is insufficient, which will also cause the relay to fail; built-in If the polarity of the coil of a diode-type relay is reversed, the contacts will not operate; in addition, if the coil is energized for a long time, the coil part will be in a high temperature state, which will cause the coil to be damaged.
Countermeasures: When selecting a relay, you should confirm in advance whether the coil voltage meets the supply voltage under the application environment, and ensure that the correct polarity is connected. During use, avoid energizing the relay coil for a long time if it is not necessary.
Contact adhesion
Overcurrent, switching frequency exceeding the rated switching frequency of the relay, abnormal vibration of the contact part, etc. may cause contact sticking.
Countermeasures: In the case of ensuring the quality of the relay, in order to avoid sticking, consider choosing a relay with a large contact capacity and a large switching frequency when selecting a relay. It is safer to use solid state relays.
Poor contact
Corrosion or damage to the contact surface, unstable coil energization voltage, dust and other foreign objects attached to the contact surface, or severe vibration in the environment where the relay is used may cause poor contact.
Countermeasures: According to different reasons, consider replacing a stable power supply, or choose a dust-proof, sealed or higher seismic resistance relay. At the same time, consider the effect of arc, and choose a relay product with an arc extinguishing device;
Light does not shine
When the coil power supply is insufficient, the coil DC power supply or the polarity connection is reversed, it may cause the relay indicator light to malfunction.
Countermeasures: First of all, it is necessary to determine what kind of reason is causing the indicator lamp failure, and insufficient coil power supply will cause the entire relay to fail. However, the coil is powered by DC and the polarity is reversed, the relay contacts can operate and the indicator light does not light up. According to different situations, choose to replace the relay or change the two-pole wiring.
