Common fault diagnosis of non-standard automatic machines

Common fault diagnosis of non-standard automatic machines

1. Check all power, air, and hydraulic sources.
The gas source includes the source of air pressure required for the pneumatic device. The hydraulic source includes the operation of the hydraulic pump required by the hydraulic unit. In the 50% troubleshooting problem, basically the error is the problem of power or gas source and hydraulic source. If there is a problem with the power supply, including the fault of the entire workshop power supply, such as low power supply, burned out of the insurance, poor contact of the power plug, etc.; the air pump or hydraulic pump is not turned on, the pneumatic triple or two-piece is not open, and the relief valve in the hydraulic system Or some pressure valves are not open, etc. These basic problems are usually the most common ones.
2. Check the sensor position for an offset.
Due to the negligence of equipment maintenance personnel, there may be errors in the position of some sensors, such as not in place, sensor failure, sensitivity failure, etc. Always check the sensor's sensing position and sensitivity, and adjust the deviation in time. If the sensor is broken, replace it immediately. Many times, if the power supply, air supply and hydraulic source are supplied without errors, more problems are the sensor failure. Especially for magnetic inductive sensors, due to long-term use, it is very likely that the internal grounding irons stick to each other, cannot be separated, and a normally closed signal appears, which is also a common problem of this type of sensor and can only be replaced. In addition, due to the vibration of the equipment, most of the sensors will have a loose position after long-term use. Therefore, during routine maintenance, always check whether the sensor is in the correct position and is firmly fixed.
3. Check relay, flow control valve, pressure control valve
Like the magnetic inductive sensor, the relay can also be stuck in the long-term use, so that the electrical circuit cannot be guaranteed to be normal and needs to be replaced. In pneumatic or hydraulic systems, the throttle opening and the pressure regulating spring of the pressure valve may also loosen or slide as the device vibrates. These devices, like sensors, are components in the device that require routine maintenance. Therefore, in daily work, these devices must be carefully checked.
4. Check electrical, pneumatic and hydraulic circuit connections
If no problems are found in the above three steps, then all circuits are checked. Check if there is any open circuit in the circuit, especially if the wire in the wire slot is broken by the wire slot. Inspect the air tube for damaging creases. Check if the hydraulic hose is clogged.
When checking the circuit at this step, use the necessary multimeter, adjust to the buzzer file, and check the path of the loop. If the trachea has a serious crease, replace it immediately. The hydraulic tubing should be replaced.
5. After ensuring that the above steps are correct, the fault may appear in the controller, but it can never be a program problem! First of all, don't be sure that the controller is destroyed. As long as there is no serious short circuit, the controller has short-circuit protection inside. The general short circuit will not burn the controller.
First, check if there is a device with high frequency interference near the controller. If so, move away immediately. If outdoors, high-intensity lightning can also cause the controller to not work properly in an instant. In this case, first remove all possible interfering devices and then restart the controller.
Secondly, if the restart is invalid, check if the controller wiring is loose and there is a bad contact.
Finally, if the wiring is correct. Determine if there is a problem with the memory card of the PLC. Replace a new card and download the program to check if the previous memory card is faulty.