How to Deal with the Trip Fault of Frequency Converter
The emergence and application of frequency converter simplifies the complex control and makes the production process more convenient and fast. However, like other control devices, the frequency converter will inevitably fail in application. In the process of using frequency converter, frequency converter tripping is a common fault. When the converter has such a fault problem, how can we deal with it quickly? Today, Meijiewei will introduce in detail the common trip fault treatment methods of the converter:
1. Handling of power failure
If the power supply instantaneous power off or voltage drop appears "undervoltage" display, or instantaneous overvoltage appears "overvoltage" display, it will cause the frequency converter tripping and shutdown, and can restart after the power supply returns to normal.
2. External Fault Handling
If the input signal is open, the output line is open, phase-broken, short-circuit, grounding or insulation resistance is very low, motor fault or overload, etc., the frequency converter shows "external" fault and trips and stops, after eliminating the fault, it can be re-activated.
3. Internal Fault Handling
If the internal fan is broken or overheated, the fuse is broken, the device is overheated, the memory is wrong, the CPU fault, etc., can be switched to the power frequency operation first, without affecting the production, after the internal fault is eliminated, the frequency conversion operation can be restored.
In case of internal failure of frequency converter, if it occurs during the warranty period, the manufacturer or the manufacturer's agent should be notified to take charge of the warranty.
The following checks are performed according to the categories and data displayed by the fault:
After opening the chassis, first observe whether there are broken wires, virtual welding, burning odor or metamorphic and deformed components in the chassis. If so, they should be handled in time.
Multimeter is used to detect resistance value and on-off resistance of diode, switch and module to judge whether it is on or off. If yes, replace it with original nominal value and withstand voltage value, or replace it with the same type.
Dual tracer oscilloscope is used to detect the waveform of each working point, and step by step elimination method is used to judge the fault location and components.
The problems that should be paid attention to in overhaul are as follows:
Strictly prevent virtual welding, virtual connection, or wrong welding, continuous welding, or wrong wiring, especially do not mistake the power cord to the output terminal.
Power-on static check whether the indicator lights, digital tubes and display screen are normal, and whether the preset data is appropriate.
If conditions permit, a small motor can be used for simulation dynamic test.
4. Disposal of improper setting of function parameters
When the parameters are preset, the no-load test is normal and the "over-current" tripping occurs after loading, which may be due to insufficient setting of starting torque or insufficient acceleration time. Others operate for a period of time, the moment of inertia decreases, resulting in "over-voltage" tripping during deceleration, modifying the functional parameters, and appropriately increasing the acceleration time can be solved.