If you frequently repair a certain brand or several brands of inverters, you should have the terminal diagram of the connection cable between the CPU motherboard and the power/driver board. With it, the maintenance efficiency will be greatly improved. I spent a lot of effort to survey and map the terminal diagrams of the CPU motherboards of three inverters. I…
Year: 2024
Based on the overall circuit of the VFD (Variable Frequency Drive), there are two malfunctions.
(A) Power Supply Fault Inspection: Fault Status: After powering on, the entire device does not respond, and the operation display panel shows no display. The measured 24V and 10V control power at the control terminals are both 0V. Fault Essence: The VFD’s switching power supply is not working. Troubleshooting Approach: (1) Switching voltage fault; (2) Pre-charging circuit fault. Troubleshooting Method:(1)…
The repair process of an unlicensed VFD caught up with lightning speed
In movies and TV shows, when a Taoist from Maoshan encounters an urgent and difficult situation, he often recites a curse: “The Supreme Old Lord is as sick as a law… If something difficult happens, it should be solved by the curse.”. If there is an urgent VFD repair, we can also recite a few mantras and find the “smart”…
Analog circuits used in VFD fault detection circuits
The main circuit of the fault detection circuit is still composed of an operational amplifier. Usually, the operational amplifier is connected to the following types of circuits, completing three tasks of signal analog amplification, comparative output, and precision rectification.(A)、 Inverting amplifier circuit: Operational amplifier reverse amplification circuit An operational amplifier has excellent characteristics such as high input impedance (without using…
How to conduct load testing on VFD drive circuits to solve the problem of normal no-load and load failure?
The voltage amplitude of the six driving pulses outputted by the driving circuit meets the requirements. For example, measuring the amplitude of the positive excitation pulse voltage in the AC range is about 14V, and the amplitude of the negative cutoff voltage is about 7.5V (different models may vary). After the above inspection of the driving circuit, most maintenance personnel…
Maintenance ideas and methods for VFD switching power supply
The switching power supply circuit of VFD can be completely simplified into the circuit model shown in the diagram, and the key elements in the circuit are included. And any complex switching power supply, after removing the branches, will still have a backbone like the one shown in the picture. In fact, in maintenance, it is necessary to have the…
Communication Application of Mitsubishi FX2NPLC and Mitsubishi VFD ModbusRTU Protocol
Modbus is a serial communication protocol invented by Modicon for the communication between its PLC and the host. Its physical layer adopts asynchronous serial standards such as RS232 and 485. Due to its openness, it is widely adopted by PLC and RTU manufacturers. The Modbus communication method adopts a master-slave query corresponding mechanism. Only when the master station sends a…
Converting 0-10VDC to 4-20mA for Robust Signal Transmission in Water Supply Systems
In variable frequency water supply control systems, remote pressure gauges play a crucial role in monitoring and maintaining consistent pressure levels. These gauges often exhibit resistance values ranging from 100 to 500 ohms, which correspond to a continuous pressure range, such as 0-10 MPa. Traditionally, this variable resistance can be utilized by series connecting a larger resistor and applying a…
Analysis of Zero Position Adjustment for Incremental Optoelectronic Encoder for Initial Position Detection of Permanent Magnet Synchronous Motor Rotors
The mainstream servo motor position feedback components include incremental encoders, absolute encoders, rotary transformers, etc. The vector control of permanent magnet AC servo drive requires a position feedback component to provide the position information of the rotor D-axis of the permanent magnet motor to the servo driver. After the position feedback component is installed with the motor, it is necessary…
Abb Acs580 Fault Code 7122,What does this fault code mean and how can it be reset?
The ACS580 stands as an upgraded iteration compared to the previous ABB ACS550 inverter, boasting enhanced functionalities like vector control. Its versatile applications cover a wide range. Internally, the ACS580 exhibits a distinct circuit structure from its predecessor, the ACS550. In the course of ACS580 usage, encountering various faults and alarm scenarios is common. However, the fault codes and alarms…