Mitsubishi inverter fault handling - Solutions - Huaqiang Electronic Network

Photocoupler

In the domestic market, Mitsubishi has a fairly broad market due to its stable quality and strong brand influence, and has penetrated into various fields of application.
1. OC1, OC3 failure In the past, the author introduced Mitsubishi inverter OC (overcurrent fault) many times will be caused by the following reasons (now A500 series inverter as an example).
(1) caused by improper parameter setting, such as the time setting is too short;
(2) caused by external factors, such as motor winding short circuit, including (phase-to-phase short circuit, short circuit to ground, etc.);
(3) Inverter hardware failure, such as Hall sensor damage, IGBT module damage, etc.
2. UVT fault UVT is an undervoltage fault. It is believed that many customers will still encounter such problems during use. Our common undervoltage detection points are the voltage on the DC bus side. After a large resistance resistor, the voltage is sampled low. The voltage value is compared with the standard voltage value to output a voltage normal signal, an overvoltage signal or an undervoltage signal. The sampling value of the voltage signal of Mitsubishi A500 series inverter is obtained from the switching power supply side and is isolated by the optocoupler. During our maintenance process, it is found that the damage of the optocoupler occupies very much in the cause of the undervoltage fault. The large proportion, this phenomenon is still rare in the previous inverter repair.
3. E6, E7 fault E6, E7 fault is no stranger to the majority of users, this is a relatively common Mitsubishi inverter typical fault, of course, the cause of damage is also multifaceted.
(1) The integrated circuit 1302H02 is damaged. This is an IC integrated circuit that integrates drive waveform conversion and multi-channel detection signals, and has multiple signals associated with the CPU board. In many cases, any one of the signals of this integrated circuit may cause E6. , E7 alarm;
(2) The signal isolation optocoupler is damaged. There are multiple strong and weak signals between the IC integrated circuit 1302H02 and the CPU board that need to be isolated. The damage of the isolated optocoupler is relatively high in the damage ratio of the components. Therefore, in the case of E6 and E7 alarms, it should also be considered. Whether it is caused by such factors;
4. Switching power supply damage Switching power supply damage is also a common fault of A500 series inverters. We often mention that the pulse transformer is damaged, the switch FET is damaged, and the starting resistance is damaged.
5. Power module damage The power module is damaged, mainly in the E500 series inverter. For the low-power inverter, because it is an intelligent module that integrates the power device and the detection circuit, it can only be replaced when the module is damaged, but the maintenance cost is high and there is no maintenance value. For the 5.5KW, 7.5KW E500 series inverter, the PIM power module of 7MBR series is selected, the replacement cost is relatively low, and some damage can be done for the damage of such inverter.