Fuji elevator special inverter faults and repairs - Solutions - Huaqiang

Filter 18.432M

L0504-Murata muRata common mode inductor 90Ω 150mA

The fault shows OC1, OC2, OC3, which is one of the most common faults of Fuji elevator-specific inverters. It includes over-current in inverter acceleration, over-current in deceleration, and over-current in constant speed. There are mainly the following:

(1) The acceleration time is too short, which is the most common in our overcurrent phenomenon. According to different load conditions, we can adjust the acceleration/deceleration time accordingly to eliminate this fault.

(2) Damage to high-power transistors may also cause OC alarms. The high-power transistors of Fuji Elevator-specific inverters have undergone several replacements with the development of semiconductor technology, from the early use of G2 (P2), G5 (P5), The GTR module of the G7 (P7) series, the IGBT module of the G9 (P9) series, and the IPM module used until now, both the packaging technology and the protection performance, have greatly improved, high withstand voltage, high current, high Frequency, low power, quiet, and multi-protection functions have become the development trend of high-power transistor modules. The damage of the high power transistor module may be caused by the following reasons:

a) The output load is short-circuited;

b) the load is too large and a large current continues to appear;

c) The load fluctuates greatly, resulting in excessive surge current, which may cause OC alarm and damage the power module.

(3) Damage to the drive circuit that drives the operation of high-power transistors is also a cause of overcurrent alarms. Fuji G7S and G9S use PC922 and PC923 as the core parts of the drive circuit respectively. Due to the built-in amplifier circuit, the circuit design is simple, and it is widely used by many inverter manufacturers including Fuji elevator special inverter. The most common phenomenon exhibited by the damage of the drive circuit is the lack of phase, or the three-phase output voltage is unbalanced.

(4) The damage of the detection circuit will also cause the inverter to display the OC alarm. The Hall sensor that detects the current is affected by environmental factors such as temperature and humidity, and the operating point is prone to drift, resulting in OC alarm.

·Switching power supply is damaged

One of the more obvious features of switching power supply damage is that the inverter does not display power. The Fuji G5S uses a two-stage switching power supply. It first converts the DC voltage of the intermediate DC circuit from more than 500 V to more than 300 V, and then passes the primary switch. Power output 5V, 24V and other multi-channel power supply, switching power supply damage is common with switch tube breakdown, pulse transformer burnout, and secondary output rectification diode damage, filter capacitor use time is too long, resulting in changes in capacitance characteristics, loading The ability to drop is also very likely to cause damage to the switching power supply. Fuji G9S uses a waveform-generating chip dedicated to switching power supplies. Due to the high voltage of the main circuit, it often causes damage to the chip. Since this chip market is rarely available, the damage is more difficult to repair.

·Rectifier bridge damage

The damage of the rectifier bridge is also a common fault of the Fuji elevator special inverter. The Fuji G7S uses a rectifier module with a thyristor. The difference between it and the ordinary rectifier bridge is that it replaces the main loop contactor with a thyristor. The reliability of the machine. G9S low power machine rectifier bridge is integrated with thyristor and switch tube. The damage of the rectifier bridge is often closely related to the external power supply of the machine. When the rectifier bridge fails, we can no longer blindly power on the power supply. The peripheral equipment should be checked first.

· LV, OV

Undervoltage and overvoltage are also common faults of Fuji elevator-specific inverters. This has the possibility of fault alarm caused by main power factor, and the possibility of alarm caused by damage to the machine detection circuit. Fuji G5S uses a customized voltage detection thick film phone. To detect the DC voltage of the main circuit, the G7S and G9S are directly sampled and detected from the DC main circuit, and the detection effect is the same.