East EA990G5, Руководство по обслуживанию

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Step 5: Use the diode gear of the multimeter to test the input rectifier diode and Boost diode. If the forward
voltage drop is too low (less than 0.1V) or there is also a reverse voltage drop, the diode may be damaged and
needs to be replaced.
Step 6: Measure the resistance of the battery thyristor (SCR) with a multimeter in the ohm range. The normal
resistance should be around 20Ω. If not, it needs to be replaced.
After completing the inspection work in steps 1-6, replace the damaged device; after replacing the device,
use the shorting cap to short-circuit J2 of the rectifier control board CT1 and J2 of the inverter control board CT2,
and then follow the steps shown in Figure 6-4. Connection method Connect the main power board to the input and
output board (only connect the signal cable, not the copper bus), and carry out the drive test. The test waveforms
of each key device are shown in Table 6-4.
Fig.6-4 The connection of drive test circuit of 15kVA power board
Table 6-4 The driver test description of 15kVA power board
Component and its tag number Waveform Remark
Boost IGBT
Q1,Q2,Q3,Q4,Q5,Q6
High level
+15V±1V
；
Low level
-8V±1V
；
Frequency
40KHz
；