Veichi AC310, Руководство по обслуживанию

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AC310 Universal AC Drive Service Manual
16
2.4 Busbar Voltage Detection Circuit
1. Circuit composition
The bus voltage sampling circuit is a high-resistance isolation circuit that utilizes multiple
resistors in series for isolation and then differential amplification by operational amplifiers.
2. Fault type
Inaccurate bus voltage display, overvoltage, undervoltage
3. Inspection methods
Static detection
If the VPN voltage value is incorrect during the test (dynamic detection has a
measurement method), please test the following parts
(i) Op-amp U75=LF353DRG4; (ii) Test the voltage divider resistor; (iii) Diodes D70 and
D71 to replace the damaged devices, and then test the
VPN voltage point to ensure that the detection value is correct.
Dynamic detection