Problem 1: When the GRID mode is good, whe the light indicate, the buzzer beeping, and the UPS power supply can only work in the converte mode and cannot turn to the grid mode
Analysis: Cannot turn to the Grid mode Malfunction
1. Check Grid input fuse;
2 .Check output of the grid rectifier filter
3. Check the grid detection part;
4 .Check the output of the inverter power supply to the Grid supply conversion control
Problem 2: When a backup UPS in Grid mode output voltage is low, and the transformer Cause loud noise.
Analysis: The output of the inverter indicates that the final drive circuit is basically normal. The noise of the transformer indicates that the two arms of the push-pull circuit are asymmetrical. The detection steps are as follows:
1. Check if the power is normal;
2. Check the output signal of the pulse width output
3. Check if the output of the drive circuit
Problem 3: The UPS power supply can only work on Grid mode power supply
Analysis: conversion malfunction
1. Whether the battery voltage too low, battery fuse;
2. Battery voltage detection circuit
3. Check whether the utility power supply to the inverter power supply conversion output
Problem 4: Backup UPS power supply When reach full load, the grid supply is good, But the battery fuse turn on.
Analysis: The problem is the battery supply current too large. The detection steps are as follows:
1. Whether the inverter is broken down;
2. Whether the battery voltage too low;
3. If the battery voltage is too low, check if the battery charging
4. If the battery charging circuit okay, check the battery voltage detecting
