Danfoss VLT AAF006 - Page 3

3 Internal Active Filter Operation
3-1
3.1 General
3-1
3.2.2 Control Card 3-1
3.2.3 Active Filter Card 3-2
3.2.4 Control to Power Interface 3-2
3.2.5 Filter Power Section 3-3
3.3 Additional Circuitry
3-3
3.3.1 AC Contactor 3-3
3.3.2 Soft Charge Circuit 3-3
3.3.3 Additional Thermal Protection 3-4
3.3.4 Current Transducers 3-4
3.3.5 Cooling Fans 3-4
3.3.6 Fan Speed Control 3-4
3.3.7 Low Harmonic Drive 3-5
4 Troubleshooting
4-1
4.1 Troubleshooting Tips
4-1
4.2 Fault Symptom Troubleshooting
4-1
4.3 Visual Inspection
4-2
4.4 Fault Symptoms
4-3
4.4.1 No Display 4-3
4.4.2 Intermittent Display 4-3
4.5 Warning/Alarm Messages
4-4
4.5.1 Warning/Alarm Code List 4-4
4.6 After Repair Tests
4-12
5 Active Filter and the Power Grid
5-1
5.1 Grid Variations
5-1
5.1.1 Grid Configurations 5-1
5.1.2 Grid Impedance 5-1
5.1.3 Voltage Pre-distortions 5-1
5.2 Basic Troubleshooting Background
5-1
5.2.1 Line Phase Loss and Unbalanced Phase Trips 5-1
5.2.2 Voltage Dips and Flickers 5-1
5.2.3 Compatibility with Other Equipment on the Same Line Power 5-2
5.2.4 Line Power Resonances 5-2
5.2.5 Control Logic Problems 5-2
5.2.6 Programming Problems 5-3
Contents VLT Advanced Active Filter AAF006 D and E Frames Service Manual
MG90Z122 - VLT
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