Danfoss VLT HVAC Drive FC100 Service Manual page 3

Contents
2.8 Earthing Screened Cables
3 Internal Frequency Converter Operation
3.1 General
3.2 Description of Operation
3.2.1 Logic Section
3.2.2 Logic to Power Interface
3.2.3 Power Section
3.3 Sequence of Operation
3.3.1 Rectifier and Option Cabinet
3.3.2 Intermediate Section
3.3.3 Inverter Section
3.3.4 Brake Option
3.3.5 Cooling Fans
3.3.6 Fan Speed Control
3.3.7 Load Sharing
3.3.8 Specific Card Connections
4 Troubleshooting
4.1 Troubleshooting Tips
4.2 Exterior Fault Troubleshooting
4.3 Fault Symptom Troubleshooting
4.4 Visual Inspection
4.5 Fault Symptoms
4.5.1 No Display
4.5.2 Intermittent Display
4.5.3 Motor Will not Run
4.5.4 Incorrect Motor Operation
4.6 Alarms and Warnings
4.7 Warning and Alarm Definitions
4.8 After Repair Tests
5 Frequency Converter and Motor Applications
5.1 Torque Limit, Current Limit, and Unstable Motor Operation
5.1.1 Overvoltage Trips
5.1.2 Mains Phase Loss Trips
5.1.3 Control Logic Problems
5.1.4 Programming Problems
5.1.5 Motor/Load Problems
5.2 Internal Frequency Converter Problems
5.2.1 Overtemperature Faults
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High Power Service Manual for Modular F Frame Drives
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MG90K202 - VLT is a registered Danfoss trademark
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