Danfoss VLT HVAC FC 100, Service Manual, Page: 3 / 220

Cooling Fans 3-12
Fan Speed Control 3-12
Load Sharing 3-13
Specific Card Connections 3-14
4 Troubleshooting
4-1
Troubleshooting Tips 4-1
Exterior Fault Troubleshooting 4-1
Fault Symptom Troubleshooting 4-2
Visual Inspection 4-3
Fault Symptoms 4-4
No Display 4-4
Intermittent Display 4-4
Motor Will not Run 4-5
Incorrect Motor Operation 4-6
Warning/Alarm Messages 4-7
Warning/Alarm Code List 4-7
After Repair Tests 4-21
5 Adjustable Frequency Drive and Motor Applications
5-1
Torque Limit, Current Limit, and Unstable Motor Operation 5-1
Overvoltage Trips 5-2
Line Phase Loss Trips 5-3
Control Logic Problems 5-3
Programming Problems 5-4
Motor/Load Problems 5-5
Internal Adjustable Frequency Drive Problems 5-5
Overtemperature Faults 5-5
Current Sensor Faults 5-6
Signal and Power Wiring Considerations for Adjustable Frequency Drive
Electromagnetic Compatibility
5-6
Effect of EMI 5-7
Sources of EMI 5-7
EMI Propagation 5-8
Preventive Measures 5-9
Proper EMC Installation 5-11
6 Test Procedures
6-1
Introduction 6-1
Contents
High Power Service Manual for VLT
®
FC Series
Adjustable Frequency Drives
MG.90.L1.22 - VLT ® is a registered Danfoss trademark