Danfoss VLT HVAC Drive FC 102 Operating Manual page 143

Operating Guide | VLT® HVAC Drive FC 102
9.3.44 ALARM 46, Power Card Supply
Cause
The supply on the power card is out of range. Another reason can be a defective heat sink fan.
There are 3 supplies generated by the switch mode supply (SMPS) on the power card:
• 24 V.
• 5 V.
• ±18 V.
®
When powered with VLT 24 V DC Supply MCB 107, only 24 V and 5 V supplies are monitored. When powered with 3-phase mains
voltage, all 3 supplies are monitored.
Troubleshooting
• Check for a defective power card.
• Check for a defective control card.
• Check for a defective option card.
• If a 24 V DC supply is used, verify proper supply power.
• Check for a defective heat sink fan.
9.3.45 WARNING 47, 24 V Supply Low
Cause
The supply on the power card is out of range.
There are 3 supplies generated by the switch mode supply (SMPS) on the power card:
• 24 V
• 5 V
• ±18 V
Troubleshooting
• Check for a defective power card.
9.3.46 WARNING 48, 1.8 V Supply Low
Cause
The 1.8 V DC supply used on the control card is outside of the allowed limits. The supply is measured on the control card.
Troubleshooting
• Check for a defective control card.
• If an option card is present, check for overvoltage.
Danfoss A/S © 2018.10
Maintenance, Diagnostics, and
Troubleshooting
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