Danfoss VLT HVAC Drive FC 102
Danfoss VLT HVAC Drive FC 102 code 51: AMA check Unom and Inom
The automatic motor adaptation fails because the programmed settings for motor voltage, current, and power are incorrect.
- Code
- 51
- Name
- AMA check Unom and Inom
- Controller
- Danfoss VLT HVAC Drive FC 102
- Type
- Setup or parameter fault
- What it does
- Fault: the equipment trips and stops
- Risk
- YELLOW Booth plays by its own rules
- Source
- The manufacturer's manual (subscribers see which manual and page)
Updated November 4, 2026
How to fix it
Subscribers get:
- What to do next, in plain words
- What the manual says to do, and the page it is on
- The 1 common cause listed for this code
- Booking a live video call with Ben, a master booth technician ($250/hr, paid per call)
Questions about this code
What does Danfoss VLT HVAC Drive FC 102 code 51 mean?
The automatic motor adaptation fails because the programmed settings for motor voltage, current, and power are incorrect.
Is Danfoss VLT HVAC Drive FC 102 code 51 dangerous?
It is graded yellow: not hard, but a booth does it differently than the gear most techs know, so follow the checks in order.
How do I fix Danfoss VLT HVAC Drive FC 102 code 51?
The manual's fix and the step by step check for this code are in WERCS Diagnose, plans from $49 a month. For help right now, WERCS answers 24/7 at (877) 489-3727.
Other Danfoss VLT HVAC Drive FC 102 codes
47 · 24 V supply low48 · 1.8 V supply low49 · Speed limit50 · AMA calibration failed52 · AMA low Inom53 · AMA motor too big54 · AMA motor too small55 · AMA parameter out of range56 · AMA interrupted by user57 · AMA internal fault
All 73 Danfoss VLT HVAC Drive FC 102 codes · Every fault code