EL
ErrorLib
Brands
||
  1. Home
  2. Danfoss
  3. VLT HVAC Basic FC 101
  4. ALARM 52
About·Privacy·Terms

ErrorLib — Industrial Fault Code Library

Disclaimer: ErrorLib is an independent technical reference tool. While we aim for accuracy, always verify with the manufacturer’s official service manuals before performing maintenance on industrial equipment. ErrorLib is not affiliated with the brands listed.

ALARM 52

AMA low Inom

Danfoss · VLT HVAC Basic FC 101

What does ALARM 52 mean?

The motor current detected during the Automatic Motor Adaptation (AMA) process is too low. This usually indicates an incorrect motor current setting in the parameters or an issue with the motor connection itself, hindering proper parameter identification.

Common Causes

  • Motor nominal current (P1-21) set too high in parameters relative to the actual motor nameplate current.
  • Open phase or high resistance connection in one or more motor phases (U, V, W) at the drive or motor side.
  • Internal short circuit or winding damage within the motor, causing reduced current draw or imbalance.
  • Incorrect motor sizing (motor is too small) for the frequency converter's minimum current sensing range.
  • Output current measurement circuit fault within the frequency converter itself.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Verify the motor nominal current (P1-21) matches the motor nameplate data accurately.

  2. 2

    Measure the resistance between motor phases U-V, V-W, W-U at the motor terminals; they should be balanced.

  3. 3

    Check all motor output terminals (U, V, W) for loose connections, corrosion, or damaged wiring.

  4. 4

    Perform an insulation resistance test (Megger test) on the motor windings to ground and phase-to-phase.

  5. 5

    If accessible, measure the motor phase currents (on U, V, W) during a basic V/Hz run to observe current draw.

Browse all codes in this manual (40)
Verified technical data. Last updated: April 2026

Related Faults

10Motor overload temperature11Motor thermistor overtemperature13Overcurrent
Source: Danfoss VLT HVAC Basic FC 101
View Official PDFSearch more codes in this manual