52

AMA: Motor current too low

Danfoss · VLT HVAC Drive High Power

What does 52 mean?

The motor current parameter (parameter 1-24) entered for the Automatic Motor Adaptation (AMA) is set too low for the connected motor. This incorrect setting can lead to inaccurate motor modeling during AMA, resulting in suboptimal drive control and potential misoperation or reduced performance.

Common Causes

  • Motor nominal current (P1-24) is set significantly below the actual motor nameplate FLA.
  • Drive internal current sensing error or calibration issue.
  • Partial motor winding short or open circuit, leading to reduced current draw.
  • Motor parameters (e.g., P1-20, P1-22) are inconsistent with the low current setting.
  • Incorrect motor type selection (e.g., induction motor parameters used for a PM motor).

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    1. Increase Parameter P1-24 (Motor Current) to precisely match the motor nameplate FLA.

  2. 2

    2. Verify motor winding resistance across all three phases (U-V, V-W, W-U) using an ohmmeter (readings should be balanced within 5%).

  3. 3

    3. Check for secure connections at the motor terminal block and drive output terminals (U, V, W).

  4. 4

    4. Measure actual motor current with a clamp meter during a light load test run (if possible) and compare to drive's current display.

  5. 5

    5. If problem persists after correcting P1-24, consider performing a drive factory reset and re-entering all parameters.

Browse all codes in this manual (60)
Verified technical data. Last updated: March 2026

Related Faults

Source: Danfoss VLT HVAC Drive High Power