Infeed: Line supply undervoltage alarm

What does 206105 mean?

An alarm indicating that the filtered, steady-state value of the line supply voltage has dropped below the alarm threshold set by p0282. This is a warning condition, not a shutdown, meaning there is no immediate reaction. The alarm value (r2124) shows the current line supply voltage.

• Moderate voltage sag on the incoming AC line supply, not severe enough for shutdown but indicating instability (e.g., network fluctuations, temporary load spikes).
• Undervoltage alarm threshold parameter P0282 (DC link voltage alarm threshold) is set too high, triggering alarms for minor deviations.
• Degraded power factor correction capacitors in the facility, causing larger voltage drops under load.
• Long power cables or undersized conductors from the main distribution panel to the machine, leading to voltage drop under load.

Click steps to track your progress.

1. 1

   1. Measure the incoming AC line supply voltage (L1-L2, L2-L3, L3-L1) at the infeed power terminals using a power quality analyzer to log voltage variations over time.

2. 2

   2. Review parameter P0282 (DC link voltage alarm threshold) and compare it to the system's nominal voltage and acceptable operating range. Adjust if set too aggressively.

3. 3

   3. Inspect power cabling from the main distribution to the machine for correct sizing (gauge) and secure connections, checking for signs of overheating.

4. 4

   4. Monitor the actual DC link voltage (r0026) during machine operation, noting the specific values when the alarm is triggered.

5. 5

   5. Consult with facility management to investigate broader electrical network stability and consider installing a voltage stabilizer if fluctuations are frequent.