Cause : Mains not in synchronism comes when the synchronization with the mains frequency has been lost. This situation can occur during start-up or when the drive attempts to synchronize with the mains power, and it may lead to operational issues if not addressed promptly.

F514 Mains not in synchronism fault in ABB DCS800 drive indicates a mains not in synchronism condition. This means that the voltage supplied to the drive from the power grid is not synchronized with the drive's internal voltage.

Here’s how to troubleshoot and resolve this fault:

1. Check Power Supply Frequency:

• Verify the frequency of the incoming mains supply using a frequency meter or oscilloscope. Ensure it is stable and within the specified range (typically around 50 or 60 Hz, depending on your region).
• Look for fluctuations or irregularities in the mains frequency that could cause synchronization issues.

2. Inspect the Drive’s Configuration:

• Review the drive settings related to synchronization and reference frequency. Ensure that the parameters are correctly set to match the mains supply specifications.
• Confirm that the motor type and characteristics (like rated frequency and speed) are correctly configured in the drive.

3. Check for External Influences:

• Investigate if any equipment connected to the mains supply is causing disturbances, such as large inductive loads that may affect frequency stability.
• Consider potential voltage or frequency fluctuations from upstream sources, especially if the supply comes from a generator or transformer.

4. Monitor for Electrical Issues:

• Inspect for loose or corroded connections in the power supply circuit. Poor connections can cause voltage drops or frequency variations.
• Check for phase imbalances, which can impact synchronization. All three phases should be balanced and functioning correctly.

5. Examine the Start-Up Process:

• If the fault occurs during start-up, ensure that the drive is set up to handle the motor's characteristics during this phase. Adjust any soft-start settings or acceleration ramps as needed to ensure a smoother synchronization process.