F514 fault in ABB DCS880 drive indicates Mains synchronization lost. This means the synchronization with the mains has been lost.

1. Check the condition of the mains (voltage, cabling, fuses, switchgear).
2. Check the mains frequency (50 Hz ±5 Hz; 60 Hz ±5 Hz) and stability (df/dt = 17 %/s) see 95.39 PLL input deviation and 95.40 PLL output, internal mains frequency.