Sunway NT 2600, NT 6000, NT 4000 user manual Fault display Causes, UAC3

Fault display Causes Remedies

UAC_1	The grid voltage is too low
UAC_3	or too high.
AC under/over-
voltage

The solar inverter monitors the limits of the minimum and maximum permissible

3-phase grid voltage. If the values exceed or fall below these limits (Umin = 184 V, Umax = 264 V), the solar inverter swit- ches off and only restarts automatically when the voltage value has returned within the limits. The fault cut-out can be triggered even if the values only exceed or fall below the limits very briefly (up to ca. 1 ms).

Ask your electricity board about grid stability and design.

The cable cross-section in the AC feed line to the solar inverter is too small.

Your solar system feeds into a spur line, which is inade- quately dimensioned.

Check the format of your grid connection (energy counter) and the grid feed-in point to your electricity board.

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