Symptom
Grid overvoltage
- ID
symptom:grid-overvoltage- IRI
https://solarlattice.org/kb/symptom/grid-overvoltage- Status
- active
- Also known as
- AC overvoltage, Over Grid Voltage, OV-G-V, 10-minute grid overvoltage, Grid transient overvoltage, Grid Uncompliant
Grid overvoltage means the inverter measures AC voltage above its protection setpoint and disconnects from the grid. It normally reconnects once the grid is back to normal. In monitoring data it often repeats as a cycle: the inverter trips, voltage drops, the inverter reconnects after the set delay, and voltage climbs until the next trip, which may come seconds or minutes later. Some inverters report a separate fault when the ten-minute average voltage stays too high, and another for short transient overvoltage spikes. The cause can be a weak grid, where high distribution-grid resistance meets a lot of local PV capacity. It can also be local, from AC cables between the inverter and the grid connection that are too small or too resistive. Check first: with the DC switch off, measure AC voltage at the inverter. If it is already high, the grid is the cause and the utility should be contacted. If voltage is only high at full power, compare the inverter display with your test-point readings and review the cable ampacity, voltage-drop calculation and cable cross-section. Also confirm that the overvoltage protection parameters are set correctly. Change them only with the utility operator's consent.
<!-- review notes
- sentence 1: support check: partial - Passages say the inverter reconnects after the grid returns to normal and the voltage exceeds the set protection value, but disconnection is only implied by reconnection and the 10-minute fault says to wait for normal.
- sentence 2: support check: partial - The cycle is described, but the passage doesn't say it appears in monitoring data or that it often repeats, and it states the cycle only as a possibility.
- sentence 5: support check: partial - Passage says to switch DC off, check AC at the inverter, and adjust the upper limit with utility permission if it is high; it doesn't state that the grid is the cause, though it says to contact the utility.
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Claims
observed_as
c1 verified · fact
Grid voltage outside limits
The inverter or storage unit sees AC grid voltage above its protection setpoint and disconnects. It usually reconnects once the grid returns to normal.
verified by: review-workflowverified on: 2026-10-20review note: support check: partial - Passages show grid overvoltage faults where voltage exceeds the set protection value and the inverter reconnects after normalization, but the specific signal behaviors (power falling to zero while disconnected, voltage rising before the trip) are not stated.
c2 drafted · lead
Ten-minute average overvoltage
The ten-minute average of grid voltage stays above the permitted range, which points to grid voltage or grid impedance at the connection point being too high.
c3 drafted · lead
Repeated trip-reconnect cycling
The inverter disconnects, voltage falls, it reconnects after the reconnection delay, and voltage climbs again. The next trip can follow after seconds, minutes or longer as the wires heat up again.
c4 drafted · lead
Transient grid overvoltage event
A short voltage spike above the standard value, reported under a separate fault code from sustained overvoltage.
c5 drafted · lead
Volt-watt power derating
With volt-watt derating set up, active power is reduced as grid voltage rises between a start voltage and an end voltage. These voltages are configurable settings.
review note: support check: partial - The derating table gives the V1 start and V2 end voltage settings, which are configurable, but it does not explicitly state that power is reduced between them (only start/end power points) or describe the monitoring signals.
Referenced by
Data