> ## Documentation Index
> Fetch the complete documentation index at: https://fop-50527c4b.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Using Inverter Logs for Legal and Insurance Claims

> Use SUN2000 inverter logs as tamper-proof evidence for grid overvoltage claims, power curtailment compensation, warranty disputes, and access audits.

Inverter logs function as a flight recorder for your solar installation. The Huawei SUN2000 writes timestamped records of every grid abnormality, every forced curtailment command, every protection event, and every user login to non-volatile memory that cannot be altered after the fact. When a dispute arises — whether with the grid operator, an insurer, or a maintenance contractor — these logs provide the kind of precise, time-stamped evidence that verbal accounts and manual site inspection reports cannot match.

## Grid overvoltage claims

When the grid voltage rises above the inverter's configured protection threshold (typically 253 V on a 230 V nominal grid), the inverter disconnects automatically to protect itself and complies with grid code requirements. Each such event is recorded in `alarmg_history` with the exact timestamp of the onset and the time of recovery.

If your plant experiences frequent "Grid Overvoltage" alarms, export `alarmg_history` and count the events over a representative period — a few months is usually sufficient to demonstrate a pattern. Present this report to your grid operator as evidence that the local distribution transformer or line is consistently operating out of specification. A documented history of hundreds of such events is difficult to dispute and provides the factual basis to demand infrastructure upgrades: transformer tap adjustment, line reinforcement, or reactive power compensation equipment.

## Power curtailment compensation

When a grid dispatcher issues a forced generation limit through a SmartLogger, the command and its effect are recorded in `grid_adj_log`. This log captures the exact time the curtailment started, the level to which generation was reduced, and when the limit was lifted. Using the generation data from `perfmg_data` alongside `grid_adj_log`, you can calculate the precise kWh you were prevented from generating and apply your feed-in tariff or PPA rate to arrive at the lost revenue figure for a compensation claim.

<Note>
  `grid_adj_log` is only available on sites equipped with a SmartLogger. On sites connected exclusively via SDongle, this log is not generated. As an alternative, use register **32080** (Active Power) from the `his_inv_rd` archive: compare the recorded power output during the curtailment window against the expected output based on irradiance data from the same period.
</Note>

<Tip>
  Export your logs within 30 to 90 days of any incident. The SUN2000 uses a circular buffer (FIFO) in its internal flash memory. Once the buffer fills, the oldest records are overwritten by new data. Logs older than 30 to 90 days — depending on the inverter model and logging frequency — may no longer be recoverable.
</Tip>

## Warranty claims

When an inverter component fails, the key question for a warranty claim is whether the failure was caused by an internal defect or by an external event such as a lightning surge. The `dsp_wave_data` log records the oscillographic waveform of voltage and current at millisecond resolution in the moments immediately before a protection event triggers.

An internal defect typically produces a clean fault signature with no preceding voltage spike. An external lightning surge or switching transient leaves a clearly visible impulse on the waveform before the failure. Present `dsp_wave_data` to the Huawei service team or your insurer alongside the fault record from `alarmg_history`: together, they establish the cause of failure with a level of precision that no post-event inspection can provide.

## Unauthorized access disputes

The `usrmg_usrlog_2` log records every login to the inverter's management interface: the username, the timestamp, and the interface used (for example, Bluetooth via the FusionSolar app). This log resolves a common dispute in O\&M: did the inverter shut down due to an internal fault, or did a service technician issue a manual shutdown command?

If a contractor denies having issued a command, or if a plant owner suspects that settings were changed without authorization during a site visit, `usrmg_usrlog_2` provides a verifiable record. Combined with `alarmg_history` and `cfg_file_ctrl` (which records configuration changes), you can establish exactly who accessed the inverter, when, and whether any settings were modified.