> ## Documentation Index
> Fetch the complete documentation index at: https://learning.kent.co.in/llms.txt
> Use this file to discover all available pages before exploring further.

# Grid Fault Alarms: Voltage, Frequency, and No-Grid Events

> Grid voltage and frequency alarms on Kent M1 and G3 — separating a weak grid from a bad connection, alarm name differences, and the utility-consent rule.

Your goal is to determine whether the inverter's grid protection is responding to a real grid issue or to a problem in the connection between the grid and the inverter's terminals.

**Symptom:** grid-class alarms appear — over/under-voltage, over/under-frequency, or no-grid — either once in a storm or every afternoon like clockwork.

<Warning>
  **Grid protection points are not a tuning knob.** They move only with utility consent and Kent instruction — never to silence a nuisance trip. On the Kent G3, protection levels load automatically from the selected grid code; do not hand-edit individual protection values.
</Warning>

## Check first

1. **Occasional or chronic?** A one-off alarm during a known grid disturbance self-clears by design — no action needed. A daily or hourly pattern requires measurement data before any action.
2. **Measure at the inverter's AC terminals across the problem window** — the terminal voltage, not the DB board voltage, is what the inverter sees. One hour of readings across the problem period tells you far more than a single spot measurement.
3. **Terminations tight?** Loose or undersized AC terminations mimic an out-of-band grid at every load step. Check these before concluding the grid is the problem.

## Causes

| Cause                                       | How to confirm                                                                      | Fix                                                                                                                         |
| ------------------------------------------- | ----------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------- |
| Genuine grid excursion (transient)          | Alarm self-clears; terminal voltage is normal when measured                         | None needed — the inverter reconnects automatically when the grid returns to the acceptable range                           |
| Chronically out-of-band grid                | Logged terminal readings are out of the code's window at peak hours                 | DISCOM case: Kent compiles the evidence and leads the utility-consent process; do not adjust protection values unilaterally |
| Loose or undersized AC connection           | Voltage sags at the inverter terminals under load steps; heat marks at terminations | Re-terminate and torque per the platform AC wiring page; re-measure across a full day                                       |
| Wrong grid code selected                    | Commissioning record vs the Kent parameter sheet for the site's DISCOM              | Set the grid code from the Kent parameter sheet only                                                                        |
| No grid detected                            | Kent M1: **E100** · Kent G3: **NO-Grid**; upstream breaker off or phase dead        | Restore the AC path — follow [Not Starting](/troubleshooting/not-starting)                                                  |
| Unbalanced or distorted grid (Kent G3 only) | **G-PHASE / GRID-INTF02** class alarms appear alongside measurements                | Confirm the grid quality and the AC cable run; one restart; if persistent, escalate                                         |

<Note>
  **Alarm names differ between platforms.** Kent M1 uses **E101** (grid voltage) / **E102** (grid frequency) / **E108** (other grid abnormalities). Kent G3 uses the **OV-G-V / UN-G-V / OV-G-F / UN-G-F** alarm families. The triage is the same — record the exact alarm string, letter-for-letter, before doing anything else.
</Note>

<Warning>
  **Pending Kent validation — do not configure in the field.** \[KNB-VAL-01]
  The India grid-code parameter set for both platforms — voltage and frequency windows, reconnect timing, power factor — is under confirmation. Until published here: set the grid code only from the Kent-issued parameter sheet for the site's DISCOM. Never improvise protection values.
</Warning>

## Escalate when

* The grid is chronically out of band on logged terminal measurements — Kent leads the DISCOM process; bring the readings, timestamps, and photos.
* Grid alarms persist on a site with a verified-healthy grid and tight terminations — this is a service case.
* Any request arrives to "just widen the limits" — that path runs through utility consent and Kent, or it does not happen.

<Note>
  **Escalate to Kent New Energy service only** — through your registered Kent partner channel or the Kent service desk details on your work order. Do not contact any third-party or component-manufacturer support line for a Kent-branded system: tickets outside the Kent channel are not tracked, not covered, and can void warranty handling.
</Note>

## Related pages

* [Not Starting](/troubleshooting/not-starting)
* [Kent M1 AC Wiring](/m1/ac-wiring)
* [Kent G3 AC Wiring](/g3/ac-wiring)
* [When to Escalate](/troubleshooting/when-to-escalate)