> ## 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.

# Zero Export Explained: Control Loop and Setting Stacks

> What zero-export limiting actually does, why brief blips are physics not faults, the per-platform setting stacks, and what the function cannot guarantee.

Zero export is a control loop, not a physical wall. Understanding what it actually does — and what it cannot promise — prevents the most common compliance conversations with DISCOMs and customers. Always witness it live before signing off a limited site.

<Warning>
  **For trained and authorised installers only.** Export settings live behind partner-gated menus and carry compliance consequences. Do not configure these settings without the correct access level.
</Warning>

## What zero export actually does

The CT or meter at the grid connection reports any export to the inverter. The inverter responds by throttling PV output and steering surplus into the battery to hold export at the configured limit. When the limit is set to zero, the goal is zero sustained feed-in — but some physics apply:

* **Brief export blips on sudden load drops are normal.** The loop measures, then reacts — there is always a short lag. A battery absorbing surplus is what turns those blips into near-zero behaviour in practice.
* The loop only sees what the CT sees. Every zero-export investigation starts at [Direction & Location](/ct-meter/direction-and-location) — a reversed or misplaced CT makes the loop chase the wrong number.

## The two setting stacks — work from your platform's page only

Parameter names differ completely between platforms. Using settings from the wrong platform's guide is one of the most common commissioning errors.

### Kent M1

| Setting            | Purpose                                                               |
| ------------------ | --------------------------------------------------------------------- |
| **Solar Sell**     | Set to **OFF** for zero-export intent                                 |
| **Max sell power** | Caps feed-in; requires a meter or CT connected                        |
| **Sell offset**    | Compensates metering error — prevents anti-backflow from over-selling |

An anti-backflow breach detected on the Kent M1 raises **E105** on the LCD.

<Warning>
  **Pending Kent validation — witness test mandatory.** \[KNB-VAL-07] The exact zero-feed behaviour of Kent M1 "Max sell power = 0" is under bench confirmation. Until published here: every export-limited Kent M1 site requires the [zero-export witness test](/ct-meter/energy-flow-test) before sign-off. Configuring the settings is not sufficient on its own.
</Warning>

Full parameter table: Kent M1 Settings Reference.

### Kent G3

| Setting                | Purpose                                                                               |
| ---------------------- | ------------------------------------------------------------------------------------- |
| **Allow Export**       | Set to **OFF** where feed-in is not permitted                                         |
| **Max export power**   | Set to **0** when Allow Export is OFF                                                 |
| **Export calibration** | −500 to +500 W; a small negative value backs off residual export to enforce true zero |

Full parameter table: Kent G3 Settings Reference.

## What zero export cannot guarantee

**Control over third-party grid-tie inverters.** An AC-coupled on-grid PV inverter with no comm link to the Kent hybrid keeps generating regardless of what the hybrid does. The Kent system can meter a third-party inverter's output — it cannot throttle it. Survey any retrofit site for existing grid-tie generation and quote honestly about export behaviour.

**Zero blips.** The difference between a fault and normal behaviour is the shape of the export trace. Momentary spikes on load steps are the loop working correctly. Sustained export above the limit is a fault. See the energy-flow test for pass criteria.

## The witness test is part of the configuration

No export-limited site is signed off on settings alone. With PV generating at a high level and site load minimised, the **utility meter** — not only the inverter display — must show no sustained export above the set limit. Run this test during a window that stresses the control loop, and capture the result.

Procedure and pass criteria: [Energy-Flow Test](/ct-meter/energy-flow-test).

## Common mistakes

<AccordionGroup>
  <Accordion title="Configured in settings, never witnessed on the utility meter">
    DISCOM penalties come from the utility meter reading, not the inverter display. The witness test is mandatory.
  </Accordion>

  <Accordion title="Settings copied from another brand's installation guide">
    Parameter names on Kent platforms are exact and not interchangeable with other manufacturers' menus.
  </Accordion>

  <Accordion title="Zero-export 'failure' that was a reversed CT the whole time">
    A reversed CT makes the inverter throttle in the wrong direction — inverting import and export. Fix the CT physically first before investigating settings.
  </Accordion>

  <Accordion title="Promising zero export on a retrofit site with a third-party GT inverter on the grid side">
    The Kent hybrid has no control channel to an uncoupled third-party inverter. Plan the metering and quote the limitation before signing the contract.
  </Accordion>
</AccordionGroup>

## Related pages

* [Energy-Flow Test](/ct-meter/energy-flow-test)
* [CT Basics](/ct-meter/ct-basics)
* [Direction & Location](/ct-meter/direction-and-location)
* [Kent M1 Settings Reference](/m1/settings-reference)
* [Kent G3 Settings Reference](/g3/settings-reference)