> ## 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.

# Kent M1 CT and Meter — Installation and Fault Diagnosis

> Arrow-to-grid CT placement rule, terminal wiring, supported meter models, RS485 connections, AC-coupled retrofit schemes, and wrong-CT fault codes.

The Kent M1 senses grid power flow using the in-box CT or a supported energy meter. Place and orient the CT correctly and zero-export, self-use, and the energy display all work. Get it wrong and the inverter operates blind — or actively misbehaves. This page covers placement, wiring, meter options, and what the fault codes tell you.

<Warning>
  **For trained and authorised installers only.** Isolate the AC conductor before clamping anything around it.
</Warning>

## The CT rule

Install the CT using this three-step procedure:

<Steps>
  <Step title="Choose the right conductor">
    Clamp the CT on the **grid main L (live) conductor** at the grid connection point. Never clamp on a load branch, and never clamp around L and N together.
  </Step>

  <Step title="Orient the arrow toward the grid">
    The **arrow on the CT must point toward the grid** — this is the universal Kent rule across all platforms. Reversed CT causes reversed power signs and incorrect control behaviour.
  </Step>

  <Step title="Close and land the leads">
    Close the CT cap until it **clicks** into lock. Land the CT leads on **CT+** and **CT−** of the 16-way communication strip.
  </Step>
</Steps>

On the LCD, navigate to the Advanced page and set:

* **Meter CT orientation:** towards the grid
* **CT Ratio:** exactly as shown on the shipped CT's nameplate

<Warning>
  **Pending Kent validation.** \[KNB-VAL-08]
  The shipped CT scheme and ratio per Kent SKU are under confirmation. Until published here: **read the ratio off the CT's nameplate and enter exactly that value** — never assume a factory default is correct.
</Warning>

## Meter option

Where a supported energy meter is used instead of, or alongside, the CT, the following models are supported:

| Model         | Type                          |
| ------------- | ----------------------------- |
| DDSU666       | Single-phase, 2P 1CT          |
| DTSU666       | Three-phase, 4P 3CT or 4P 6CT |
| ADL200N-CT    | Single-phase CT meter         |
| ADL400N-CT    | Three-phase CT meter          |
| ADW200-D16-2S | Multi-function meter          |

Wire the meter RS485 interface as follows:

* **Meter A → METER(A)** terminal on the 16-way strip
* **Meter B → METER(B)** terminal on the 16-way strip

On the three-phase meter's RJ45: A maps to **pin 3**, B maps to **pin 6**.

<Note>
  Follow the wiring figure for the exact meter model and CT count — position and direction errors show up as wrong power readings and incorrect energy totals.
</Note>

## AC-coupled retrofit schemes

For sites with an existing grid-tied solar inverter being retrofitted with a Kent M1:

* **Single-phase home:** use a **3-CT meter** with CT-A on the grid conductor and CT-B on the existing solar inverter output.
* **Three-phase supply:** use the **6-CT scheme** — three CTs on the grid and three on the existing solar inverter.

## Wrong-CT symptoms

Use these symptoms to diagnose a CT problem on site:

| Symptom                                                    | Likely cause                                           |
| ---------------------------------------------------------- | ------------------------------------------------------ |
| **E106** fault on LCD                                      | CT abnormal — check connection and conductor selection |
| **E107** fault on LCD                                      | CT reversed — flip the CT arrow direction              |
| Load reading 0 W                                           | CT clamped around L and N together                     |
| Import/export signs flipped or battery discharging to grid | CT reversed or on the wrong conductor                  |

**Witness test at commissioning:** with grid on and PV off, the display must show import. Then energise a heavy load and confirm the sign and magnitude change correctly. 📷

## Common mistakes

* CT clamped on a sub-circuit branch "because the main cable was hard to reach" — the control logic goes blind to everything outside that branch.
* CT ratio typed from memory instead of the CT nameplate. \[KNB-VAL-08]
* Meter RS485 A and B swapped — meter comm fault, no grid data on the display.
* CT lead extended with random cable — keep the run within the supplied lead's design length.

## When to escalate

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.

## Related pages

* [Kent M1 Commissioning](/m1/commissioning)
* [Kent M1 Settings Reference](/m1/settings-reference)
* [Kent M1 AC Wiring](/m1/ac-wiring)