A6M+3SW Application Note for Solar Inverter DRM Control

Steps to configure the Auditor on the Onboarding and register the Auditor to SAPN Portal for DRM Control

Background

Wattwatchers is a Technology Partner of SA Power Networks in its capacity as a 'Relevant Agent' using Wattwatchers devices to perform the remote disconnection and reconnection under the South Australian Smarter Homes program.

Refer to our information on Solar Inverter Remote Disconnection Control for SA Smarter Homes for additional information and other supported methods and equipment.

This Application Note describes the implementation of the DRM Control method.

Relevant Agent Selection

The solar installer must select the Relevant Agent and Wattwatchers as the relevant technology when the equipment is registered with SA Power Networks as part of the standard network application process for grid-connected solar installations.

These steps include:

  • Small Embedded Generation (SEG) approval using Wattwatchers as the relevant technology.
  • Installation and commissioning of the solar disconnection equipment as per the relevant application notes.
  • Submit the Electrical Certificate of Compliance (eCoC) and select Wattwatchers as the relevant technology.

More information on this can be found on the SA Power Networks Relevant Agent website.

Hardware Overview

Wattwatchers Auditor Device

The Wattwatchers Auditor 6M+3SW is used in combination with a Contactor to send the DRM Control signals to the inverter.

The A6M+3SW switching outputs are designed to support application with Contactors supplied by Wattwatchers with a 240V coil control voltage. The A6M+3SW switching outputs do not support a direct connection to the inverter DRM interface and must be used with an external Contactor as described in this Application Note.

The Contactor is installed to connect two pins together on the solar inverter to assert the DRM0 (disconnect) or DRM5 (stop generation) signal.

Contactor Ratings

The Contactor must be rated to support the maximum voltage and current required for the DRM port of the solar inverter equipment. Please refer to the solar inverter documentation to confirm these requirements.

Wattwatchers supplies Contactors in the following configurations:

  • Single Phase applications: Two Pole 240V 25A (1x NO with 1xNC) with 240V coil
  • Three Phase applications: Three Pole 240V 25A (NO or NC) with 240V coil

Please contact us if other Contactor ratings or configurations are required.

Step 1 - Solar Inverter Configuration

Please refer to the solar inverter documentation to enable the DRM interface.

Step 2 - Wattwatchers Auditor Installation

The Wattwatchers Auditor 6M+3SW is installed in the customer switchboard with an appropriate protection device such as an RCBO or Breaker depending on the local jurisdictional requirements.

The Contactor is installed to connect two pins together on the Solar Inverter DRM interface to assert the DRM0 (disconnect) or DRM5 (stop generation) signal.

Current Transformers are installed on the Solar AC Supply to monitor the generation and also on the Main Incoming Supply to monitor the total site load.

The equipment is installed as per the information provided in the Wattwatchers A6M+3SW Quick Start Guide and the Wiring Diagrams as follows.

DRM0 Control for Single-Phase Supply with Single-Phase Solar Inverter

DRM0 Control for Three-Phase Supply with Single-Phase Solar Inverter

DRM0 Control for Three-Phase Supply with Three-Phase Solar Inverter

The same method can be used to send the DRM5 signal if this is available on two pins of the inverter DRM interface and can be used in place of the DRM0 connections described in the wiring diagrams.

Please refer to the solar inverter documentation to confirm the connections to the solar inverter DRM interface.

Step 3 - Wattwatchers Auditor Configuration

The Wattwatchers Onboarding application is used to configure the device as part of the normal installation process.

The following settings are required in the Wattwatchers Onboarding application for the SA Smarter Homes requirements.

Site Configuration

In the Start section of the Onboarding application, set the site address and timezone as follows.

Label/Name: Set this as the customer address including street name and suburb (eg: 123 Smith Street, Adelaide)

Timezone: Australia/Adelaide (or relevant local timezone if not installed in South Australia)

The following shows an example configuration.

Press the Save button to store this configuration before moving to the next step.

Switches Configuration

In the Switches section of the Onboarding application, select the relevant Switch device (Switch 1, Switch 2 or Switch 3) depending on which switching interface the Contactor has been wired into. In all of the example wiring diagrams, this is Switch 1.

Category: Solar export control

Custom Label: User-defined label (eg: Solar Inverter 1)

Contactor Type: Normally Open

Solar Control Parameters

Control Method: DRM0 or DRM5

Related NMI: Customer NMI (if available)

System AC Output (kW): Solar AC Output Rating (in integer or decimal format eg: 5 or 5.0)

The following shows an example configuration. 

Press the Save Changes button to store this configuration before moving to the next step.

Step 4 - System Commissioning Test

Using the Wattwatchers Onboarding application, the following process is performed.

  1. Navigate to the Energy section of the Onboarding application to display the current energy being generated by the solar system and note this value should be a positive value when the system is generating normally.
  2. Navigate to the Switches section of the Onboarding application and activate the disconnection function by selecting the control slider for the relevant switch and selecting ON.
  3. The Contactor should operate within around 5-10 seconds to signal the solar inverter equipment to disconnect or stop generation.
  4. Navigate to the Energy section of the Onboarding application to display the current energy being generated by the solar system and ensure this value is zero.
  5. Navigate to the Switches section of the Onboarding application to reconnect the solar system by selecting the control slider for the relevant switch and selecting OFF.
  6. The Contactor should operate within around 5-10 seconds to reconnect the solar inverter equipment.
  7. Navigate to the Energy section of the Onboarding application to display the current energy being generated by the solar system and note this value should increase as the solar inverter returns to normal operation.

Step 5 - Relevant Agent Registration

Wattwatchers supports multiple Relevant Agents. In the following example, SA Power Networks has been used as the Relevant Agent.

Please confirm the Relevant Agent and relevant technology selections with your Solar Retailer.

Solar Retailer Example with SA Power Networks as Relevant Agent

When registering the Embedded Generation equipment on the SA Power Networks Portal, select the preferred Relevant Agent (SA Power Networks in this example) with the option for Wattwatchers that is "Internet connected Wattwatchers Auditor 6M or 6W device with Contactor switching for all inverters, or connected to inverters DRM port for supported models" in this example.

SAPN RA Portal WW Registration

More Information or Support

Please contact us for additional information or assistance.