Regulatory Interconnection

Regulatory Interconnection

California Interconnection Status for OutBack Power products

California is the first of many states in the US that requires both Power Control Systems certification and UL 1741 SA17/SA18 for all grid-interconnected inverters.

In California, the latest changes to the interconnection policies also refer to these regulatory requirements as California Rule 21 (Phases 1, 2, and 3).

The below table shows the regulatory specifications.

Regulatory InterconnectionRadian
UL 1741 SA (SA8-SA12) Complete
UL 1741 SA 13 Volt-Var (RPP) Complete
UL1741 SA Freq-Watt Volt-Wat (SA14-SA15) Complete
UL 1741 SA Disable/Permit Service and Limit Active Power (SA17-SA18) Complete
Common Smart Inverter Profile (CSIP) Conformance Complete (*Requires CSIP Bridge)
Monitor Key Data Scheduling Attestation Complete
PCS Certification Complete

Utility Communications

CA Rule 21 Phase 2, UL 1741 SB, and IEEE™ SunSpec 2030.5

What's Happening?

New changes to grid interconnection standards now require secure communications between the Utility Company and the inverter. These changes will be referenced in both IEEE™ 1547 (the Standard for Interconnecting Distributed Resources with Electric Power Systems) AND UL 1741 (the Standard for Inverters, Converters, Controllers and Interconnection System Equipment for Use with Distributed Energy Resources).

UL 1741 is moving forward to publish what will be called UL 1741SB (Supplement B) later this year and will directly refer to the IEEE 1547.1-2020. Under these changes Utilities may begin issuing event schedules for active and reactive power values as well as power modes and other settings. This includes remote monitoring and control of Distributed Energy Resources by the utility companies can inject power into the grid at times of peak usage.

Why CSIP Certified?

SunSpec 2030.5 CSIP Certified

To meet these new requirements, a product must be SunSpec 2030.5 CSIP certified. OutBack Power offers the CSIP Bridge for Radian and FXR/VFXR products. CSIP stands for Common Smart Inverter Profile. The configuration requirements described in the CSIP include:

  • Must use IEEE 2030.5-2018 communications protocols
  • Secure communications
  • Monitoring of data, including mirrored metering function sets for posting metered data, LogEven functions for alarms and response function sets for event acknowledgement.
  • Scheduling requirements, including effective start time, end time and only one active event per client
  • Support for eventual utility control to pro-actively support the grid
  • Not just Specified Power Factor, Volt-Var, Frequency-Watt, and Volt-Watt (UL1741 SA or IEEE 1547-2003)

Common Questions - Click to Learn More

  • What is OutBack Power's solution for Utility Communications?

    OutBack Power offers a communications device which connects to the homeowners’ network and provides secure communications between the Utility Company and the Inverter.

    This device is the product called the CSIP Bridge. It is SunSpec 2030.5 certified to provide secure communications

    CSIP Bridge works with either the Radian or the FXR. (GS8048A, GS4048A, FXR2524A, FXR3048A, VFXR3524A, and VFXR3648A.) A MATE3s running firmware 1.4.3 and above is required.

  • What is California Rule 21 Phase 2 and When Does it Take Effect?

    California Rule 21 Phase 2 is a modification to the interconnection tariff levied by the California Public Utility Commission (CPUC) that sets rules for performance, function, metering, and communications of generation and storage facilities. It takes effect on March 22, 2020.

    Phase 1 of California Rule 21 required Smart Inverters, aka Advanced Inverters or Grid Support Inverters. It was no longer enough to be simply a Grid-Interactive Inverter.

    Similarly, Phase 2 adds requirements that inverters support communications protocols for IOUs, DERs, and DER aggregators. At this time, the only supported communication protocol is IEEE™ 2030.5.

    When CA Rule 21 Phase 2 takes effect, inverter manufacturers must also attest that their products comply with Rule 21 Section Hh (Phase 3) Monitoring and Telemetry requirements (Function 1) and Scheduling capability requirements (Function 8). OutBack Power products comply with these functions. For more information, see the attestation for the relevant product:

    Attestation Form

  • What is UL 1741 SB and When Does it Take Effect?

    UL 1741 SB (Supplement B) is out for balloting now. The balloting period should close at the end of April, 2020. After that, expect comment and review, prior to adoption of 1741 Supplement B. It provides a part to certification to IEEE 1547-2018 and 1547.1-2020. When adopted, it may allow one or more communication protocols in addition to IEEE 2030.5.

  • What is IEEE SunSpec 2030.5 and How Does it Relate to the Above?

    California Rule 21 requires that, by default, Distributed Energy Resources within Investor Owned Utilities (IOU) must utilize the IEEE™ 2030.5-2018 networking standard in the manner described in the Common Smart Inverter Profile (CSIP). The SunSpec Alliance is a trade alliance of more than 100 solar and storage distributed energy industry participants, together pursuing information standards to enable “plug & play” system interoperability. IEEE 2030.5 is a secure IP-based communications protocol.

  • Technical Documentation
SunSpec 2030.5 CSIP Certified OutBack Products
Radian A Series Inverter/Chargers (GS8048A and GS4048A) - including FLEXpower Radian integrated systems
FXR/VFXR A Series Inverter/Chargers (FXR2524A, FXR3048A, VFXR3524A, and VFXR3648A)
**NOTE:** A MATE3s is required, for Radian and FXR/VFXR inverters, as is the CSIP Bridge product.


OutBack-provided .GIP files and special settings are NOT required. Contact your Utility Company for specific interconnection parameters which may be required to configure the CSIP Bridge.

Grid Support

UL 1741 SA

What's Happening?

As more PV is installed on electrical grids, grid operators need flexible tools to help ensure stability and reliability. Areas with the highest PV penetration rates (Hawaii and California) will soon require grid interconnected systems to have "Grid Support" functions.


OutBack Power is certifying the Radian Series inverter/chargers (along with the FXR Series in the near future) under the new UL 1741 SA test standard to demonstrate compliance with these new requirements from CA Rule 21 and HECO Rule 14H.

Common Questions - Click to Learn More


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