PSC 119.25(3)(b)6.6. Other equipment, such as other protective devices, supervisory control and alarms, telemetry and associated communications channel, that the public utility determines to be necessary and is compliant with applicable codes and standards. The public utility shall advise the applicant of any communications requirements after a preliminary review of the proposed installation.

PSC 119.26PSC 119.26 Certified paralleling equipment. DG paralleling equipment that a nationally recognized testing laboratory certifies as meeting the applicable type testing requirements of UL 1741 (September 28, 2021 revision) is acceptable for interconnection, without additional protection systems, to the distribution system. The applicant may use certified paralleling equipment for interconnection to a distribution system without further review or testing of the equipment design by the public utility, but the use of this paralleling equipment does not automatically qualify the applicant to be interconnected to the distribution system at any point in the distribution system. The public utility may still require an engineering review to determine the compatibility of the distributed generation system with the distribution system capabilities at the selected point of common coupling. DG paralleling equipment shall meet applicable codes and standards listed in PSC 119.025.

PSC 119.27PSC 119.27 Non-certified paralleling equipment.

PSC 119.27(1)(1) Any DG facility that is not certified under s. PSC 119.26 shall be equipped with protective hardware or software to prevent unintentional islanding and to maintain power quality. The applicant shall provide the final design of this protective equipment. The public utility may review and approve the design, types of protective functions, and the implementation of the installation. The applicant shall own the protective equipment installed at its facility.

PSC 119.27(2)(2) The applicant shall calibrate any protective system approved under sub. (1) to the specifications of the public utility. The applicant shall obtain prior written approval from the public utility for any revisions to specified protection system calibrations.

PSC 119.30PSC 119.30 Unintentional islanding test. The public utility may perform an unintentional islanding test or observe the automatic shutdown before giving final written approval for interconnection of the DG facility. The unintentional islanding test requires that the DG facility shall detect the island, cease to energize the local distribution system, and trip within two seconds of the formation of an island. The test shall be conducted as close to the point of common coupling as possible and should demonstrate that the DG facility does not energize the local distribution or transmission system. The test shall be conducted with all DG facility equipment operational and generating at an output that reflects site conditions acceptable to both parties. If a voltage is sustained after the simulation of an unintentional island, approval of the installation shall not be given until corrective measures are taken with a subsequent successful test.

PSC 119.31PSC 119.31 Commissioning tests for paralleling equipment in Categories 2 to 4. The public utility shall provide the acceptable range of settings for the paralleling equipment of a Category 2, 3, or 4 DG facility. The applicant shall program protective equipment settings into this paralleling equipment. The public utility may verify the protective equipment settings prior to allowing the DG facility to interconnect to the distribution system.

PSC 119.32PSC 119.32 Additional test. The public utility or applicant may, upon reasonable notice, re-test the DG facility installation after a failed test under s. PSC 119.30 or 119.31 or a disconnection under s. PSC 119.09. The party responsible for the re-testing shall bear the cost of the re-tests.

PSC 119.40PSC 119.40 Dispute Procedures.

PSC 119.40(1)(1) Applicants and public utilities shall attempt to resolve all disputes arising out of the interconnection process, including, but not limited to, the application and approval process under s. PSC 119.04 and disconnection under s. PSC 119.09, as described in this section.

PSC 119.40(2)(2) The applicant shall attempt to resolve the issue with the public utility by informing the public utility of the issue under dispute and the relief requested. The public utility shall:

PSC 119.40(3)(3) After the applicant has pursued available remedies with the public utility, the applicant may request that commission staff informally review the disputed issue and recommend terms of settlement.

PSC 119.40(3)(a)(a) The applicant’s request for an informal review may be made in any reasonable manner, such as by written request or telephone request direct to the commission. By telephone or written request public service commission staff may request information from the public utility to investigate the dispute.

PSC 119.40(3)(b)(b) The public utility shall designate employees for responding to disputes who are readily available and have an appropriate and sufficient authority level for investigating concerns raised by the commission and its staff. The public utility shall respond to commission staff’s request for investigation by providing a response to the commission within 10 business days. Commission staff may extend this time period if the public utility requests more time to complete its investigation. Based on the information provided by the applicant and the public utility, commission staff shall make an informal determination and communicate that determination in writing to both parties.

PSC 119.40(3)(c)(c) At least 7 days must elapse between the date commission staff communicates an informal determination and any disconnection of a distributed generation facility involved in the dispute.