Chapter PSC 119

PSC 119.31   Commissioning tests for paralleling equipment in Categories 2 to 4.

PSC 119.32   Additional test.

PSC 119.40   Dispute Procedures.

subch. I of ch. PSC 119 Subchapter I — General

PSC 119.01 PSC 119.01 Scope. This chapter implements s. 196.496, Stats. It applies to all DG facilities with a capacity of 15 MW or less that are interconnected, or whose owner seeks to have interconnected, to an electric public utility’s distribution system. It also applies to all electric public utilities to whose distribution systems a DG facility is interconnected, or to which interconnection is sought. These rules establish uniform statewide standards for the interconnection of DG facilities to an electric distribution system.

PSC 119.01 History History: CR 03-003: cr. Register January 2004 No. 577, eff. 2-1-04.

PSC 119.02 PSC 119.02 Definitions. In this chapter:

PSC 119.02(1) (1) “ANSI” means American National Standards Institute.

PSC 119.02(2) (2) “Applicant” means the legally responsible person applying to a public utility to interconnect a DG facility to the public utility’s distribution system.

PSC 119.02(3) (3) “Application review” means a review by the public utility of the completed standard application form for interconnection, to determine if an engineering review or distribution system study is needed.

PSC 119.02(4) (4) “Category 1” means a DG facility with an export capacity of 20 kW or less. A DG facility comprised of a resource no larger than 20 kW with a non-exporting energy storage system no larger than 20 kW shall be considered a Category 1 system.

PSC 119.02(5) (5) “Category 2” means a DG facility with an export capacity of greater than 20 kW and not more than 200 kW. The nameplate rating shall be used instead of the export capacity for this definition if the non-exporting energy storage system is larger than 20 kW.

PSC 119.02(6) (6) “Category 3” means a DG facility with an export capacity of greater than 200 kW and not more than 1 MW. The nameplate rating shall be used instead of the export capacity for this definition if the non-exporting energy storage system is larger than 200 kW.

PSC 119.02(7) (7) “Category 4” means a DG facility with an export capacity of greater than 1 MW and not more than 15 MW.

PSC 119.02(8) (8) “Certified equipment” means a generating, control or protective system that has been certified by a nationally recognized testing laboratory as meeting acceptable safety and reliability standards.

PSC 119.02(9) (9) “Commission” means the public service commission of Wisconsin.

PSC 119.02(10) (10) “Commissioning test” means the process of documenting and verifying the performance of a DG facility so that it operates in conformity with the design specifications.

PSC 119.02(11) (11) “Customer” means any person who is receiving electric service from a public utility’s distribution system.

PSC 119.02(12) (12) “DG” means distributed generation.

PSC 119.02(13) (13) “DG facility” has the meaning given in s. 196.496 (1), Stats.

PSC 119.02(14) (14) “Distribution feeder” means an electric line from a public utility substation or other supply point to customers that is operated at 50 kV or less, or as determined by the commission.

PSC 119.02(15) (15) “Distribution system” means all electrical wires, equipment, and other facilities owned or provided by a public utility that are normally operated at 50 kV or less.

PSC 119.02(16) (16) “Distribution system study” means a study to determine if a distribution system upgrade is needed to accommodate the proposed DG facility and to determine the cost of any such upgrade.

PSC 119.02(16d) (16d) “Energy storage system” means a device or devices that capture energy produced at one time, store that energy for a period of time, and deliver that energy as electricity for use at a future time.

PSC 119.02(16h) (16h) “Energy storage system max continuous output kW in alternating current” means the maximum rated continuous power output of the energy storage system.

PSC 119.02 Note Note: This defined term should be used when completing the standard application form, PSC Form 6031.

PSC 119.02(16p) (16p) “Energy storage system max usable energy kWh in alternating current” means the maximum rated amount of energy stored in the energy storage system.

PSC 119.02 Note Note: This defined term should be used when completing the standard application form, PSC Form 6031.

PSC 119.02(16t) (16t) “Energy storage system peak output kW in alternating current” means while grid interactive, the maximum short duration rated output power of the energy storage system to the distribution system.

PSC 119.02 Note Note: This defined term should be used when completing the standard application form, PSC Form 6031.

PSC 119.02(17) (17) “Engineering review” means a study that may be undertaken by a public utility, in response to its receipt of a completed standard application form for interconnection, to determine the suitability of the installation.

PSC 119.02(17m) (17m) “Export capacity kW in alternating current” means the amount of power that can be transferred from the DG facility to the distribution system. Export capacity is the lesser of the following:

PSC 119.02(17m)(a) (a) The nameplate rating.

PSC 119.02(17m)(b) (b) If limited using any approved means, that limited amount.

PSC 119.02(18) (18) “Fault” means an equipment failure, conductor failure, short circuit, or other condition resulting from abnormally high amounts of current from the power source.

PSC 119.02(19) (19) “IEEE” means Institute of Electrical and Electronics Engineers.

PSC 119.02(20) (20) “Interconnection” means the physical connection of a DG facility to the distribution system so that parallel operation can occur.

PSC 119.02(21) (21) “Interconnection disconnect switch” means a mechanical device used to disconnect a DG facility from a distribution system.

PSC 119.02(22) (22) “Inverter” means a machine, device, or system that converts direct current power to alternating current power.

PSC 119.02(23) (23) “Islanding” means a condition on the distribution system in which a DG facility delivers power to customers using a portion of the distribution system that is electrically isolated from the remainder of the distribution system.

PSC 119.02(24) (24) “kV” means kilovolt.

PSC 119.02(25) (25) “kW” means kilowatt. Unless otherwise specified, the definition references units in alternating current.

PSC 119.02(26) (26) “Material modification” means any modification that changes the maximum electrical output of a DG facility or changes the interconnection equipment, including:

PSC 119.02(26)(a) (a) Changing from certified to non-certified devices.

PSC 119.02(26)(b) (b) Replacing a component with a component of different functionality or UL listing.

PSC 119.02(27) (27) “MW” means megawatt. Unless otherwise specified, the definition references units in alternating current.

PSC 119.02(27m) (27m) “Nameplate rating alternating current” means the sum total of maximum continuous rated power (kW) output while grid connected of all of a DG facility’s constituent generating units or energy storage systems, or both, as identified on the manufacturer nameplate, regardless of whether it is limited by any approved means.

PSC 119.02(28) (28) “Nationally recognized testing laboratory” means any testing laboratory recognized by the U.S. Department of Labor Occupational Safety and Health Administration’s accreditation program.

PSC 119.02 Note Note: A list of nationally recognized testing laboratories is available at www.osha.gov/dts/otpca/nrtl/index.html.

PSC 119.02(29) (29) “Network service” means 2 or more primary distribution feeders electrically connected on the low voltage side of 2 or more transformers, to form a single power source for any customer.

PSC 119.02(30) (30) “Parallel operation” means the operation, for longer than 100 milliseconds, of an on-site DG facility while the facility is connected to the energized distribution system.

PSC 119.02(31) (31) “Paralleling equipment” means the generating and protective equipment system that interfaces and synchronizes a DG facility with the distribution system.

PSC 119.02(32) (32) “Point of common coupling” means the point where the electrical power system of the applicant seeking to interconnect a DG facility is electrically connected to the distribution system. The point of common coupling is equivalent, in most cases, to the service point as specified by the public utility and described in the National Electric Code and National Electrical Safety Code.

PSC 119.02 Note Note: National electric codes are adopted in Wisconsin Electrical Safety Code Volumes 1 and 2, as found in ch. PSC 114 and ch. SPS 316.

PSC 119.02(32m) (32m) “Power factor” means the ratio of active power to apparent power.

PSC 119.02(33) (33) “Public utility” has the meaning given in s. 196.01 (5), Stats.

PSC 119.02(34) (34) “Standard application form” means PSC Form 6031. The standard application form has supplements designed to collect information specific to different installations and technologies.

PSC 119.02(35) (35) “Standard interconnection agreement” means PSC Form 6029 for Category 1 facilities or PSC Form 6030 for Category 2 to 4 DG facilities.

PSC 119.02 Note Note: A copy of PSC Forms 6029 to 6033 can be obtained can be obtained at no charge from the local electric utility or from the Public Service Commission, PO Box 7854, Madison, WI 53707-7854.

PSC 119.02(35g) (35g) “Standard pre-application request form” means PSC Form 6032.

PSC 119.02(35r) (35r) “Standard pre-application report” means the information provided on PSC form 6033 in response to completed requests submitted through PSC Form 6032.

PSC 119.02(36) (36) “Telemetry” means transmission of DG operating data and settings using telecommunications techniques. It may also include controls and two-way communication.

PSC 119.02(37) (37) “UL” means Underwriters Laboratory.

PSC 119.02(38) (38) “Working day” has the meaning given in s. 227.01 (14), Stats.

PSC 119.02 History History: CR 03-003: cr. Register January 2004 No. 577, eff. 2-1-04; CR 22-077: am. (4) to (7), cr. (16d) to (16t), (17m), am. (25), (27), cr. (27m), am. (32), cr. (32m), am. (34), cr. (35g), (35r), am. (36) Register April 2024 No. 820, eff. 5-1-24; correction in numbering of (17m) (a), (b) made under s. 13.92 (4) (b) 1., Stats., Register April 2024 No. 820.

PSC 119.025 PSC 119.025 Adoption of standards by reference.

PSC 119.025(1) (1) Adoption of standards. The standards, IEEE Std 1547-2018: IEEE Standard for Interconnection and Interoperability of Distributed Energy Resources with Associated Electric Power Systems Interfaces, published April 6, 2018, and IEEE Std 1547.1-2020: IEEE Standard Conformance Test Procedures for Equipment Interconnecting Distributed Energy Resources with Electric Power Systems and Associated Interfaces, are hereby incorporated by reference into this chapter.

PSC 119.025(2) (2) Consent to incorporate by reference. Pursuant to s. 227.21, Stats., the attorney general has consented to incorporate by references these standards contained in Std 1547-2018 and IEEE Std 1547.1-2020. Copies of IEEE Std 1547-2018 and IEEE Std 1547.1-2020 are on file in the offices of commission and the legislative reference bureau.

PSC 119.025 History History: CR 22-077: cr. Register April 2024 No. 820, eff. 5-1-24; correction in (1) made under s. 35.17, Stats., Register April 2024 No. 820.

subch. II of ch. PSC 119 Subchapter II — General Requirements

PSC 119.03 PSC 119.03 Designated point of contact. Each public utility shall designate one point of contact for all customer inquiries related to DG facilities and from which interested parties can obtain installation guidelines and the appropriate standard commission application and interconnection agreement forms. Each public utility shall have current information concerning its DG point of contact on file with the commission.

PSC 119.03 History History: CR 03-003: cr. Register January 2004 No. 577, eff. 2-1-04.

PSC 119.04 PSC 119.04 Application process for interconnecting DG facilities. Public utilities and applicants shall complete the following steps regarding interconnection applications for all classes of DG facilities, in the order listed:

PSC 119.04(1) (1) The public utility shall respond to each request for DG interconnection by furnishing, within 5 working days, its guidelines and the public utility’s electric service rules, representative or sample one-line schematic diagrams, and the appropriate standard application form. Public utilities shall also make these materials accessible on their website.

PSC 119.04(2) (2) The applicant shall complete and submit the standard application form to its public utility. An application shall not be considered submitted until the applicant submits a form and pays applicable application review fees under s. PSC 119.08 (1).

PSC 119.04(2m) (2m) All submitted applications shall be reviewed for completeness in the order in which they fulfill the requirements of sub. (2), regardless of whether the project is from an outside applicant or the public utility.

PSC 119.04(3) (3) Within 10 working days of receiving a new or revised application and application fee, the public utility shall notify the applicant whether the application is complete.

PSC 119.04(3g) (3g) All complete applications shall be processed in the order in which they are deemed complete, regardless of whether the project is from an outside applicant or the public utility. Reasonable exceptions may be made to account for the location of the proposed DG facility or other technical considerations, provided there is no material adverse impact on processing of other complete applications when an exception is made. Exceptions may also be made if an applicant exceeds any timing requirements identified in s. PSC 119.06. If the public utility misses any timing requirements in s. PSC 119.06, the order in which the application is processed shall not be affected.

PSC 119.04(3r) (3r) Where multiple DG facilities are electrically interrelated, processing complete applications jointly may be appropriate to increase cost and time efficiencies. If the public utility and the applicant mutually agree, the application may be studied in a group with other applications.

PSC 119.04(4) (4) Public utilities and applicants shall complete the following steps for processing interconnection applications, in the order listed:

PSC 119.04(4)(a) (a) Within 10 working days of determining that the application is complete, the public utility shall complete its application review and notify the applicant of its findings. If the public utility determines, on the basis of the application review, that an engineering review is needed, the notification shall state a nonbinding estimate of that review. If the application review shows that an engineering review is not needed, the applicant may install the DG facility and need not complete the steps described in pars. (b) through (g).

PSC 119.04(4)(b) (b) The applicant shall provide written notification to proceed and full payment of the estimated cost of the engineering review within 15 working days of receiving the public utility’s notification under par. (a). At the request of the applicant, the utility may provide a 15 working day extension of the deadline to provide notification to proceed and full payment. If notification and payment have not been received by the utility within 30 working days after the deadline to accept, the interconnection application shall be deemed withdrawn.

PSC 119.04(4)(c) (c) Upon receiving from the applicant written notification to proceed and full payment of the estimated cost of the engineering review, the public utility shall complete an engineering review and notify the applicant of the results within the following times:

PSC 119.04(4)(c)1. 1. Category 1 DG application, 10 working days.

PSC 119.04(4)(c)2. 2. Category 2 DG application, 15 working days.

PSC 119.04(4)(c)3. 3. Category 3 DG application, 20 working days.

PSC 119.04(4)(c)4. 4. Category 4 DG application, 40 working days.

PSC 119.04(4)(d) (d) If the engineering review indicates that a distribution system study is necessary, the public utility shall include, in writing, a nonbinding cost estimate of the study in its engineering review. To proceed with a distribution system study, the applicant shall provide the utility with written notification of acceptance and full payment of the estimated study costs within 15 working days of receiving the engineering review. At the request of the applicant, the utility may provide a 15 working day extension of the deadline to provide notification to proceed and full payment. If notification and payment have not been received by the utility within 30 working days after the deadline to accept, the interconnection application shall be deemed withdrawn.