S.D. Admin. R. 20:10:36:37

Current through Register Vol. 51, page 67, December 16, 2024

Section 20:10:36:37 - Tier 2 interconnection evaluation and screening criteria

A tier 2 interconnection shall use the following evaluation and screening criteria:

(1) For interconnection to a radial distribution circuit, aggregated generation on the circuit may not exceed 15 percent of the line section annual peak load as most recently measured at the substation or calculated for the line section. Aggregated generation includes the proposed small generator facility, FERC wholesale generators, and FERC wholesale generators with a higher queue position;

(2) For interconnection to the load side of spot network protectors, the aggregated other generation may not exceed the lesser of five percent of a spot network's maximum load or 50 kilowatts. Aggregated other generation includes the proposed small generator facility, FERC wholesale generators, and FERC wholesale generators with a higher queue position;

(3) General aggregate generation considerations are:

(a) In aggregate with other generation on the distribution circuit, the small generator facility may not contribute more than ten percent to the distribution circuit's maximum fault current at the point on the primary voltage distribution line nearest the point of interconnection;

(b) In aggregate with other generation, existing FERC wholesale generators, and FERC wholesale generators with a higher queue position on the distribution circuit, the small generator facility may not cause any distribution protective devices and equipment to be exposed to fault currents exceeding 90 percent of the short circuit interrupting capability. Distribution protective devices and equipment include: substation breakers, fuse cutouts, line reclosers, and other public utility equipment on the EDS. The small generator facility's point of interconnection may not be located on a circuit that already exceeds 90 percent of the short circuit interrupting capability;

(c) In aggregate with other generation, existing FERC wholesale generators, and FERC wholesale generators with a higher queue position interconnected to the distribution side of a substation transformer feeding the circuit where the small generator facility proposes to interconnect, the small generator facility may not exceed 10 megawatts in an area where there are known, or posted, transient stability limitations to generating units located in the general electrical vicinity;

(d) In aggregate with existing FERC wholesale generators, FERC wholesale generators with a higher queue position, and existing transmission loads, the small generator facility, may not cause a transmission system circuit to exceed its design capacity on the transmission system circuit directly connected to the distribution circuit where the interconnection is proposed; and

(e) If the small generator facility is to be interconnected on single-phase shared service line on the EDS, the aggregate generation capacity on the shared secondary line, including the proposed small generator facility, may not exceed 20 kilowatts;

(4) If the proposed small generator facility interconnection is to a primary line on the distribution system, the interconnection shall be done according to the following screening criteria, depending on the type of electrical service provided by the public utility:

(a) If the small generator facility is 3-phase or single-phase and is to be connected to a 3-phase 3-wire primary line, it must be connected phase-to-phase; and

(b) If the small generator facility is 3-phase or single-phase and is to be connected to a 3-phase 4-wire primary line, it must be connected line to neutral and effectively grounded;

(5) If the proposed small generator facility is single-phase and is to be interconnected on a center tap neutral of a 240 volt service line, its addition may not create a current imbalance between the two sides of the 240 volt service of more than 20 percent of the nameplate rating of the service transformer;

(6) The proposed small generator facility's point of interconnection may not be on a transmission line; and

(7) If the public utility's distribution circuit utilizes high speed reclosing with less than 2 seconds of interruption, the proposed generator may not be a synchronous machine.

S.D. Admin. R. 20:10:36:37

35 SDR 305, effective 7/1/2009.

General Authority: SDCL 49-34A-27, 49-34A-93.

Law Implemented: SDCL 49-34A-27, 49-34A-93.