The following general requirements shall govern the interconnection of photovoltaic (PV) and wind energy systems to the City of Shelby’s electric distribution systems.
(a) PV/Wind system output size.
(1) Residential. As determined by the property’s historic billing and Shelby Division of Electricity and Telecommunications system requirements with a maximum of 10kW.
(2) Commercial/Industrial. As determined by the property’s historic billing and Shelby Division of Electricity and Telecommunications system requirements with a maximum of 100kW.
(b) PV/Wind Inverter Output Voltage (AC) shall be 240 VAC nominal residential and 208/240/480 VAC commercial.
(c) The sources for distributed generation system standards are National Electric Code (NEC), Institute of Electric and Electronics Engineers (IEEE), Underwriters Laboratory (UL), American National Standards Institute (ANSI), National Electric Safety Code (NESC), International Electrotechnical Commission (IEC), and American Wind Energy Association (AWEA).
(1) PV systems shall meet the following standards: NEC 690 & 705, IEEE 1547, UL1741, UL1703, ANSI & NESC along with all applicable state and local standards.
(2) Wind turbine systems shall meet the following standards: NEC 694 & 705, IEEE 1547, UL1741, UL6142, IEC 61400, AWEA, ANSI & NESC along with all applicable state and local standards.
(3) Voltage range shall meet the following requirements:
Voltage Range (% Nominal) | Max. Clearing Time (sec)*
|
V <50% | 0.16 |
50%≤V<110% | 2.0 |
110%<V<120% | 1.0 |
V≥120% | 0.16 |
(*) Max clearing times for distributed energy resources <30kW;
Default clearing times for Distributed energy resources >30kW
(4) Frequency range shall meet the following requirements:
Frequency Range (Hz) | Max. Clearing Time (sec) |
f > 60.5 | 0.16 |
f < 57.0* | 0.16 |
59.8 < f < 57.0** | Adjustable (0.16 and 300) |
(*) 59.3 Hz if distributed energy resources < 30kW;
(**) For distributed energy resources > 30kW
(5) Voltage control is not permitted (IEEE 1547).
(6) Flicker shall not exceed maximum borderline of irritation curve (IEEE 1453).
(7) Harmonics (IEEE 519) shall meet the following requirements:
A. < 5% THD.
B. < 4% below 11th harmonic.
C. < 2% for 11th - 15th harmonic.
D. < 1.5% for 17th - 21st harmonic.
E. < 0.6% for 23rd - 33rd harmonic.
F. < 0.3% for 33rd and greater harmonic.
(8) Current imbalance shall meet the latest requirements for the following:
A. Current imbalance shall not be greater than 10%.
B. NEC.
C. IEEE.
D. NESC.
E. Local fire department.
(9) Grouping of disconnects. The DC disconnect (PV array/wind output), AC disconnect (inverter output), and revenue meter shall be grouped within ten feet of one another on the side of the building. The disconnects shall be permanently and clearly identified as to their purpose.
(Ord. 25-2016, passed 10-3-2016)