WAC 480-108-020   Technical standards for interconnection.  (1) General interconnection requirements.

     (a) The interconnection of a generating facility with the electrical company's electric system, the modification of a generating facility that is currently interconnected to the electrical company's electric system, or the modification of an existing interconnection must meet all minimum technical specifications applicable, in their most current approved version, as set forth in WAC 480-108-999.

     (b) Interconnection of a generation facility with a nameplate capacity rating of 300 kW or less must comply with all applicable requirements in Table 1.

Table 1. 300 kW Capacity or Less.

	Single-Phase		Three-Phase
Feature	< 50 kW Inverter based	< 50 kW Noninverter based	< 300 kW Inverter based	< 300 kW Noninverter based
IEEE 1547 compliant	X	X	X	X
UL 1741 listed	X		X
Interrupting devices (capable of interrupting maximum available fault current)	X (8)	X	X (8)	X
Interconnection disconnect device (manual, lockable, visible, accessible)	X (1)	X	X	X
System protection		X (3)(4)(6)		X (3)(4)(5)(6)
Over-voltage trip	X (8)	X	X (8)	X
Under-voltage trip	X (8)	X	X (8)	X
Over/under frequency trip	X (8)	X	X (8)	X
Automatic synchronizing check		X		X
Ground over-voltage or over-current trip for utility system faults				X (2)
Power factor		X (7)		X (7)

	Notes:
	X - Required feature (blank = not required).
	(1) - Electrical company may choose to waive this requirement.
	(2) - May be required by electrical company; selection based on grounding system.
	(3) - No single point of failure shall lead to loss of protection.
	(4) - All protective devices shall fully meet the requirements of American National Standards Institute C37.90.
	(5) - Electrical company will specify the transformer connection.
	(6) - It is the customer's responsibility to ensure that its system is effectively grounded as defined by IEEE Std. 142 at the point of common coupling.
	(7) - Variance may be allowed based upon specific requirements per electrical company review. Charges may be incurred for losses.
	(8) - UL 1741 listed equipment provides required protection.

     (c) Any single or aggregated generating facility with a capacity greater than 50 kW requires a three-phase interconnection.

     (d) The specification and requirements in this section are intended to mitigate possible adverse impacts caused by the generating facility on electrical company equipment and personnel and on other customers of the electrical company. The specifications and requirements in this section are not intended to address protection of the generating facility or its internal load, or generating facility personnel. The interconnection customer is responsible for complying with the requirements of all appropriate standards, codes, statutes, and authorities to protect its own facilities, personnel, and loads.

     (e) The specifications and requirements in this section apply generally to the interconnection to an electrical company's electric system of customer-owned and operated electric equipment and any other facilities or equipment not owned by the electrical company to which interconnection agreement(s) apply throughout the period encompassing the interconnection customer's installation, testing and commissioning, operation, maintenance, decommissioning and removal of equipment. The electrical company may verify compliance at any time, with reasonable notice.

     (f) The electrical company may refuse to establish or maintain interconnection with any interconnection customer that fails to comply with the requirements in (f)(i), (ii) and (iii) of this subsection. However, at its sole discretion, the electrical company may approve alternatives that satisfy the intent of, and/or may excuse compliance with, any specific elements of these requirements except local, state and federal building codes.

     (i) Code and standards. All interconnections must conform to all applicable codes and standards for safe and reliable operation. Among these are the National Electric Code (NEC); National Electric Safety Code (NESC); the standards of the Institute of Electrical and Electronics Engineers (IEEE); the standards of the North American Electric Reliability Corporation (NERC); the standards of the Western Electricity Coordinating Council (WECC); American National Standards Institute (ANSI); Underwriters Laboratories (UL) standards; local, state and federal building codes, and any electrical company's written electric service requirement approved by the commission. Electrical companies may require verification that an interconnection customer has obtained all applicable permit(s) for the equipment installations on its property.

     (ii) Safety. All safety and operating procedures for interconnection facilities must comply with the Occupational Safety and Health Administration (OSHA) Standard at 29 CFR 1910.269, the NEC, Washington Administrative Code (WAC) rules, the Washington Industrial Safety and Health Administration (WISHA) Standard, and equipment manufacturer's safety and operating manuals.

     (iii) Power quality. Installations must be in compliance with all applicable standards including, without limitation, IEEE Standard 519 Harmonic Limits, and IEEE Standard 141 Flicker as measured at the PCC.

     (2) Specific interconnection requirements.

     (a) The electrical company must verify that the interconnection customer has furnished and installed on its side of the meter, a UL-approved safety disconnect switch that can fully disconnect the interconnection customer's generating facility from the electrical company's electric system. The disconnect switch must be located adjacent to electrical company meters and shall be of the visible break type in a metal enclosure that can be secured by a padlock. The disconnect switch must be accessible to electrical company personnel at all times.

     (b) The requirement in (a) of this subsection may be waived by the electrical company if the interconnection customer:

     (i) Provides interconnection facilities that the interconnection customer can demonstrate, to the satisfaction of electrical company, perform physical disconnection of the generating equipment supply internally; and

     (ii) Agrees that its service may be disconnected entirely if generating equipment must be physically disconnected for any reason.

     Such waiver granted by the electrical company to the interconnection customer must be explicit and in writing.

     (c) The electrical company has the right to disconnect the generating facility at the disconnect switch:

     (i) When necessary to maintain safe electrical operating conditions;

     (ii) If the generating facility does not meet required standards; or

     (iii) If the generating facility at any time adversely affects or endangers any person, the property of any person, the electrical company's operation of its electric system or the quality of electrical company's service to other customers.

     (d) Nominal voltage and phase configuration of interconnection customer's generating facility must be compatible with the electrical company's system within generally accepted engineering standards including without limitation IEEE Standards 141 and 519 at the point of common coupling.

     (e) The electrical company must verify on the basis of evidence provided by the interconnection customer that a generating facility interconnected to a grid network distribution system or a spot network distribution system will not impair public safety or quality of service to the electrical company's other customers as a result of reverse current flow through the electrical company's network protectors.

     (f) All instances of interconnection to spot network distribution systems require review, studies as necessary, and written approval by the electrical company.

     (g) All instances of interconnection to grid network distribution systems require review, studies as necessary, and written approval by the electrical company.

     (h) Closed transition transfer switches are not allowed in network distribution systems.

     (3) Specifications applicable to all inverter-based interconnections. In addition to the requirements contained in subsections (1) and (2) of this section, the interconnection of any inverter-based generating facility with the electrical company's electric system, or the modification of an existing interconnection with an inverter-based generating facility must meet the following additional technical specifications, in their most current approved version:

     (a) IEEE Standard 1547, Standard for Interconnecting Distributed Resources with Electric Power Systems;

     (b) UL Standard 1741, Inverters, Converters, and Controllers for Use in Independent Power Systems. Equipment must be UL listed; and

     (c) IEEE Standard 929, IEEE Recommended Practice for Utility Interface of Photovoltaic (PV) Systems.

     (4) In addition to the requirements in subsections (2) and (3) of this section, all noninverter-based interconnections and all inverter-based interconnections failing to meet the requirements of subsection (3) of this section may require more detailed electrical company review. The electrical company must demonstrate the need for additional testing and approval of equipment if the same equipment has been tested and approved previously for any of the electrical company's interconnection customers. Electrical companies may require interconnection customers to pay for needed testing and approval of the equipment proposed to be installed to ensure compliance with applicable technical specifications, in their most current approved version, including:

     (a) IEEE Standard 1547, Standard for Interconnecting Distributed Resources with Electric Power Systems, for systems 10 MVA or less; and

     (b) ANSI Standard C37.90, IEEE Standard for Relays and Relay Systems Associated with Electric Power Apparatus.

     (5) The electric company may require interconnection customers proposing noninverter-based interconnection to submit a power factor mitigation plan for electrical company review and approval.



[Statutory Authority: RCW 80.01.040 and 80.04.160. 07-20-059 (Docket UE-060649, General Order 545), § 480-108-020, filed 9/27/07, effective 10/28/07; 06-07-017 (Docket No. UE-051106, General Order No. R-528), § 480-108-020, filed 3/6/06, effective 4/6/06.]