FOR APPLICATIONS TO INTERCONNECT
DISTRIBUTED GENERATION

Introduction:

This Initial Review Process was developed to create a path for selection and rapid approval of those Applications for Interconnection that do not require an Interconnection Study. The capitalized phrases used in this Appendix A have the same meanings as those in Section 8 of the proposed Rule 21.

Purpose:

The Initial Review determines:

a. If an Application qualifies for Simplified Interconnection;

b. If an Application can be made to qualify for Interconnection with supplemental review determining any potential additional requirements, or

c. If an Interconnection Study is required, the cost estimate and schedule for performing the Interconnection Study.

NOTE:

Failure to pass any screen only means that further review, and/or studies, are required before the DG project will be approved for interconnection with the Electrical Corporation. It does not mean that the DG cannot interconnect.

INITIAL REVIEW PROCESS FLOW CHART

Provide Completed Application.

Follow Net Metering Process (per P.U. Code Sec. 2827)

1. Does the DG qualify for net metering?

1.

2.

Yes

No

Yes

No

3. Will Power be exported across the PCC?

Yes

No

4. Is the Interconnection Equipment Certified for Application? or
does Interconnection Equipment have Interim EC Approval?

No

Yes

5. Is the aggregate DG Capacity on the Line Section less than 15% of Line Section peak load?

No

Yes

6. Is the DG Capacity 11 kVA or less?

Yes No

7. Is the Short Circuit Current Contribution screen met?

No

Yes

8. Is the Line Configuration screen met?

No

Yes Yes No

INITIAL REVIEW PROCESS DETAILS:

1. Does the DG qualify for net metering?

If YES, go to a separate process for net-metered DG (per P.U. Code Sec. 2827)

If NO, continue to next screen.

Significance:

1. Net-metered systems are covered by state legislation (refer to Section 2827 of the Public Utilities Code).

Criteria to Qualify for Net-Metering:

1. DG facility must comply with PUC Code Section 2827

2. Is the Point of Common Coupling (PCC) on a Networked Secondary System?

If NO, continue to next screen.

If YES, DG does not qualify for Simplified Interconnection.

Perform supplemental review.

Significance:

1. Special considerations must be given to DG on networked secondary distribution systems because of the design and operational aspects of network protectors. There are no such considerations for radial distribution systems.

3. Will power be exported across the PCC?

If YES, DG does not qualify for Simplified Interconnection.

Perform supplemental review.

If NO, DG must incorporate one of the following four options:

Option 1:

To insure power is never exported, a reverse power Protective Function must be implemented at the PCC.

Default setting shall be 0.1% (export) of transformer rating, with a maximum 2.0 second time delay.

Option 2:

To insure at least a minimum import of power, an under-power Protective Function must implemented at the PCC.

Default setting shall be 5% (import) of DG Gross Nameplate Rating, with maximum 2.0 second time delay.

Option 3:

To limit the incidental export of power, all of the following conditions must be met:

- The aggregate DG capacity of the Generating Facility must be no more than 25% of the nominal ampere rating of the Customer's Service Equipment;

- The total aggregate DG capacity must be no more than 50% of the transformer rating (This capacity requirement does not apply to customers taking primary service without an intervening transformer);

- The DG must be certified as non-islanding.

Option 4:

To insure that the relative size (capacity) of the DG compared to facility load results in no export of power without the use of additional devices, the DG capacity must be no greater than 50% of the customer's verifiable minimum annual load.

Significance:

1. Electrical Corporation's system does not need to be studied for load-carrying capability or DG power flow effects on EC voltage regulators since on-site DG reduces EC load.

2. Permits use of reverse-power relaying at the PCC as positive anti-islanding protection.

4. Is the Interconnection Equipment Certified for the Application or does the Interconnection Equipment have Interim EC Approval?

If NO, DG does not qualify for Simplified Interconnection.

Perform supplemental review.

If YES, continue to next screen.

Significance:

1. The Electrical Corporation does not need to review, or test, the DG's protective function scheme. Site commissioning testing may still be required to insure that the system is connected properly and that the protective functions are working properly.

- Basic protective function requirements met.

- Harmonic distortion limits met.

- Synchronizing requirements met.

- Flicker limitation requirements met.

- Pf regulation requirements met.

- Non-islanding requirements met.

- If used, reverse power function requirement met.

- If used, under-power function requirement met.

5. Is the aggregate DG Capacity on the Line Section less than 15% of Line Section Peak Load?

If YES, continue to next screen.

If NO, perform supplemental review to determine cumulative impact on Line Section.

Significance:

1. Low penetration of DG will have a minimal impact on operation and load restoration.

6. Is the DG Capacity 11 kVA or less?

If YES, DG qualifies for Simplified Interconnection.

If NO, continue to next screen.

Significance:

1. DG has minimal impact on fault current levels and any potential line overvoltages from loss of system neutral grounding.

7. Is Short Circuit Current Contribution screen met?

If NO, DG does not qualify for Simplified Interconnection.

Perform supplemental review.

If YES, continue to next screen.

Short Circuit Current Contribution Screen:

A. At primary side (high side) of dedicated distribution transformer, for the specified feeder, the sum of the Short Circuit Contribution Ratios (SCCR) of all DG's on the feeder must be less than or equal to 0.1.

B. At secondary (low side) of a shared distribution transformer, the short circuit contribution of the proposed DG must be less than or equal to 2.5% of the interrupting rating of the Customer's Service Equipment.

Significance:

No significant DG impact on:

· Distribution System's short circuit duty

· Distribution System fault detection sensitivity

· Distribution System relay coordination

· Distribution System fuse-saving schemes

8. Is the Line Configuration screen met?

If NO, then DG does not qualify for Simplified Interconnection.

Perform supplemental review.

If Yes, then DG

Line Configuration Screen:

Identify primary distribution line configuration. Based on proposed interconnection type, determine from table whether DG passes screen.

Primary Distribution Line Type	Type of Interconnection to Primary Distribution Line	Result/Criteria
Three-phase, three wire	Any	Pass screen
Three-phase, four wire	Single-phase, line-to-neutral	Pass screen
Three-phase, four wire (For any line that has such a section OR mixed 3 wire & 4 wire)	All others	To pass, aggregate DG Capacity must be less than or equal to 10% of Line Section Peak Load.

Significance:

1. If the Electrical Corporation's primary system is three-wire or the DG interconnection transformer is single-phase (line-to-neutral), then there is no concern about overvoltages to the Electrical Corporation's, or Customer, equipment caused by loss of system neutral grounding during the operating time of anti-islanding protection.

(END OF APPENDIX A)