December 12, 2013 MWG Meeting Topics for Discussion

Topics for discussion: 9:00 am – 9:05 amA.) Reading of ERCOT Anti-Trust Rules (D.DiSanto) 9:05 am – 10:30 amB.) NPRR-570 (Reduce RTM Settlement Timeline to Operating Day Plus Five): Impacts on notices when EPS meter data are required on the same business day to support settlements and non-business day coverage (D. Tucker and P. Vinton) 10:30 am – 10:40 amBreak 10:40 am – 12:00 nnC.) NPRR-570 discussions continued and overview of SMOGRR related to NPRR :00 nn – 1:15 pmBreak 1:15 pm – 1:45 pmD.) Follow-up discussion on CCVT 5-year re- certification (T. Davis/H. Perez/D. Maul)

Topics for discussion: 1:45 pm – 2:15 pmE.) Follow-up discussion on Parallel CT clarification per SMOG (e) (H. Perez) 2:15 pm – 2:45 pmF.) Follow-up discussion on Loss of potential per SMOG define specific threshold voltage (C. Wang) 2:45 pm – 3:00 pmBreak 3:00 pm – 3:15 pmG.) Follow-up discussion on EPS metering sites with Provisionally Approved status (T. Davis) 3:15 am – 3:30 pmH.) Follow-up discussion on TDSP’s submission of nameplate photos of newly-installed instrument transformers - CTs & VTs (H. Perez)

Topics for discussion: 3:30 pm – 3:55 pmI.) New or other business items (D. DiSanto) 3:55 pm – 4:00 pmJ.) Meeting wrap-up (D. DiSanto)

A.) Legal Disclaimers and Admonitions Antitrust Admonition ERCOT strictly prohibits market participants and their employees who are participating in ERCOT activities from using their participation in ERCOT activities as a forum for engaging in practices or communications that violate antitrust laws. The ERCOT Board has approved guidelines for Members of ERCOT Committees, subcommittees and working groups to be reviewed and followed by each market participant attending ERCOT meetings. For details, please review the guidelines in the attachments tab of this presentation (if available).

B. NPRR-570 (Reduce RTM Settlement Timeline to Operating Day Plus Five): Impacts on notices when EPS meter data are required on the same business day to support settlements and non-business day coverage (D. Tucker and P. Vinton) EPS Metering Facilities Repairs If an EPS Metering Facility requires repairs to ensure that it operates in accordance with the requirements of this Section, then the TSP or DSP shall immediately notify ERCOT of the need for repairing such Metering Facility. If, however, operating conditions are such that it is not possible for the Transmission and/or Distribution Service Provider (TDSP) to notify ERCOT of the need for repairs, then the TDSP may make the necessary repairs and then notify ERCOT of the repairs prior to the end of the next Business Day.

(a) Where no Back-up Meter exists or Back-up Meter data is unavailable, the TSP or DSP shall ensure that the metering point is repaired and operational within 12 hours of problem detection; [NPRR570: Pending system implementation, replace paragraph (a) above with the following on May 1, 2014 unless the ERCOT Board affirmatively votes to delay implementation of this paragraph to a later date or condition:] (a) Where no Back-up Meter exists or Back-up Meter data is unavailable, the TSP or DSP shall ensure that the metering point is repaired and operational within 12 hours of problem detection. ERCOT may, at its discretion, reduce the repair timeline from twelve to six hours if the meter data is required for Real-Time Market (RTM) Settlements on the same day.

C. Continuation of NPRR-570 discussion and overview of proposed SMOGRR

D.Follow-up discussion on CCVT 5-year re-certification (T. Davis/H. Perez/D. Maul) * Out of 207 units of CCVTs used as EPS metering PTs in the ERCOT region, only 6 units had the original test report when it first came out of the factory and had the “as-found accuracy” and “as-left accuracy” test data from the re-certification test provided to ERCOT. * This is a small sample and may not be useful to arrive at a conclusion on whether the CCVTs retain its metering accuracy over time or not. * Ideally, a more reasonable sample rate would be 36% of the total number of CCVTs

E. Follow-up discussion on Parallel CT clarification per SMOG (e) (H. Perez) SMOG (e) Paralleling of Current Transformers – Connected burden Paralleling of current transformers is not recommended. However, when it is necessary, the following requirements apply. (e)Each current transformer must be capable of supporting n times the connected burden within the accuracy class of the transformers, where n = number of current transformers in parallel.

Open item questions regarding paralleling of CTs: i.How to verify individual impedance on each conductor and common impedance? ii.Is common burden shared equally between all parallel CTs? iii. Should maximum current (at rating factor) be utilized in calculating total burden on each CT in case of flow thru scenarios (eg. Breaker-and-half scheme)? iv. What is the impact if CT primary is shorted? v. What was the result of the lab test conducted by CPS regarding paralleling of CTs?

F.) Follow-up discussion on Loss of potential per SMOG define specific threshold voltage (C. Wang) ERCOT presented loss of potential issues and proposed that partial loss of potential (other then zero) shall be logged by EPS meters. A survey was sent out to TDSPs to determine if there is a common value of abnormal voltage setting being used. The survey came back with different results. In the absence of a common value of under-voltage setting, a proposal to set the meters for loss of potential alarm during the next annual meter testing is hereby being presented: “If the measured voltage falls below 75% of the meter’s nominal supply voltage (e.g., the standard rms voltage measured at the test switch) for 4 seconds or more, this shall trigger a “loss of potential event” which will be recorded and sent to ERCOT’s MV-90 system.”

G.) EPS metering sites with provisionally approved status On 10/16/12 there were 57 Sites that are still Provisionally Approved 43 of the 57 sites - ERCOT has not received final “as-built” drawings 7 of the 57 sites – covered by Temporary Exemption The remaining 7 are due to phase angle and burden test information As of 10/7/13 there are 43 Sites that are Provisionally Approved 26 of the 57 sites – status has changed to Approved 12 sites were added to the Provisionally Approved List 26 of the 44 sites - ERCOT has not received final “as-built” drawings 5 of the 44 sites – covered by Temporary Exemption The remaining 12 are due to phase angle and burden test information

EPS metering sites with provisionally approved status SMOG Section (h) – Note: If a redline version is supplied, the final “as-built” drawings shall be submitted within 45 days of the submittal of the Site Approval Request Package. –4 are dated prior to 2005 –14 are date between –8 are dated between

EPS metering sites with provisionally approved status ERCOT is providing information to TDSP to resolve as many provisionally approved sites as possible. –First round of s sent on –Presentation at MWG Meeting –Second round of s sent on –Presentation at MWG Meeting –Follow-up

EPS metering sites with provisionally approved status Final “As-Built” Drawing criteria: –Should not contain hand writing updates, markings, corrections or comments (except signature) –Should have revision number/letter and date greater/later than what is on the “red-lined” drawings that are on file –If drawing number changes or revisions numbers are listed on Site Certification, then an updated/corrected Site Certification form is required

H.) Follow-up discussion on TDSP’s submission of nameplate photos of newly-installed instrument transformers - CTs & VTs (H. Perez) Benefits of submitting photos of nameplate of newly-installed instrument transformers (picture taken while de-energized): 1.) Nameplate shows important data including exact specifications and windings of the instrument transformers and others (including its non-PCB insulating oil) 2.) Visual record handy. No need to dispatch personnel to the substation when verifying exact specifications of the instrument transformers. The information is already captured on the nameplate 3.) Safety. Taking pictures of instrument transformers’ nameplate, which sometimes put personnel in close proximity to energized high voltage busses, can now be avoided

Proposal to incorporate nameplate photos on future initial site certification document submittals - Nameplate photos of newly- installed instrument transformers For new sites, nameplate photos will be submitted together with the initial site certification For existing site, nameplate photos of instrument transformers that are replaced can also be submitted with the site certification For other instrument transformers, photos can be taken during a planned outage

Nameplate photos of newly-installed instrument transformers

I. New or other business items (D. DiSanto)

J. Meeting wrap-up (D. DiSanto)

Questions?