CONDITIONS IMPACTING TRANSMISSION CAPABILITY

CONDITIONS IMPACTING TRANSMISSION*

* The Conditions Impacting Transmission page is manually updated on an as needed basis to post “Special Notices” for conditions within the PJM footprint that may impact the capability to deliver power across the transmission system. Posting will remain on this page for a period of one year.

Special Notices:

Brandon Shores – Riverside (2344 & 2345) 230kV Circuit Status Update

Updated 6/1/2009

Baltimore Gas & Electric (BGE) is continuing to analyze the operation of the Brandon Shores to Riverside 2344 and 2345 circuits.

On April 20, BGE took an emergency outage on 2344 to address concerns with the condition of the oil in these oil-filled pipe cables that are underwater in the Baltimore Harbor. Gas testing confirmed a high level of dissolved gas indicative of arcing, and additional samples and tests confirm that initial analysis. To pinpoint the problem, BGE performed an outage to “degasify” the oil in the cables. BGE has reenergized the cables on 2344 and is monitoring the oil through an organized procedure in hopes to clearly identify the location of the arcing. BGE expects to perform a similar procedure on the 2345 circuit in September. BGE will take an outage on 2345 and “degasify” the oil in those cables. When 2345 returns to service BGE will operate (estimated from September 16 to October 5) without circulating the oil in the cable with a temporary rating of 850 MVA normal and emergency rating is limited by the transmission circuit at 1153 MVA (at 95˚ F temperature set).

Based upon the analysis results to date, BGE expects that both 2344 and 2345 will be operated in their normal configuration at full ratings through the summer. BGE plans to continue to perform additional testing. When the source of the arcing is clearly identified, BGE will determine the next steps to resolve the problem.

The following BGE emergency outages are submitted via eDart:

Start Date	Stop Date	eDart #	Transmission Facility Outage
6/1/09 @ 05:30	6/1/09 @ 21:00	374454	Brandon Shores – Riverside 230kV (2344) Circuit
9/1/09 @ 05:30	9/15/09 @ 23:00	374455	Brandon Shores – Riverside 230kV (2345) Circuit
10/06/09 @ 05:30	10/06/09 @ 21:00	374456	Brandon Shores – Riverside 230kV (2345) Circuit

Bath County Pumped Hydro SPS In-Service Date Notification - April 26, 2009

Updated 4/24/2009

The approved operational in-service date for the new Bath County Special Protection Scheme is now Sunday 4/26/2009 at 00:01hrs.

Updated 4/21/2009

The Bath County SPS due to go into effect tonight 4/21/09 has been postponed for approximately one week. This is primarily due to recent interpretations of NERC maintenance criteria that need to be addressed prior to implementation. A subsequent posting will be made with a new implementation date and time.

Updated 4/20/2009

The Bath County Special Protection Scheme (SPS) will be available for use in Real Time Operations and the Day Ahead Market on 4/22/09 @0001hrs.

Updated 1/23/2009

The in service date for the Bath County Special Protection Scheme (SPS) is targeted for April 22, 2009. The SPS is designed to control loading on the Cloverdale - Lexington 500kV facility when Bath County is pumping. The SPS scheme will immediately trip 1 or 2 pumps when a transmission contingency causes overloading of the 500 kV line between AEP Cloverdale Substation and Dominion Transmission Lexington Substation. The focus of the SPS is on protection of two AEP autotransformer banks at Cloverdale from sustained operation above emergency rating in this circumstance. The SPS has received Regional Reliability Organization approval and has been presented at the PJM Committee Structure as outlined in the PJM Transmission Operations Manual (M03), Section 1 - Transmission Operations Requirements. The scheme was presented to the PJM Committee structure as follows: PJM System Operations Subcommittee 9/10/08, PJM Planning Committee 9/17/08, PJM Operating Committee 9/16/08, PJM Market Implementation Committee 9/11/08, and PJM Markets and Reliability Committee 9/24/08.

PJM – NYISO Interface Capability

Updated 3/13/09

Updated 3/17/09

The PJM-NYISO Interface Capability will be limited by NYISO planned outages on March 24, 2009 - April 17, 2009 (refer to the NYISO OASIS for outages scheduled and corresponding TTC reduction information).

AEP Cook Transformer Outage Information

Updated 2/17/2009

This notification is to provide information on the impact of a transmission outage, in addition to other expected system conditions, on the AEP-MECS interface in April 2009. Starting on April 1 2009, AEP will be taking an outage of the Cook 765/345 kV transformer and the Cook 345 kV bus for an upgrade under PJM eDart #233128. The bus outage sets up a potential contingency where the loss of the Cook-Benton Harbor 345 kV line will also remove the Cook-Palisades 345 kV from service. The outage was jointly studied by PJM and MISO for reliability and for determining the power transfer capability through the AEP-MECS interface.

The study concluded that due to first contingency thermal or voltage violation criteria, the power transfer through the AEP-MECS interface may be restricted to approximately 2200 MW. To maintain reliability, the flow on the AEP-MECS interface and on the Argenta-Twin Branch 345 kV tie line will be limited in order to not exceed first contingency thermal or voltage limits for the duration of the outage. In addition, the study identified critical generators and necessary capacity in the region to facilitate the outage.

PJM and MISO Planning & Operations will continue to assess other planned and unplanned outages in the region for impact.

Rating Changes to AP 500 kV Facilities

Updated 12/16/08

During a recent review by Allegheny Power (AP) of their thermal ratings, an error was identified in a database table of component ratings for a 2 conductor bundle of 2032.1 ACSR. A review of historical databases identified that the error had occurred when AP joined PJM. At that time, the emergency ratings changed from 6 hours to 4 hours, and also the quantity and range of ambient operating temperature sets was revised. The error affected the 4-hour emergency and Load Dump ratings for 2-2032.1 ACSR.

As a result of this review, effective 2/2/2009, AP will be changing the ratings of some of their 500 kV facilities. These rating changes can be viewed at:

http://www.pjm.com/markets-and-operations/etools/oasis/~/media/etools/oasis/system-information/20090202-ap-500-kv-ratings-changes.ashx

PJM – NYISO Interface Capability

Updated 10/27/08

The PJM-NYISO Interface Capability will be limited by NYISO planned outages (refer to NYISO OASIS for outage schedule information). The TTC will be reduced from 2500MW to 1200MW for the duration of their scheduled work.

Bedington – Black Oak interface disabled

Updated 9/29/08

During the scheduled outage of the Bedington- Doubs 500kV line (eDart #207711), the Bedington-Black Oak Transfer Interface will be disabled.

New Transformer at Conastone (BC)

Updated 8/26/08

Upon completion of eDART ticket # 213462 (scheduled from 8/23/2008 thru 8/27/2008), the new ‘500-4’ 500/230 kV transformer will be in-service. The existing ‘500-2’ 500/230 kV transformer will then be opened and placed on hot-standby to eliminate over-dutied breaker concerns under eDart #348312. The 500-2 transformer will then be removed under eDART ticket #235907 (scheduled to begin 9/3/2008). The 500-2 transformer will remain out of service under eDart #348382 until replaced in Spring of 2009.

Mt Storm 500kV Circuit Breaker Monitoring

Updated 7/9/08

On 7/1/2008, the PJM EMS model was enhanced to allow the monitoring of the individual Mt Storm 500kV single Circuit Breakers for actual and contingency overloads. Prior to the enhancement, the Mt Storm 500kV line flows were used as proxies to monitor for the 500kV Circuit Breaker limitations. As a result of this new enhancement, Real Time constraints have occurred on the Mt Storm “G2T550” 500kV breaker for the loss of the Mt Storm RSS2 500/35kV Station Service Transformer with failure of the sectionalizing scheme to reclose the Mt Storm #1 500kV bus. As indicated in PJM Manual M-03, all facilities are screened against their appropriate Load Dump ratings for a simulated failure of a sectionalizing scheme.

AP South Reactive Transfer Interface Redefinition

Updated 7/8/08

PJM has performed an evaluation of the current definition of the AP South Interface. The analysis indicated that certain units in western Dominion and southeastern AEP are currently considered lower help units when raising these units actually increase transfer margins and help voltages at monitored buses. PJM is recommending that the interface be redefined to include the Mt Storm - Valley 500kV line in addition to the Mt. Storm - Doubs and Meadowbrook - Greenland Gap 500kV facilities. Redefining the interface will send the correct pricing signals to generators and increase operational and market efficiency. PJM will be communicating the change at the July SOS, OC and MIC meetings with a planned implementation of September 1, 2008

FUTURE ORCHARD/NEW FREEDOM/EAST WINDSOR AREA RECONFIGURATION NOTICE

Updated 10/21/08

At the start of outage request #232608 this Fall, the existing Orchard-East Windsor “5038” 500kV line will be permanently cut and will no longer exist in the current configuration.

As of 10/15/08, the Orchard – East Windsor ‘5038’ 500 kV line no longer exists, and outages for this line will no longer be submitted in OASIS. The new configuration will consist of the Orchard-New Freedom “5039” 500kV line and the New Freedom-East Windsor “5038” 500kV line. Refer to outage tickets #248126 and #248127, which indicate the projected in-service dates for the new 5038 and 5039 lines respectively.

COMED 345 KV LINE OUTAGES DUE TO STORMS

Updated 7/7/08

The East Frankfort – Crete 345kV and East Frankfort – University Park 345kV lines returned to service on 6/27/08.

Updated 06/17/08

Recent forced outages in the ComEd transmission system coupled with heavy West – East transfers have resulted in increased congestion in the ComEd and NIPSCO systems. With the common tower lines of East Frankfort – Crete 345kV and East Frankfort – University Park 345kV forced out of service due to storm damage, during heavy transfers from West – East through ComEd, thermal constraints have been encountered in ComEd & NIPSCO, for which off-cost operations have been required.

BGE RATINGS CHANGES

Updated 6/18/08

The information previously posted here has been moved and can be linked directly from the http://www.pjm.com/markets-and-operations/etools/oasis/system-information/~/media/etools/oasis/20080501-bge-ratings-changes-for-june-1-2008.ashx page. This was moved due to size.

EAST WINDSOR TRANSFORMER

Updated 6/18/08

The East Windsor #1 500/230kV transformer was returned to service on 5/21/08

Update – May 12, 2008

The East Windsor #1 500/230 kV transformer is currently expected to return to service on 6/1/2008.

On Friday, March 3, 2006, the East Windsor #1 500/230kV transformer failed and is expected to have an extended outage. For this summer's forecasted conditions, the outage of the second East Windsor 500/230kV transformer or the nearby Smithburg 500/230kV transformer, should not have a major impact on system reliability.

EAST TOWANDA SECTIONALIZING SCHEME

Update 2/28/08
Work was completed under eDART #237768 and the East Towanda #3 transformer was returned to service on 02/28 @ 2128. At that time the ~50% increase in ratings for all temperature sets on the transformer as effective. An additional transmission outage will be required to return the Transformer to its per-July 2007 ratings, but that outage is not presently scheduled.

Update 2/19/08
Due to a revised work plan, FE East has submitted eDart ticket #237768 scheduled for 2/25-2/29. This outage replaces eDart ticket #230048, which has now been ‘cancelled’. Upon completion of eDart #237768, the East Towanda #3 transformer ratings will increase as described below in the 2/11/08 update.

Update 2/11/08
Upon completion of eDart ticket #230048, the ratings of the East Towanda #3 230/115kV transformer will increase ~50% for all temperature sets. However, an additional transmission outage will be required to return the Transformer to its pre-July 2007 ratings. This second outage has not yet been scheduled.

Update 1/15/07
On Thursday 1/10/07, the Operating Committee waived the 90-Day waiting period defined in PJM Manual M-03 and approved the immediate use of the East Towanda Automatic Sectionalizing scheme in Real Time Operations. The Sectionalizing scheme will restore the East Towanda 230kV bus and East Towanda - North Meshoppen 230kV line, following a fault on the East Towanda #4 transformer. This contingency and sectionalizing scheme will be screened in the PJM EMS. Any resulting overloads will be controlled to their Long Term Emergency rating. Also, in accordance with PJM Manual M-03, PJM will continue to screen for the loss of the East Towanda #4 transformer with the Sectionalizing scheme failing. All subsequent overloads will be controlled to their Load Dump rating.

In early July of 2007, FE East discovered the East Towanda #3 transformer was more limited by a low side bus conductor than the transformer itself. On July 19, 2007, FE East submitted a rating reduction of the East Towanda #3 transformer to PJM based upon the low side bus conductor limit. This rating reduction was immediately entered into the PJM EMS system and controlled to in Real Time Operations. This derate will remain in effect until the low side bus conductor can be replaced. The tentative date for this replacement is late March or early April. Any updates to this time frame will be posted to this webpage.

TRANSMISSION OUTAGE CHANGES REPORT

The previously posted “Outages Impacting ATC” posting has been removed from this page. A list of Outage changes impacting the Monthly ATC posting can be found at the following link: “ftp://ftp.pjm.com/pub/oasis/outage_changes_report.txt”. This file can also be accessed from the “ATC Information” section of the PJM OASIS.