May 24, 1972 Consolidated Edison Co... New York City...... Transient loss Branch 3 .45. burg-Ramapo 500-kilovolt CARVA Pool includes: Carolina Power & Light Co., Duke Power Co., South Carolna Electric & Gas Co., and Virginia Electric & Power Co. CARVA Pool includes: Carolina Power & Light Co., Duke Power Co., South Carolina Electric & Gas Co., and Virginia Electric & Power Co. › Manual-Approximately 9 hours; authomatic-2.5 hours; mornings-1.5 hours. APPENDIX C FEDERAL POWER COMMISSION-BUREAU OF POWER SUMMARY OF JULY 1972 NEW YORK CITY POWER PROBLEMS The Consolidated Edison Company of New York has reported through July 26, 1972 three instances of customer service interruptions or curtailments necessitated by low-voltage distribution system inadequacies or equipment failures. The first, a relatively minor effect, occurred on July 12, 1972 when a five percent voltage reduction for approximately four hours was used on certain critically loaded distribution cable feeders to keep cable loadings within safe limits. Of more serious consequence, was the interruption to approximately 100,000 metered customers (100 megawatts estimated load) in the Bay Ridge area of Brooklyn at 9:45 p.m., on July 17 when eight of twelve 27-kilovolt cables failed, necessitating the removal from service of the remaining four to avoid their being damaged. All service was restored 13 hours and 19 minutes later. On July 24 at 10:30 a.m., and extending over a period of 19 hours and 17 minutes, about 185,000 metered customers (150 megawatts estimated load) were interrupted in the Richmond Hill area of Queens when seven 27-kilovolt cable feeders failed. Although near the interrupted area, Kennedy Airport was not affected. It is estimated that an average of approximately 21⁄2 persons per metered customer were affected by these interruptions. In both the July 17 and July 24 incidents, the cable failures were attributed basically to gradual deterioration resulting from moisture and residual salt from previous snow removal applications. Such failures are not uncommon but do not always occur in such combinations that they create serious problems as have been experienced this summer. Bulk power system inadequacies have caused the Company to initiate voltage reduction measures to maintain operating reserve margin levels or limit loadings on transmission lines. Such voltage reductions, none more than five percent, were initiated on July 17 (before the distribution system trouble), July 18 and July 20. On July 17 loaded transmission lines caused the reduction to be effected. The July 18 and July 20 voltage reductions were to maintain operating margin levels on the generating equipment. Do... July 27, 1970 Consolidated Edison Co...... New York, N.Y...... Combination of heavy New England Power Ex loads and large amounts New England.. do.. change. 3 4. 5 5. 3-5 8. Consolidated Edison Co...... New York, N.Y...... Voltage reduction instituted Date Utility or pool Feb. 5, 1971 May 19, 1971 June 7, 1971 do. do. Long Island Lighting Co... Long Island, N.Y.... Heavy loads due to high Portions of North All of New England New York, NY. surrounding area. pool. Sections of Brook lyn, Bronx, and New York, N.Y.......... All of New England.. Generator outages.... To prevent possible overloading of incoming tielines. Forced outage of Ravenswood Unit No. 3. Transmission line fault.. do. Heavy summer loads. 2,250 megawatts. Stepup transformer explo sion. Combination of heavy loads and large amounts of unavailable capacity. do do. do New York State. do. do New England. do. New York State. do. New England.. do. Cleveland, Ohio..... New York State..... New England. Pennsylvania-New New York State. Pennsylvania-New Jersey-Maryland. Trouble at the 577-megawatt East Lake plant. Combination of heavy loads and large amounts of unavailable capacity. .do.. do do. do Outage of the 800-megawatt. Dresden Unit No. 2. Combination of heavy loads and large amounts of unavailable capacity. do Voltage reduction instituted to assist the New York Power Pool. and large amounts of unavailable capacity. Combination of heavy loads New England....... Forced outage of the 662 do. 3,400 megawatts of generating. May 24, 1972 Consolidated Edison Co...... New York City...... Transient loss Branch 3 .45. burg-Ramapo 500-kilovolt CARVA Pool includes: Carolina Power & Light Co., Duke Power Co., South Carolna Electric & Gas Co., and Virginia Electric & Power Co. CARVA Pool includes: Carolina Power & Light Co., Duke Power Co., South Carolina Electric & Gas Co., and Virginia Electric & Power Co. Manual-Approximately 9 hours; authomatic-2.5 hours; mornings-1.5 hours. APPENDIX C FEDERAL POWER COMMISSION-BUREAU OF POWER SUMMARY OF JULY 1972 NEW YORK CITY POWER PROBLEMS The Consolidated Edison Company of New York has reported through July 26, 1972 three instances of customer service interruptions or curtailments necessitated by low-voltage distribution system inadequacies or equipment failures. The first, a relatively minor effect, occurred on July 12, 1972 when a five percent voltage reduction for approximately four hours was used on certain critically loaded distribution cable feeders to keep cable loadings within safe limits. Of more serious consequence, was the interruption to approximately 100,000 metered customers (100 megawatts estimated load) in the Bay Ridge area of Brooklyn at 9:45 p.m., on July 17 when eight of twelve 27-kilovolt cables failed, necessitating the removal from service of the remaining four to avoid their being damaged. All service was restored 13 hours and 19 minutes later. On July 24 at 10:30 a.m., and extending over a period of 19 hours and 17 minutes, about 185,000 metered customers (150 megawatts estimated load) were interrupted in the Richmond Hill area of Queens when seven 27-kilovolt cable feeders failed. Although near the interrupted area, Kennedy Airport was not affected. It is estimated that an average of approximately 21⁄2 persons per metered customer were affected by these interruptions. In both the July 17 and July 24 incidents, the cable failures were attributed basically to gradual deterioration resulting from moisture and residual salt from previous snow removal applications. Such failures are not uncommon but do not always occur in such combinations that they create serious problems as have been experienced this summer. Bulk power system inadequacies have caused the Company to initiate voltage reduction measures to maintain operating reserve margin levels or limit loadings on transmission lines. Such voltage reductions, none more than five percent, were initiated on July 17 (before the distribution system trouble), July 18 and July 20. On July 17 loaded transmission lines caused the reduction to be effected. The July 18 and July 20 voltage reductions were to maintain operating margin levels on the generating equipment. |