06-24-2019 BPU RPT 07 - Laserfiche WebLink

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W A T E R E N E R G Y T I F F id& P U B L I C U T I L I T I E S BOARD OF PUBLIC UTILITIES RIVERSIDE PUBLIC UTILITIES Board Memorandum SUBJECT: EMERGENCY WORK FOR BREAKER REPLACEMENTS $143,920 ISSUE: DATE: JUNE 24, 2019 ITEM NO: 7 LA COLINA AND RIVERSIDE SUBSTATION CIRCUIT — WORK ORDER NO. 1832655 IN THE AMOUNT OF Approve Work Order No. 1832655 in the amount of $143,920, in accordance with the City of Riverside Charter Article XII, section 1202(2) (b), for emergency work completed due to circuit breaker failure at La Colina and Riverside Substation. RECOMMENDATION: That the Board of Public Utilities approve Work Order No. 1832655 in the amount of $143,920, in accordance with the City of Riverside Charter Article XI I, section 1202(2) (b), for emergency work completed due to circuit breaker failure at La Colina and Riverside Substation. BACKGROUND: High voltage circuit breakers (circuit breakers) are used to interrupt electrical faults and isolate sections of the electric system. Circuit breakers are essential for the electrical protection of surrounding equipment, the safety of personnel, and the reliability of the electric system. The average service life of circuit breakers filled with oil is between 30-40 years. Several of these circuit breakers within Riverside Public Utilities (RPU) electric system have exceeded or are reaching the end of their design life. The age of the circuit breaker is a significant factor in the electric system reliability, safety, and maintenance costs. The interrupting capabilities experience a decline as circuit breakers age. Age also reduces the ability of the circuit breaker to handle electrical and mechanical stresses encountered during electrical faults. RPU has experienced the in-service failure of two 69kV oil -filled circuit breakers, one at Riverside Substation and the other one at La Colina Substation.