CITY COUNCIL AGENDA ITEM
ACTION REQUESTED:
title
Approve the award of Cooperative Procurement 25-120, 138kV Hitachi Circuit Breakers, to Wesco, Inc. for an amount not to exceed $2,627,166
body
body
DEPARTMENT: Electric Utility
SUBMITTED BY: Brian Groth, Director
BOARD/COMMISSION REVIEW:
N/A
BACKGROUND:
A major component of the Electric Utility (Utility) transmission system is 138kV circuit breakers. The City has 36 breakers that are large, complex devices located inside ten of the substations. Their main purpose is to trip/open under the control of a relay to interrupt power flow when there is a system problem, or when directed by a System Controller to isolate parts of the system to make it safe for crews to perform work.
The oldest circuit breakers in use are outdated models from ABB from the 1980s. Meadows Substation and Modaff Substation are equipped with these obsolete ABB-type HPL and HLR breakers. In addition, the City operates 18 obsolete Siemens breakers, specifically the Siemens TCP style. These 18 TCP breakers, which were installed in 1990, have surpassed their planned 30-year lifespan. Springbrook Substation and Route 59 Substation each have three of these Siemens TCP breakers.
Sourcing both qualified technicians and replacement parts for the maintenance of these circuit breakers has become increasingly difficult. In the event of a catastrophic failure, the Utility does not have a spare breaker available to restore the system, which could result in large portions of the service territory being on its last contingency. This increases the risk of prolonged power outages if a second issue arises while the breaker is out of service.
To maintain the reliability of the 138kV transmission system, modernization of both the ABB and Siemens breakers is essential.
DISCUSSION:
Utility Engineering, in collaboration with consultants Sargent and Lundy, developed technical specifications for a next-generation breaker to replace the Siemens TCP and ABB...
Click here for full text