Hurley-Natomas-Elverta Line Relay Upgrade

CLIENT: Sacramento Municipal Utility District
LOCATION: Sacramento, CA

IEC successfully completed the Hurley and Elverta 230 kV Line Relay Upgrade for the SMUD Distribution Department. IEC provided the detailed design to remove and replace all the existing directional distance electro-mechanical relays and carrier system with new micro-processor protective relays. The relay replacement was required to support the installation of the new 230 kV Natomas Substation located between Hurley and Elverta Substations. The existing 230 kV transmission line was intercepted between Hurley and Elverta Substations and rerouted into the new 230 kV Natomas Substation. In doing this, SMUD created a 230 kV transmission line from Hurley to Natomas and from Natomas to Elverta. IEC was contracted to remove the existing directional distance electro-relays at Hurley and Elverta Substations and replace those relays to match and coordinate with the new micro-processor protective relays at Natomas Substation. In addition, this design required interfacing the new protective relaying into the existing substation systems, including: oscillograph, annunciation, telemetering, communication, transfer trips, and bus differential protective relaying scheme. The modification also included the complete retrofit of the new protective relay panel on the existing substation duplex panels.

Our fast-track engineering efforts allowed the construction phase of the project to remain on schedule without any delay for the District. IEC received commendations for the quality and timeliness of our work from SMUD Project Engineers and for our “cooperative, enthusiastic, and professional approach.”