December 10, 2009
Council Approves $225,000 Upgrade to Electrical System
With only one way in and out, the Memphis municipal electrical system rests precariously on the back of one substation. If that substation were to fail, the city would be forced to generate power until it could be repaired or replaced.
In an effort to eliminate that bottleneck and also upgrade the systems performance, the Memphis City Council voted 3-0 on December 3rd to proceed with the purchase of equipment for a second substation.
Representatives from BHMG Engineering Services met with the council for bid openings for components for the upgrade.
A bid of $124,714 from ABB Corporation of Swansea, IL, was accepted for the main component, the power transformer. Other bids were for $141,600 and $210,717 from Solomon Corp. and T&R Electric.
T&R Electric of Colman, SD, was awarded the contract for three step voltage regulators to be used in the new substation. The cost was $21,375. The council elected to work with refurbished regulators, cutting the cost roughly in half. The move was made possible because the city maintains a back-up regulator that can be used in either substation.
Three 15.5 kV 1200 ampere outdoor circuit breakers will be purchased from Square D – Schneider Electric at a cost of $63,900.
The final components for the new substation will be purchased from Weisler and Associates of Chesterfield, MO. A 48-volt DC battery supply system for the new substation will cost $16,278.
With component delivery dates varying from 60 days to 16 weeks, the engineers highlighted the importance of creating the new substation. If a failure occurred in the current substation, the city could be forced to generate power for a similar time period while awaiting replacement parts.
While the key for the decision was the creation of a true back-up for the city’s electrical system, engineer Dave Stephens, noted that the newer transformer in the substation will have lower load loss ratios than the city’s existing system. Over time as more of the city’s service is transferred over to the new substation, this upgrade will produce cost savings for the utility system.
With the purchase of the electrical components complete, the city will now seek bids for the substation structures. Bids will be due December 30th and will be reviewed at the January 7th council meeting.