A routine maintenance program at the Lang Street Substation has short-circuited a potential power outage, but its efficiency is also saddling Cleveland Utilities with an unplanned pay-me-now or pay-me-later expense totaling about $86,000.
On a motion by Cleveland Mayor Tom Rowland and second by Joe Cate, the Cleveland Board of Public Utilities voted 5-0 Monday to authorize CU to go ahead and spend the money now to prevent outage headaches later.
Technically, the vote became a formality because CU President and CEO Ken Webb had already signed the purchase order because of the repair’s emergency status.
During the board session in CU’s Tom Wheeler Training Center, Webb explained the urgency in going ahead and signing the emergency order because of the long delivery time required by all three vendors who submitted bids for 29 new bushing insulators.
Webb pointed out such predicaments don’t arise often, but when they do the public utility makes every effort to place the expenditures on a board agenda as soon as possible.
Bart Borden, vice president of CU’s Electric Division, briefed the board on the maintenance testing that revealed the Lang Street Substation was in danger of a potential outage, and a similar fate could soon befall the East Cleveland Substation because it operates with some of the same types of equipment.
“On June 13, during routine testing, Cleveland Utilities discovered indications that the bushing insulators were failing on the Lang Street Substation power transformer,” Borden explained. “Three of the power transformer insulators were replaced with new insulators from a refurbisher’s stock that we were fortunate to find.”
According to Borden, a bushing insulator “... insulates high voltage from the transformer tank.” He further described the piece of equipment as an “... external connection to the internal windings that insulate to the transformer tank.”
The new bushing insulators were purchased June 18 and installed on June 23 immediately after they were received. The Lang Street Substation, which had been shut down once tests revealed the bushing insulator failures, was placed back in service June 24.
However, fixing one problem — the Lang Street Substation — gave CU crews reason to believe a similar fate could await the East Cleveland Substation.
“Since East Cleveland [161/69 kV] Substation has the same bushing insulators in service, we requested Liberty Power (a contractor) to perform tests on the spare power transformer bushing insulators,” Borden explained. “The test results indicated all the bushings were failing. We immediately began the process of attempting to locate bushing insulators in stock, and have been unable to do so.”
Subsequently, last Friday CU placed an order with Solomon Corporation for the replacement of all 29 bushing insulators which includes spares for each voltage that will be placed in storage, Borden explained. That’s the good news. The bad news is the vendor quoted delivery time of 16 to 18 weeks from receipt of the order; and that’s why Webb made the decision to sign off on the purchase order.
Borden told board members CU is working to expedite shipment.
The Solomon bid for the bushing insulators totaled $85,973; this was the low bid, both in price and shipment time required.
Two other bids were received, including Pcore Electric at $92,487 with delivery in 20 to 22 weeks, and ABB at $169,213 with delivery of 26 weeks.
With the Lang Street Substation now up and running, Cleveland Utilities crews shut down the East Cleveland Substation on Monday “... so testing could be conducted on the three power transformers in service,” Borden told the board. The East Cleveland Substation load was switched to CU’s South Cleveland Substation, Borden said.
“The test results [from East Cleveland] will determine if we are able to re-energize the power transformers or if South Cleveland will continue to serve our load and a portion of the load placed on TVA’s East Cleveland power transformers, until the replacement bushing insulators are installed,” the Electric Division leader explained.
He pointed out the bushing insulator problems at the Lang Street nor the East Cleveland substations had nothing to do with last week’s extensive power outage affecting the downtown area and several traffic signals for about 45 minutes. That issue involved an insulator located near 20th Street and King Edward Avenue S.E. Some 4,000 customers were affected.
Borden said the Electric Division had budgeted for certain substation and equipment projects in Fiscal Year 2015; however, the urgency of the Lang Street and East Cleveland substation issues prompted CU leaders to launch into their repairs immediately.
“We have not lost a bushing insulator [yet],” Borden told board members. But, maintenance tests have revealed the insulators are failing, he added.
Borden said crews were busy Monday testing the integrity of equipment at the East Cleveland Substation.
Three other utility board members joined Rowland and Cate in authorizing the emergency expenditures that had been signed by Webb: Aubrey Ector, chairman; Eddie Cartwright, vice chairman; and Chari Buckner.