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High Voltage Substation

Case Studies

High Voltage – Fast Track Power Case Studies

High Voltage Emergency Power Response

United States:

A new merchant power plant was attempting to go online in time to meet the summer peak demand when their new generator step-up transformer failed while energizing the switchyard. Equisales responded by providing a 265 MVA rental transformer, allowing its customer to meet their original schedule and be back in production by the start of the peak season.

Savings to customer: > $5 million in penalties and lost revenues.


A generation plant in Pennsylvania experienced a failure of a 95MVA 115kV generator step-up transformer. Equisales had a 90 MVA replacement unit available, but transportation regulations necessitated a two-week delivery time. As our client wanted to maintain production during those two weeks, we shipped a temporary unit from stock in Houston and delivered the unit to our customer’s site within five days of their order. Power operations resumed within forty-eight hours of arrival. When the 90MVA arrived on the site, Equisales decommissioned the 95MVA transformer, then completely assembled and installed the 90MVA transformer, including all buss work, cabling, and interconnections, in less than thirty-six hours.

Savings to customer: > $5 million in penalties and lost revenue.


A new merchant power plant lost both of its generator step-up (GSU) transformers within a period of five weeks. In each instance, the client elected to charter the Antonov to fly in the transformer, Equisales’ mobile vacuum units and service technicians. Equisales had the two transformers (a 85MVA and a 93 MVA) shipped from its stock, installed, and commissioned the units in less than 10 days from notice to proceed.

Savings to customer: > $5 million in penalties and lost revenue.

High Voltage Equipment Rental


An Exxon refinery in Texas had a transformer failure. After evaluating the purchase options versus repair options, Exxon elected to repair the transformer. Equisales removed their transformer and provided and installed a rental 25 MVA transformer in series with a 2500 KVA voltage regulator for a nine-month period. Once Equisales repaired the transformer, we removed the rental transformer and re-installed the repaired transformer. We also provided Exxon with complete high voltage sub-station and switch-yard on a rental basis. This included not only the transformer, but also the high voltage breakers, disconnect switches, metering equipment, buss connectors and other protective devices. In the summer of 2001, Equisales simultaneously supported two temporary generation sites of 100 MW each, with complete skid-mounted sub-stations on a rental basis. Each site contained two generator step-up transformers, plus the supporting equipment (distribution skids, disconnect switches, high voltage breakers and auxiliary transformers) to transform the power to the grid voltage of 138 kV and 230 kV, respectively. Both sites were simultaneously delivered and installed in 4 to 6 weeks.

Savings to customer: approximately $10 million.

High Voltage EPC Sub-stations and Switchyards


A large international private power company needed assist once with their high voltage requirements for a new 345 kV, 1000 MW power plant, approached Equisales. Two other major international engineering and construction firms had previously been contracted to provide engineering services for the project, but had not been able to develop the high voltage system in time to meet the client’s required startup date. After a thorough project status review, Equisales was awarded the EPC contract and took over the engineering and erection of both the sub-station and the switchyard for the 345 kV system, completing both in time to meet the startup date.


A large turbine OEM packager signed a turnkey 45MW power plant contract two days before Christmas, 2002. As the project site was located in Central America and the contract commitment required commercial operation within 60 days, with steep penalties for late delivery, the customer turned to Equisales for engineering, procurement, and construction of the 138kV sub-station. All equipment was loaded and departed the Port of Houston by January 10th, and Equisales delivered the equipment on time and finished the construction and commissioning at the site in 19 days.


An Independent Power Producer built two 550 MW projects. One at 138 kV the other at 345 kV. Equisales took on the complete EPC role (engineering, procurement, and construction) role completing each site more than 30 days early (project duration 5 months per 275 MW block), insuring that the plants were on time for the peak summer load.


Project Location – 50km south of Nequen Argentina
Scope 500kv substation, full turnkey supply of equipment, engineering and installation
Time to complete – January 2015 to December 2015
Substation supplied in support of GE LMS100 100mw gas turbine