Substation Repair Project for Municipality In Florida

Power class substation transformer southern florida municipal utility

In this case, Solomon Corporation employees leveraged their considerable experience and expertise to repair a power-class substation transformer for a municipal utility in Southern Florida. Solomon Corporation managed the complete project, including transportation, inspection, redesign, manufacturing, testing, and field commissioning of this transformer.

During the course of the substation repair, we replaced the Load Tap Changing Mechanism in the transformer with new Reinhausen RMV-II. This offered the municipal utility client updated controls, new components, new bushings, gauges, monitoring systems, and a positive pressure nitrogen system. The transformer was designed to meet specific sound level requirements due to its location in a residential area.

End to end, the substation repair project took approximately 18-20 weeks to complete – which included transportation, unloading, field assembly, acceptance testing, and onsite training by a field engineer.

For more detailed parts specifications, overall parts dimensions and transformer ratings, as well as load tap changing mechanism specifications and transformer controls related to this case study, please see the supplemental information below.

Solomon Corporation specializes in sales and service of distribution transformers. We also offer technical support to the electrical distribution industry, as well as repair, recycling, and disposal of transformers and regulators. If you wish to contact Solomon Corporation for additional information related to our experience and capabilities in the area of substation transformer remanufacturing, or to request a quote, please click here to contact our sales and procurement team.


Product Description

This transformer is used within the municipal utility industry.

Capabilities Applied/Processes


  • Core and Coil Construction
  • Core: Circular or Cruciform Construction
  • HV Coil: Circular Continuous Disk with Paper Wrapped Copper Conductor
  • LV Coil: Circular Helical Wound with Copper Continuously Transposed Cable (CTC) Conductor
  • Core and Coil Assembly Designed to Meet Current ANSI/IEEE Short Circuit Requirements
  • Core and Coil Design receives a Induced Voltage Distribution Calculation to Verify Ability to Meet
  • ANSI/IEEE Impulse Test Requirements
  • Core and Coil Designed to Meet NEMA TR1 Sound Level Requirement
  • Core and Coil Designed not to Exceed a 65 Degree C Hottest Spot Temperature Rise
  • Series Core and Coil Design is Circular Construction with Continuous Disk and Helical Copper Windings
  • Guaranteed No-Load Losses – 17,000 Watts
  • Guaranteed Full-Load Losses – 54,500 Watts


  • Complete Rewind Repair of Base Rated 15 MVA Substation Transformer w/ Low Voltage Load Tap Changer (LTC)
  • Upgrade the LTC Control and Transformer Monitoring System


  • Two Part Epoxy Primer
  • 4 Mils Acrylic Enamel
  • ANSI 70 Grey


  • Transformer Shipped on a Solomon Corporation Truck

Overall Transformer Dimensions

Length: 296″
Width: 160″
Height 182″
Oil Capacity: 4,210 Gallons

Oil Type

Type II Mineral Oil

Product Specifications

Transformer Ratings:

  • 15/20/25 MVA 55 C Rise ONAN/ONAF/ONAF
  • 16.8/22.4/28 MVA 65 C Rise ONAN/ONAF/ONAF
  • Phase: Three
  • Frequency: 60 Hertz
  • High Voltage Rating: 67000 Delta
  • Low Voltage Rating: 12470Y/7200
  • High Voltage BIL: 350 KV
  • Low Voltage BIL: 110 KV
  • HV No-Load Taps: 70600, 68800, 67000, 65200, 63400
  • Low Voltage Load Tap Changer (LTC): +/- 16 Steps @ 5/8 % steps

Load Tap Changing (LTC) Mechanism and Controls:

  • Mechanism Type: Waukesha UZD
  • LTC Control: Beckwith 2001B Micro Processor Control
  • LTC Mechanism Designed for a Minimum of 500,000 Operations before Contact Replacement is Required
  • The Control s for Auxiliary Cooling Equipment is Fully Automatic with Facilities to Start and Stop Cooling Fans as Oil or Winding Temperature Dictates
  • Control is Designed with 120/240 VAC for Auxiliary Cooling Motors and Accessories and 48 VDC for Control Power
  • The Load Tap Changer Control is Designed to be Continuous Parallel Operation with Similar Transformer

Transformer Accessories:

  • Cooling Radiators are Flange Mounted and Detachable
  • Qualitrol Sudden Pressure Relay
  • Top Oil Temperature Gauge with Alarm Contacts
  • Hot Spot Winding Temperature Gauge with Alarm Contacts
  • Liquid Level Gauge with High and Low Level Alarms Contacts
  • Combination Pressure/Vacuum Gauge with Alarm Contacts
  • Explosion Relief with Alarm Contacts
  • High Voltage Current Transformers (CT’s) Multi -Ratio 1200:5
  • Low Voltage Current Transformers (CT’s) Multi-ratio 2000:5
  • Low Voltage Neutral Current Transformer (CT’s) Multi-Ratio 2000:5
  • High Voltage 60 KV Polymer Station Class Surge Arresters
  • Low Voltage 10 KV Polymer Station Class Surge Arresters
  • Core Ground Test Bushing and Enclosure

In Process Testing Performed

Certified Factory Testing in Accordance w/ ANSI/IEEE C57.90
Resistance Measurement of All Windings, Voltage Connections, and Taps
Ratio Test on Rated Voltage and All Taps
Polarity and Phase Relation Test on Rated Voltage Connections
No-Load Losses in Watts @ 100 and 110 Percent of Rated Voltage
Excitation Current Measurement at 100 and 110 Percent of Rated Voltage
Load-Losses in Watts at Rated MVA
Percent Impedance at Rated MVA
Doble Power Factor
Doble Excitation on All Voltage and All Taps
Applied Potential
Induced Potential
Winding Insulation Resistance
Audible Sound Level
Dew Point Measurement

Estimated Part Weight

109,000 lbs.

Industry For use

Municipal Utility

Turn Around Time

18 to 20 Weeks

Delivery Location

Southern Florida

Standards Met

Manufactured to Meet or Exceed ANSI/IEEE C57.12.00 Standards

Product Name

Power Class Substation Transformer

Testimonials from our customers

Solomon Corporation is the top manufacturer of high voltage power transformer sales, service, purchasing, repair and teardown services. Below are just a few examples of our work. If you would like more information on our products or services, please contact us today.

    My crew and I were having some difficulties troubleshooting a phase transformer bank. I contacted our sales rep, because not only is he very knowledgeable about the Solomon products we were working on, he’s also a very experienced lineman.

    He must have sensed my frustration with the situation because he took it upon himself to drive to another state just to see if he could help us. Shortly after his arrival, he noticed our problem, and it was quickly resolved.

    In a time when customer service is definitely on the decline, it’s good to see that some companies and their representatives are willing to go above and beyond. This is the reason that we’ll continue to buy Solomon transformers.

    Lee Sifton

    Electric Senior Foreman

    City of Eaton Rapids, MI

    “Once again, Solomon Corporation has exceeded expectations in helping Jewell Operations meet its goals. Thank you for your continuous efforts in design, delivery, and pricing. You have set the standard for how we purchase our assets. We look forward to working with you in the future as a Vendor of Choice. Job well done.”

    Rick Taylor

    Maintenance Manager

    SunCoke Energy Jewell Operations

    Redstone Arsenal is a four star command and the headquarters for Army Material Command. The base has over 40,000 employees, mostly engineers and scientist, who support critical on-going theater operations as well as a large on base NASA operation. My responsibility to keep base operations going with available power would be compromised without having reliable power and related components. Of these components, Solomon Corporation has a critical role in keeping base operations in power. Solomon has been a mainstay at Redstone Arsenal for about 20 years. The quality of the transformers are second to none as is their customer support. Solomon Corporation is the specifying standard for transformers at Redstone Arsenal and my preference over name brand original equipment manufactured transformers. My faith in the reliability and service of Solomon is unwavering and I don’t have any reservations about recommending them.

    Pete Green

    Senior Electrical Engineer
    US Army IMCOM

    On June 26th we had a fire burn down about 2.5 miles of our 25kv distribution line. We thought no big deal, we will just haul our mobile substation over there, and we’ll be back in business. This is the same mobile substation that Solomon Corporation re-worked for us a couple of years ago. Everything went smooth until we actually energized the unit and found we had no control power to the recloser control and no power to the cooling fans.
    I got on the phone with Terry Hamel on June 27th and explained our situation to him. He and Eric Carlson were on site on July 2nd to figure out what was wrong and to make it right! I think it is important to let someone at Solomon know how much I personally appreciate that kind of service! Eric and Terry dropped everything to get all the way out to Nevada and make sure we were taken care of.
    In fact, while they were here, we had another fire burn down nine of our 69kv transmission structures, and they wanted to know what they could do to help us out with that. I don’t know of too many companies that would do that.
    We are very isolated out here in rural Nevada, and it’s companies like yours that help me do my job. Everyone I have ever worked with at Solomon has bent over backwards to make sure I have gotten everything I have needed – from Grand Junction, CO to your headquarters in Solomon, KS. You should be proud of your employees.

    Michael J. Venturino

    Substation Technician
    Mount Wheeler Power

    The Solomon Crew did another great job with their recent project at the El Paso Electric Company (EPE) sites. The crews, as they did in the past project at EPE’s Newman Power Plant, showed that they worked as a team to complete the task at hand, and most importantly, they worked in a very safe manner. They showed professionalism and good work ethic from the time they arrived at EPE to the time they left. Bill and Ken, Solomon Field Leads, were in constant contact with me, providing daily updates from the different work sites throughout the duration of the project. EPE’s substation personnel did a final walk-through of the different sites upon completion of the project, and the substation supervisor was satisfied with the sites. The areas where equipment was located were left clean and free from any debris. I also received good feedback from EPE’s Safety Sitters, who were on-site for the duration of this project, on Solomon Crew’s professionalism.

    Oscar Trillo

    Environmental Department
    El Paso Electric Company

    The Clay Center Public Utilities Commissioners and I would like to acknowledge your efforts to resolve our problem. Your personnel, as usual, reacted professionally and went the extra mile to help. The transformer was back in service within four hours of my call. Having a resource like Solomon to respond to emergencies is very valuable to a utility. I will personally remember your efforts and share my thoughts with my fellow Utility Directors. Thank you.

    Bill Callaway

    Director Of Utilities
    Clay Center Public Utilities Commission

    I just wanted to say thanks for your help and support on the 500KVA transformer problem. We had a faulty transformer at a customer location. I contacted my Solomon Corporation Territory Manager while he was attending his kid’s basketball game. He returned the call, and provided the technical help we needed to troubleshoot the transformer. We found the problem and were able to get the customer up and running without expensive downtime.
    We want you to know that we appreciate the quick response and will contact Solomon when we have future transformer needs and repair.

    Russ Hogelin

    Company President
    Cahaba Electric, Inc.