custom solutions
  • Reverse Engineering
  • Load Tap Changer Failure Analysis
  • Design Enhancements
  • Product Upgrades

Reverse Engineering

reverse engineerThe Waukesha® Components group has built a strong reputation as an industry leader in reverse-engineering, design enhancement and manufacturing with exceptional quality and service. Our success in this area can be attributed to a continued commitment to utilizing new materials and technologies to fuel the development of new products and solutions to the electric industry’s needs.

The reverse-engineering process starts with a customer need and sample component. We begin with a precision assessment and thorough documentation of the component geometry and dimensional information. Component geometry is measured electronically using a Coordinate Measuring Machine (CMM). The measurements are downloaded into an integrated CAD/CAM system with cross-section components integration capabilities. Exhaustive analysis and testing of materials is then done to establish composition, mechanical and electrical properties. Only materials that are equal to or exceed OEM specifications are used. Finally, an understanding of the form, fit, function and typical failure modes are reviewed with the customer to gain a thorough understanding of how the component is used prior to the output of drawings to be used in manufacturing the part.

reverse engineerShown here is an in-tank load tap changer originally manufactured by Mitsubishi® in Japan. The project consisted of reverse-engineering and manufacturing of the complete diverter switch and resistor assembly. Reverse engineering and design work consumed over 600 man-hours including over 400 man-hours of engineering time.

For more information on our reverse-engineering capabilities or the process, please contact us.


Load Tap Changer Failure Analysis

We defined the standards for high quality and reliable load tap changer overhauls/upgrades, starting with our industry-leading conversion and overhaul of the GE LRT200 in 1994. This overhaul and the many years of experience gained since then have given Waukesha the knowledge and expertise to develop thorough and comprehensive LTC refurbishment programs for a variety of LTC models.

The first and most important step in the LTC rebuild process is a thorough inspection to document the condition of the load tap changer as received and to determine the most probable failure mode(s). Following this initial inspection, the entire mechanism is completely disassembled and all parts physically evaluated for wear condition and failure damage, including hi-pot and wear evaluation of vacuum interrupters (if present). Scope of work is then defined detailing all parts to be reused and new parts needed to complete the overhaul/upgrade. A final repair report detailing all items replaced/reused and a failure analysis showing "as received" condition and mode of failure is available upon request.

For more detailed information on our load tap changer overhaul process as well as which manufacturers’ models we work on, please visit the LTC Overhauls page of our website or contact us.

Design Enhancements

At SPX Waukesha, we understand that today’s utilities are driven to improve asset management more now than ever. This has lead to higher loads over longer periods of time with less maintenance on an aging base of substation electrical equipment. The result: the need to repair and upgrade existing equipment with the latest available technology for increasing load capacity, improve reliability, eliminate "typical" failure modes and/or extend maintenance intervals. Our extensive experience in reverse-engineering and our ability to redesign and upgrade has made Waukesha an industry leading provider of enhanced design replacement components.

Diverter Casting Example of Contact with Coking
FEA Analysis on TC546 Diverter Casting Example of Contact with Coking

We utilize the latest technology and design tools when developing a design enhancement. Our engineering team uses 3-D modeling to test-fit mating parts and determine acceptable tolerances as well as perform Finite Element Analysis (FEA) to evaluate mechanical stresses when redesigning an original part.

Ferranti Packard TC25RT32
Reversing Switch with ELR® Inlay
Enhanced Life Interrupter Materials


The Waukesha® Components group has pioneered many design enhancements such as:

  • ELR® (Extra Low Resistance) Series contact design for LTCs that eliminates heating and carbon build-up (coking)
  • Self aligning selector contacts and upgraded diverter castings for the FPE TC 525 and TC 546 load tap changers
  • Spring redesign using stainless steel capable of maintaining spring rate at higher operating temperatures
  • Upgraded oil circuit breaker interrupter materials with longer arc erosion life
  • Materials upgrade from moisture absorbing phenolic to moisture resistant fiberglass reinforced epoxy
  • Thorough in-house LTC overhauls/upgrades on many makes and models including GE LRT200, Seimens TLH, TLF, TLG, & TLS series
Original GE LRT200    Overhaul with design enhancements
Original GE LRT200   HVS LRT200-2 Conversion/Upgrade
with Design Enhancements

For a custom solution to a unique equipment problem, contact us or fill out our General Inquiry form.

UTT/UTT-A Cam Switch Upgrade Assembly

UTT/UTT-A Cam Switch. INSET: New Electrical Cam Switch

Duplicate Function, More Robust Design

Designed as an economical and functional direct replacement for the OEM assembly, this re-engineered cam switch assembly for Westinghouse’s UTT and UTT-A Load Tap Changers offers precision-matched gears and all ball bearing construction for smooth, no-slip operation. This completely redesigned unit features a new electrical cam switch and can be “dropped in” without any modifications for quick and easy installation.

Improved Solution for OEM Part Replacement

  • High precision gear mechanism reduces/eliminates slippage
  • Simplified, robust design includes a Waukesha-proprietary electrical cam switch with silver-to-silver contact points for lower contact resistance (electrical switch also sold separately)

Quick Installation

  • Complete, “drop in” replacement includes all new cams, electrical switches and drive gear
  • Utilizes existing OEM wire harness
  • Factory-timed; no modifications necessary

Easy Timing Calibration

Position indicators and switches’ electrical states are silk-screened directly on the unit’s faceplate for easy timing verifications.



 Experience Waukesha


SPX Waukesha Home