Reinhausen Manufacturing (RM) Modernizes nine Transformers in California

The largest Asset Management order for the REINHAUSEN Group to date

The Orangecrest substation in Riverside, California was the last station in a massive asset management project by Reinhausen Manufacturing (RM). The RM colleagues modernized nine transformers for the City of Riverside Public Utilities (RPU) in just five months.

By signing the final service reports and shaking hands with the responsible persons working from the utility company, the REINHAUSEN Group successfully concluded its largest single Asset Management project in the company’s history so far.

City of Riverside Public Utilities (RPU) is the municipal utility of one of the largest cities in California, located in the greater Los Angeles region. RPU owns and operates 15 substations, of which 10 are distribution stations served at 69 kV. Because of increasing load in RPU’s electrical network, the utility sees high importance in transformer reliability. Therefore, RPU awarded RM in 2015 with an order to modernize 9 of its transformers. The scope of work extended from transformer condition assessment through tap-changer and bushing replacement to the upgrade of transformer accessories and controls.

REINHAUSEN Group’s engineering expertise was a key factor in the successful execution of the project. One special challenge, for example, was to make sure the old Allis Chalmers tap changers could be removed from the transformer safely and their original preventive autotransformers replaced by new ones.

Once all nine transformers were back in service at Riverside Public Utilities, Luis Chadinha und Nick Pratt had only a little time to catch their breath as RM is already preparing for the next transformer modernization project in the US.



The field modernization of nine transformers within a limited time period is only possible with exact planning and outstanding project management. Nick Pratt, Transformer Service Manager East at Reinhausen Manufacturing, made sure that everything was on site on time while project manager Luis Chadinha worked head first inside a transformer to personally adjust the selector connecting leads to the new VACUTAP® RMV-II tap changer.

In addition to the tap-changer retrofit, the team of four RM transformer service technicians on site carried out the following activities: processing of the transformer oil, replacemant of bushings and gaskets, repairing leaks, installing and wiring all new Messko accessories (MSense® DGA sensors, MTraB® dehydrating breathers and MPreC® pressure relief devices) and commissioning new TAPCON® 250 voltage regulators.

As the project manager, Luis Chadinha was very proud of the successful job. "We have proven that REINHAUSEN Group is capable of handling complex transformer retrofit projects with its resources. This also gives customers an absolute added value in that they always have the same employee from RM as a contact partner," he explains. "The team is also a key factor for efficiency. Working with our own crew and equipment allowed us to finalize the project even two weeks ahead of schedule," Nick adds.


Reinhausen Manufacturing scope of work
  • Testing of the 9 transformers before and after retrofit.
  • Replacement of 9 Allis Chalmers TLH21 type reactance-type tap-changers with Reinhausen VACUTAP® RMV-II.
  • Internal work, such as adjusting the tap selector leads.
  • Replacement of 9 Preventative Auto Transformers.
  • Perform all tank modifications incl. welding services.
  • Installation of 9 TAPMOTION® MD-III motor-drive units.
  • Installation of 9 TAPCON® 250 voltage controllers.
  • Installation of full sets of Messko accessories.
  • Transformer control cabinet modification along with wiring work.
  • Replacement of HV bushings on 4 transformers.
  • Transformer regasketing.
  • Vacuum oil processing and filling of all 9 transformers.
  • Updated drawings and electrical diagrams included with final reports.