RAP establishes itself as a general contractor

Following the resounding success of the first exchange project of Reinhausen Asia-Pacific (RAP) at the end of 2013, RAP once again assumed the role of general contractor. On request of Northern Utilities Resources (Distribution) Company (NUR), an on-load tap-changer from Chang Zheng Electric Apparatus Works was replaced by a VACUTAP® VM®.

As general contractor, RAP was responsible not only for delivery and installation, but also for the entire project management. The RAP project team, led by project managers Looi Peng Yong and Rosidi Mat Lazim, carried out intensive planning and technical preliminary work in advance in order to keep downtime to a minimum. This detailed advance planning and MR know-how were the key factors in ensuring a smooth transition to the VACUTAP® VMIII with the motor-drive unit TAPMOTION® ED.

The replacement was carried out in accordance with the requirements and safety standards prescribed by NUR. The transformer was reconnected to the grid in ten days, following replacement and successful final testing, and the project was also completed within the stipulated budget.

Retrofit TAPCON® 230

An MK30 AVR type MR voltage regulator was already installed on the old tap changer and had worked reliably for more than 17 years. Now it was time to replace the old regulator with the latest TAPCON 230. An MK30 AVR was also connected to a second transformer. The RAP service specialists suggested upgrading both AMK30s and the parallel control unit SKS30 with two new TAPCON® 230s. By using the TAPCON® 230, an additional parallel control unit would no longer be necessary. The TAPCON® 230 housing is the same size as the MK30 and can therefore be easily interchanged.

MR-Voltageregulator MK30 AVR.
TAPCON® 230.

The most important requirement of NUR was for the second transformer to immediately switch up one step when the master transformer switches up one step (the same applies when switching down). This was no problem for the RAP specialists. All they needed to do was set up a CAN Bus connection between the two TAPCON® 230s to allow data to be transferred ("Master Follower" function).

One of the challenges was the wiring scheme of the existing installation in regard to the current-transformer connection. This is why the service technicians decided to switch off only one transformer at a time during retrofitting.

After many hours of careful planning and consultation, the work was carried out on 20 March 2014. It was completed successfully in accordance with the specifications and approved by NUR Distribution. Commissioning took place following routine tests. Both TAPCON® 230s were then monitored for a day. No problems of any kind were found and the customer was completely satisfied with the retrofit.


Northern Utilities Resources (Distribution) Company (NUR) is a private utility which provides power for the high-tech locations in the north of the Malaysian peninsula.