Service, repairs and lifetime extension

Karsten Moholt AS has 70 years of experience with service, repairs and lifetime extension of rotating electrical machinery. Our workshop and global presence give you high quality service and maintenance based on broad expertise and quick response time. We ensure lifetime extension and improved performance for all your equipment.

Our workshop is the leading in Norway on low- and high-voltage motors, and can handle everything from minor overhauls and repairs to large, advanced assignments. In addition to our facilities at Askøy we travel around the world to service, repair and inspect generators, transformers and electrical motors and associated equipment in the field. Our workshop is UL, NEMKO and IECEx-approved and our personnel is certified to perform installations and maintenance in accordance with IECEx & COMPEx. This means that we can take care of all your Ex equipment in our workshop and in the field.


Karsten Moholt inspects and checks the condition of your rotating equipment in the field and in our workshop. This forms the basis for carrying out the necessary service, repairs and lifetime extension.

We also carry out our own inspections of Ex equipment if needed.

Standard overhaul

Karsten Moholt’s standard overhaul covers the requirements and standards that apply to your equipment. Our standard overhaul includes an engine diagnosis, bearing replacement, a test run and report.
Should we detect the need for other repairs we will offer to do this in our workshop, as this ensures minimum transportation and downtime.

Bearing replacement

Karsten Moholt has 70 years of experience with bearing maintenance and replacement. We replace bearings quickly and professionally at our workshop and in the field and can mobilise swiftly. We have a large selection of ball and roller bearings.

Maintenance or bearing replacement reduces vibrations and heat development in the equipment, and are absolutely necessary to avoid unwanted downtime and breakdowns.


Karsten Moholt AS rewinds motors, generators, transformers and other electrical equipment. We use winding material suppliers that deliver world-class insulation materials and copper. Together with our experience and knowledge, this enables us to quickly deliver an optimal product. Karsten Moholt rewinds both high- and low-voltage, AC and DC.

After rewinding, the motor function will be as good as new or better. The alternative to rewinding is buying a new motor. Rewinding is, however, more cost-efficient and environmentally friendly, as the stator housing, rotor and shaft is retained.

Shaft alignment

Correct alignment of rotating machinery is essential to assure the lifetime of bearings and couplings. Inadequate alignment leads to vibrations that can also damage secondary components that are not part of the rotating mass.

Karsten Moholt performs precision alignment of all types of rotating machinery and use laser equipment from Pruftechnic to carry out these tasks.


Karsten Moholt carries out static and dynamic balancing in the workshop, using 2.5 and 25-tonne balancing benches, and under demanding conditions in the field worldwide. We are documented specialists (ISO 18436-2) with high-quality equipment (VIBXPERT II Balancer). We perform vibration analyses before and after balancing in order to document the effect.

Balancing gives vibrations within acceptable levels and increases the component’s expected lifetime.


Karsten Moholt has one of the world’s largest independent VPI-tanks, which measures 4 metres across and is 4.5 metres deep. We carry out VPI on a wide range of electrical machinery and components.

VPI will extend the lifetime of the machine and reduce the need for maintenance. VPI offers the best protection against all external influences such as oil, moisture, salt and chemicals in the surroundings. VPI is superior to other types of impregnation, such as spray or dip coating.

Surface treatment

Karsten Moholt AS has its own surface treatment facility, which is equipped to perform surface treatment according to NORSOK M-501 a/b and other industry-specific requirements and specifications.

Sandblasting gives the opportunity to detect and remove corrosion before applying a new surface. New surface treatment on a sandblasted surface ensures solid coverage and that the surface remains corrosion-resistant for a long time.

Test runs

Karsten Moholt test runs electric motors of all sizes. We also test heaters and coolers. After a test run we document the equipment’s condition and suggest recommended maintenance if necessary.

Machining, turning and welding

Our competent employees can carry out machining, turning and welding in most materials.