Repair and overhaul

Our repair plant in Willich includes a winding department that specializes in the rewinding and repair of the following motor windings.

• Low-voltage windings up to frame size 710
• Direct current radome wound and form coils
• Rod windings
• Slip ring rotor bar windings
• Medium-voltage windings in shaped coils
• Medium-voltage windings in semi-formed coils
• Solenoid coils in almost any size
• Servomotors
• Pyrolytic oven

Engine overhauls are crucial for extending the service life and preventing defects. The comprehensive overhaul process includes disassembly, inspection, repair, cleaning and assembly. Value retention through the replacement of aged parts. Strict quality controls and performance tests ensure optimum results.

The HEMPEL electrical engineering team (HEM) quickly identifies damage and develops customized repair concepts. In doing so, we pay the necessary attention to bearings, fits, the application or bushings of shaft seats. We use high-quality spare parts and modern repair techniques for repairs.

By using vacuum technology, we optimize the penetration of resins into cavities, effectively preventing moisture from entering impregnation systems. This method is used specifically for the impregnation of electric motors, generators and in the manufacture of transformers. The vacuum process ensures an even and thorough distribution of the resin, which leads to improved performance and extended service life of the electrical components.

The precise balancing of electric motor rotors as well as fan wheels, belt pulleys, pump impellers and other rotating parts plays a decisive role in our range of services to ensure stable operation and an extended service life. Unbalance vibrations can be reduced to the limits of detectability, resulting in impressively smooth-running motors.

The repair of explosion-protected motors and devices requires special attention, and the operator is obliged to select a qualified repairer. Before recommissioning, the repaired machine must be inspected and certified by a competent person with official approval in accordance with the German Ordinance on Industrial Safety and Health (Betr.SichV) and the Technical Rules for Industrial Safety (TRBS).

HEMPEL has specialized in the repair of explosion-proof motors for over 50 years and carries out all the necessary approvals. At our facilities in Willich and Zeitz, we now have a total of 6 officially recognized “ex-experts”. In this way, we ensure that professionally supervised work is always carried out with all the necessary tests and certificates, even for round-the-clock repairs. The repair standard DIN EN 60079-19 forms the background for repairs that take into account all technical and legal aspects as well as the safety and availability interests of the operator.

In the field of electrical explosion protection, we cover various types of explosion protection, including

IEC60079-1: Flameproof enclosure Ex-d, DIN EN 60079-1
IEC60079-2: Pressurized enclosure Ex-p, DIN EN 60079-2
IEC60079-6: Liquid encapsulation (electr.) Ex-o ?
IEC60079-7: Increased safety Ex-eb, DIN EN 60079-17
IEC60079-11: Intrinsic safety “i”
IEC60079-15: non-functioning during operation “n”  Old: Ex nA Now: Ex ec
IEC60079-31: Protection by enclosure (dust protection) “t”

Maintenance, repair and any permitted modifications are carried out in accordance with DIN EN 60079-17 and DIN EN 60079-19.

Sandblasting, glass blasting and steam blasting, dry ice blasting – In the steel cleaning of electric motors, we rely on various effective methods to ensure fast, gentle and comprehensive cleaning that enables smooth findings or repairs. Oily windings, dirty end shields, rotors, bearing caps and other components are cleaned efficiently and effectively.

Our special servo test bench enables us to test and operate servomotors from a wide range of manufacturers and with different operating modes. Tests can be carried out in open up mode as well as close up mode with and without brake for inspection including torque measurement. This enables us to identify damage to servomotors and repair them in a targeted manner.

Encoders and feedback systems play a decisive role in improving the precision and controllability of electric motors.

The provisions in the standard DIN EN 60204-1 (VDE 0113-1):2019-06 regarding the testing of machine equipment are basic guidelines that initially apply to the individual test at the manufacturer’s premises and then to the initial test at the installation site. Our experts adapt these specifications to the specific requirements of the machine in question and its place of use. The standards, specifications and conditions require that the testing of the electrical equipment of a machine at the place of use is regarded as a separate work step.

We realize individual painting requests. Painting is one of the final steps after engine overhauls and repairs. The color design is adapted to the original manufacturer’s paintwork or the specific color design requirements of our customers.

At HEMPEL Antriebstechnik (HAT), we offer you comprehensive advice and a wide range of spare parts, including: End shields, slip ring assemblies, collectors, fan blades, fan cowls, forced cooling fan cowls, fans, PTC thermistors, thermal switches, PT sensors, terminal boxes, carbon brushes, brush holders, brush bridges, couplings, coupling rubbers and much more.

HEMPEL Elektromaschinenbau specializes in the individual production, adaptation and redesign of electric motors. We offer customized solutions for electric drives in industrial plants, from selecting the right electric motor to on-site installation and disposal of the old motor – all from a single source.

The professional storage of engines and replacement machines is a decisive factor for their spontaneous usability, optimum performance and longevity. In our company, we set the highest standards for the storage of electric motors.

Protection against vibrations
During storage, we take special care to minimize the introduction of external vibrations and protect the engine from unwanted shocks. These vibration-damped bearings protect the roller bearings from micro-vibrations and thus extend the machine’s service life.

Consideration for environmental influences
The ambient conditions during storage are of fundamental importance. It is therefore crucial to carefully control the factors of ventilation, temperature and humidity to ensure optimal storage.

Optimum maintenance of rolling bearings
We regularly turn the motor shaft during storage to prevent damage during downtime. This avoids premature bearing failures.