Solutions in Critical Situations
 

By M. Deicke and D. Recksiek
 
The Helmke Group is an experienced specialist since 1922 in the manufacturing of non-standard drive systems designed according to the requirements of the customer. Together with its subsidiaries in France, Spain, Italy, the Netherlands, Switzerland and Sweden, it has grown into an international authority in the field of drive technology. The immediate availability of electric motors due to considerable stock capacities and individual customised solutions are some of the advantages offered to its customers.
Significant strengths of the Helmke Group are:
 
  • Project planning and engineering of drives including power electronics
  • Customized solutions
  • Design and construction of special drive tasks
  • Duplicate machines for existing drives (Fit / Form / Function)
  • Mechanical and electrical modifications of all kind
  • Extensive stock keeping of about 60,000 brand new motors
 

Case Study:
On February 4th 2009 HELMKE received; by random; the information from an independent customer that there is a breakdown of a 6400kW mill motor with slip rings in Iraq. It was said that this motor was used in a cement factory. Due to good market knowledge it was easy for HELMKE to identify the plant. At that time we were  contacted by the European technical Headquarters of our potential customer in Austria to inform us that there is a breakdown in one of his cement plants. At the same time HELMKE placed a first technical offer for a new HELMKE stock motor with the following technical parameters:
 
  • 6440kW
  • 11kV
  • 6pole
  • IC611
  • Frame 800
  • Type DSKK800-06
  • Brand new manufactured according to stock specification
 
This motor is standard stock motor which is normally directly available from stock.
 

A few days later HELMKE was contacted by the Iraqi technician; he transmitted the complete technical file of the failed ABB motor commissioned in 2007. The technician himself was very surprised about the availability of such a motor ex-stock, because he thought that nobody around the globe would have such a big motor immediately available. Obviously he was not knowing HELMKE.During the detailed technical clarification period the following points were required by the customer:
 
  • As the HELMKE motor was one frame size smaller than the original one, the customer required a foundation plate to get a 100% interchangeable motor.
  • The main terminal box had to be changed from right hand side to left hand side; view DE.
  • The rotor terminal box had to be changed from right hand side to left hand side; view DE.
  • Also all auxiliary terminal boxes had to placed on the left hand side, view DE
  • Reconnection of stator winding, because the customer wanted to have the star point available.
  • Manufacturing and mounting of an additional star point terminal box
  • Implementation of star point current transformers to achieve the possibility of protecting the motor with differential protection
  • The direction of rotation was changed from CW to CCW
  • Mounting of permanent SPM sensors for the bearings
 

All these requirements were successfully fulfilled with short leadtime by our workshop in Pulversheim; France.

Additionally our customer asked HELMKE to deliver a new starter together with the WRIM, because the old starter has had a too low insulation voltage. Also in this case HELMKE was able offer a solution ex-stock fulfilling the customers requirements, namely a liquid starter: Make: HELMKE, Type: DFA 6440/1440, brand new manufactured according to stock specification Both, motor and liquid starter were successfully tested in our own Drive-System-Testfield in Pulversheim, France. The customer, who witnessed this test, was completely satisfied. Only a few days after technical clarification a brand new 6440kW, frame 800, 25,000kg WRIM was ready for dispatch, completely fulfilling customer’s specification. The lead time for the HELMKE stock motor was much shorter than the estimated repair time of the failed 2 years old motor.

 

To make a contribution to a short down time of the whole plant it was discussed to air freight the motor and the starter to the cement plant, even though the motor weight alone was about 25,000kg. Together with the customer’s and HELMKE’s logistic experts a solution was found which reduced the transportation costs significantly, but which also had nearly no influence on the downtime.

Meanwhile the HELMKE motor has been commissioned at site, completely fulfilling the customer’s requirements. The commissioning was carried out under supervision of HELMKE.

Conclusion:
The modern cement industry requires high reliability, high availability and high flexibility, notwithstanding the fact that assets and spares have to be reduced. All operational managers and responsible persons have to survive in this area of conflict. Based on basic motors ex-stock, high flexibility in engineering and production, combined with non-standard logistic solutions HELMKE is able to offer a DRIVE-partnership to customers. With 60,000 electric motors in our different warehouses we are able to discuss also your tailor-made maintenance, service and spare concept.