En bref :
  • Shock wave monitoring of 46 7.5 KW (400V) to 750KW (5000V) induction motors
  • Number of project hours: 75 hours
  • Project duration: 2 interventions in 2 years

CLIENT EXPECTATION

Arkema Saint-Avold, a major world player in chemical products and more particularly speciality chemistry and performance materials, chose to construct a new storage hall for its induction motors. Indeed, the current hall was dilapidated and offered poor storage conditions. It was imperative to carry out an electrical check in order to be totally trouble-free regarding the condition of the motors before moving them and thus safeguard production.

DV GROUP SOLUTION

In order to reach this objective, we advised our client to carry out a shock wave check of the motors in order to obtain a precise view of their electrical condition, so our experts carried out a check of the 7.5KW (400V) to 750KW (5000V) induction motors in two stages.

WORK CARRIED OUT

DV GROUP technical solution:

Our experts used two tools to carry out the shock wave tests:

  • the AWA IV for low voltage motors (test up to 4 000V)
  • the D12R for medium voltage motors (test up to 12 000V).

These two tools, also called Baker Analysers, allow the analysis of the motor winding mechanisms on static motors. Indeed, they incorporate a wide range of electrical tests which respond to high-quality standards. Thanks to their on-board software, the systems allow the test sequences to be automated and to follow and trace all the results of an installation directly during the check. In this way, according to the observations, our experts were able to adapt the tests progressively during the operation and they were therefore even more precise.

Several tests were carried out:

  • Motor winding resistance measurement (Balance Resistance or L-L test) to check phase balance
  • Insulation resistance measurement (Megohm test) to check the quality of the insulation
  • Polarisation index (Polarisation Index test) to check the isolation’s level of ageing and pollution
  • Dielectric rigidity test by DC scale (DC Hipot test) to check the quality of the insulation
  • Impulse or shock test (SURGE and Pulse-to-Pulse test) which allows detection of:
    • the condition of the motor winding
    • a fault in the insulation between spire, phases and winding
    • a coil fault

Following the operation, our experts carried out an analysis of the data gathered and found that four motors presented faults:

  • Two motors revealed an insufficient level of motor winding insulation owing to the surrounding damp environment. We advised our client to overhaul the motors with washing and steaming or regular monitoring to anticipate breakages.
  • Two motors had deteriorated and required intervention before use: one of them was highly polluted and the motor winding of the other was in a generally poor state. We therefore advised our client to carry out a complete winding of both these products.

CLIENT GAINS AND BENEFITS

  • Motors made more reliable (electric)
  • Economic gain
  • Establishment of a climate of trust: frequent, on-going exchanges and support from a dedicated DV GROUP contact