AC motor repair
at DV Group
Test solutions guaranteeing 100% functional products
A variety of tools adapted to your needs:
- Winding equipment: megaohm meter, milliohm meter, probe into motor protection: CTP/PTC/PT100, Baker Index Control.
- Mechanic’s equipment: ball bearing assembly using manufacturer’s specially designed tool, induction heating, machining equipment, etc.
- Specific tools: shock wave analysis, impedance analysis, vibration measurements, balancing, etc.
- Spare parts in stock (original equipment or adaptable)
- Load bench: AC starter up to 1,000 A / load on impact 1,500 A.
- Procedure before dismantling
- Inspect motor connectors.
- Metrological check of bearing seatings, joint surfaces, flanges, shaft, etc.
- Check lubrication and evacuation ducts
- Electrical inspection (insulation, resistance, inductors, etc.) according to the data supplied by the manufacturer.
- Cooling control: ventilation and water circuit.
- Repair: chromium plating, ringing, molten metal cladding by spraying of the various joint surfaces, complete cladding of the drive shaft
- Electrical inspection: ageing, pollution: BAKER index, state of winding
- Repair: winding and dip impregnated Class H: High Temperature, turning the ring set (wound rotor motor)
- Tests: no-load tests in rotation on a platform up to 1,600 kW
- Load tests up to 600 kW at 3/4 load – 50 / 60 Hz
- Vibration measurement and signature
- Diagnosis and testing history
- Traceability produced by: machine number / customer number / DV GROUP number.
- Test sheet and qualification/test certificate
Case study :
Need / Context
Glass producers must rebuild their furnaces every 15 years. The refractory brick component needs to be replaced to ensure its tightness of fit. During this shutdown, the OI Manufacturing site in Ardèche refurbishes the related equipment. Glass production has a reliability requirement, and must be able to ensure long periods without breakdown or maintenance stoppage.
To achieve these availability and efficiency goals, the glass producer entrusts us with the removal, overhaul and refitting of its fifteen 750 KW - 50 Hz medium-voltage fan and compressor motors. For one month (800 hours), our teams from the various electromechanical sites in Grigny, Cambrai and Lyon mobilised to process these products and meet the deadlines imposed by our customer. We added DV GROUP know-how to the flawless organisation demanded by this project. OI Manufacturing has atypical 750 KW - 50 Hz medium voltage motors with plain oil bearings instead of ball bearings. These bearings carry a higher radial load and have a longer life than bearings. However, they require a specific expertise.
- Deadlines met - Furnace restart with products 100% tested and 100% functional
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for Electromechanical maintenance