AC/DC Motor Rewinding | EASA AR100 Certification | Grupo Marro
At Grupo Marro, we understand that operational continuity is the backbone of your business. With decades of experience servicing electric motors, we deliver rewinding solutions with unmatched technical precision. Our commitment shows in every project, ensuring maximum reliability and efficiency for your machinery, backed by the international EASA AR100 certification. We perform rewinds that restore and exceed original performance.
Why electric motor rewinding matters
Learn what EASA AR100 certification means for your motor →
An electric motor with a poor winding is a latent risk for any industrial operation. Ignoring the signs of wear not only reduces energy efficiency and raises operating costs, but also leads to catastrophic failures and unplanned downtime. A professional electric motor rewinding service significantly extends equipment service life and optimizes energy consumption.
For industrial and energy companies in remote areas, where immediate technical support can be limited, a preventive rewinding program is crucial. Our rewinding service ensures operational continuity, reduces unexpected failures and enables a transition toward predictive maintenance. We specialize in rewinds for high-voltage motors, medium-voltage motors and low-voltage motors, ensuring your plant never stops. Trust our experts with your rewinds.
To guarantee the best results, at Grupo Marro we use the most advanced electrical insulation techniques and the finest winding materials (copper, resin, insulators). Every one of our rewinds undergoes rigorous insulation resistance testing and meets the strictest rewinding quality standards. This detailed approach also applies to the rewinding of alternators and generators, as well as servomotor repair, delivering a complete solution. Rewinding is a core part of our electric motor repair service. The quality of our rewinds is your best guarantee.
Want to understand the technical differences? See our guide to winding types (concentric, lap and wave).
Before and After Rewinding with Grupo Marro
See the direct impact of our service on your motors' performance. A professional rewind completely transforms the operation of your equipment.
| Aspect | Before Rewinding | After Rewinding with Grupo Marro |
|---|---|---|
| Energy efficiency | Reduced by internal wear | Restored to manufacturer standard |
| Operating temperature | High, risk of overheating | Stable and safe |
| Vibration / noise | Elevated | Smooth, quiet operation |
| Electrical failures | Frequent | Reduced to a minimum |
| Downtime | Recurring | Planned maintenance |
| Motor service life | Shortened | Significantly extended |
Why choose our rewinding service?
We combine experience, an automatic coil winder, clamshell VPI and EASA AR100 certification to deliver AC/DC motors, form-coil windings and transformers that exceed original specifications.
EASA AR100 Certification
EASA AR100 certification that guarantees rewinding processes meeting international standards of quality and reliability.
VPI Clamshell
Clamshell VPI equipment for vacuum-pressure impregnation, ensuring superior insulation and greater durability.
Automatic Coil Winder
Automatic coil winder for precision rewinding of stators and rotors with high-quality copper wire.
Megger Testing
Comprehensive electrical testing with Megger equipment to verify insulation resistance and continuity.
Our Rewinding Process
Every AC/DC motor, form-coil winding or transformer follows a rigorous 10-step process that guarantees maximum rewinding quality and reliability.
Initial Assessment
Complete assessment of the motor condition and failure analysis using specialized equipment.
Disassembly
Careful disassembly of the motor, documenting each component and measuring tolerances.
Winding Removal
Extraction of the damaged winding while preserving the integrity of the magnetic core.
Core Inspection
Thorough inspection of the stator and rotor to detect damage to the laminations.
Winding Design
Calculation and design of new windings to original or improved specifications.
Rewinding with Coil Winder
Precision rewinding with an automatic coil winder and high-quality copper wire.
Winding Connections
Interconnection of windings following electrical diagrams and international standards.
VPI Clamshell Impregnation
Vacuum-pressure process in clamshell equipment to fully impregnate the insulation with resins.
Industrial Oven Curing
Controlled polymerization in a large-capacity oven with precise temperature and time. Everything is properly baked, never burned.
Testing and Certification
Complete evaluation including insulation resistance, continuity and current balance.
Technical Capabilities
We work with a wide variety of motors and use the best materials on the market.
Motor Types
- Three-phase AC motors (induction)
- Single-phase AC motors
- DC (direct current) motors
- AC and DC generators
- Wound-rotor motors
- Form-coil motors (squirrel cage)
- Synchronous motors
- High-voltage motors
- Low-voltage transformers
- Medium-voltage transformers
- High-voltage transformers
Winding Types
- Concentric winding
- Distributed winding
- Shaded-pole winding
- Lap winding
- Wave winding
- Compensating winding (DC)
- Field winding
Technical Specifications
- Class 180°C copper wire
- Class F insulation (155°C)
- Class H insulation (180°C)
- Voltages: 220V to 13.8kV
- Power ratings: 1HP to 5000HP
- Large-capacity industrial oven
- Spreader for medium/high-voltage form coils
- Domestic and international suppliers
- Specialized VPI resins
- Nomex/Mylar insulating materials
VPI Clamshell Technology: Vacuum Impregnation
Our clamshell VPI equipment uses the Vacuum Pressure Impregnation process, the most advanced technology for treating windings in AC/DC motors, form-coil windings and transformers.
Form-Coil Specialization
We have a specialized spreader for medium- and high-voltage form-coil work. In addition, we maintain partnerships with domestic and international suppliers to ensure the availability of specialized materials and high-quality components.
Higher Dielectric Strength
The VPI process eliminates air bubbles and voids, significantly increasing insulation resistance.
Better Thermal Conductivity
The impregnated resin improves heat transfer, reducing hot spots and extending service life.
Moisture Resistance
Hermetic sealing against moisture, chemicals and environmental contaminants.
Greater Durability
Motors treated with VPI can last up to 3 times longer than conventional rewinds.
With EASA AR100 certification, we guarantee that every rewound AC/DC motor, form-coil winding and transformer meets the most demanding international standards.
- Insulation resistance testing per IEEE 43-2013
- Vibration analysis per ISO 20816
- Quality certification with every delivery
- Extended warranty on all of our work
Frequently Asked Questions about Motor Rewinding
Need to rewind your motors or transformers?
Our EASA AR100 certified experts are ready to assess your AC/DC motors, form-coil windings and transformers, providing a tailored solution with clamshell VPI technology.