AC/DC Machine Services and Rewinding
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Machine Shop and Motor Rewinding Services
Global Electronic Services offers a total range of machine shop and motor rewinding services for electric motors of all sizes. We’re an industry-leading partner focused on getting your motor back up and running so your operations can minimize downtime and get back to profitability.
What Is Electric Motor Rewinding?
What are electric motor rewinding and electric motor rebuilding services, and why do you need them? Rewinding is the process that we sometimes use as a way to repair shorted, grounded or damaged motor coils. When we perform our DC motor rewinding service for your motor, we can then return the rewound coil and reinstall it with rebuilt armatures or other components as needed to get your motor functioning properly again.
When to Rewind an Electric Motor
Even well-built motors are vulnerable to wear and tear over time. It may be time to rewind an electric motor when you notice the following signs:
1. Evidence of Deterioration
One of the telltale signs that a motor requires rewinding is visible deterioration. Your company might notice broken components, burns or contamination such as rust or moisture.
If you see evidence of deterioration, your company will want to figure out whether the laminations in your motor are also damaged. If so, you may need to replace the motor. If not, rewinding may be the right option.
2. Diminished Winding Resistance
Your company may notice poor winding resistance in a motor, or a professional may measure poor winding resistance. For example, a professional may use the winding resistance test to determine whether shorted coils in the motor are causing performance issues.
Start assessing winding resistance by looking for the motor’s nameplate or checking the manufacturer’s instructions that came with the motor. One of these places should show the motor’s optimum winding resistance level. If the measured numbers show a significant discrepancy from the optimum level, rewinding is probably necessary.
3. Issues With Insulation Resistance
A motor that needs rewinding can sometimes develop issues associated with insulation resistance because the coils in the motor start to short.
Shorting and low insulation resistance can occur for many reasons, including power surges, excessive vibration and contamination. A motor that needs to be rewound can generate these issues. Low insulation resistance causes numerous difficulties with the motor, including insufficient lubrication and damage to components.
Is Rewinding a Motor Worth It?
In some cases, replacing your motor may be a better option than rewinding it. On the one hand, replacing the motor is much more expensive. Rewiring can save you money in the short term while extending the life of your current motor. On the other hand, the added investment may be worth it because it gives you a new motor with years of high performance.
Rewinding is often more cost-effective and environmentally friendly because it reuses the core motor materials. Creating a new motor from all-new materials has a much higher carbon footprint and overall environmental impact.
However, this rule of thumb becomes complicated when you consider that a new motor may offer cost savings and environmental benefits in the form of increased energy efficiency. So your company may need to do some calculations to determine the right solution for your operations and budget.
How can you tell the difference between the two scenarios? In general, if a motor is very old, a replacement may provide better value than rewinding because the motor may break down or require increased rewinding frequency as it ages. Or an older motor may be so extensively damaged that rewinding cannot improve its performance significantly. If the motor is relatively new, though, rewinding offers a cost-effective way to boost its performance and extend its life span.
Essential Questions to Ask
Here are a few questions your company may want to ask as it considers its options:
- Does your business prioritize keeping operational costs low?
- Does your business prioritize efficiency?
- Does your business want to benefit the planet and appeal to eco-conscious consumers by reducing its environmental impact?
If the answers to these questions are “yes,” then rewinding your motor is likely to be the option that provides the most value and aligns best with your company’s goals.
When to Rewind
Your company will likely want to rewind a motor if most of these conditions apply:
- The motor is noticeably deteriorated, exhibiting signs of burns, component damage, rust or moisture.
- The laminations remain in good condition.
- The winding resistance has decreased.
- The motor is not much more than about a decade old.
When to Replace
On the other hand, your company may need to replace the motor if most of these conditions apply:
- The magnetic core of the motor is in poor condition.
- Bearing failure has occurred to the point of significantly damaging the armature and stator.
- The motor has otherwise sustained extensive or irreparable damage.
- The motor has previously undergone incorrect rewinding.
- The motor is more than about a decade old.
Our Motor Rewinding Process
When we perform our electric motor rewinding services, there are several steps we go through:
- Record pertinent data: We start by recording all the necessary data that is needed to rewind the motor, including the number of slots, number of coil turns, pitch and necessary wire size for making coils to rewind the motor.
- Remove faulty windings: Once we record the necessary data and enter it into our database, it’s time to remove the faulty windings. We then remove any leftover varnish, insulation or contaminants before rewinding the motor. We have a piece of equipment called a media blaster that effectively removes debris and particles without damaging the motor.
- Steam clean the stator and paint with insulation paint: After this, we steam clean the stator and all the other parts of the motor to make sure they are free of contaminants. Once it is all clean, we paint inside the stator with insulation paint. We then install liner insulation in the stator slots so that the coils do not contact the core.
- Make new coils and add to the stator slots: Now it’s time to make new coils. The type of winding head we will use to wind the motor will depend on what type of motor it is. The person doing the winding tests the wire for any defects while the winding process is taking place. Once the coils have been created, it’s time to add them to the stator slots as appropriate. When the coils are in place, we add wedging to insulate and protect the coil.
- Add lacing and varnish: The next step is to add lacing for additional stability. Finally, we connect new motor leads followed by a thorough quality test. A dielectric test confirms the integrity and quality of the windings. The last step is to heat the motor in an oven for dipping in varnish. The varnish bonds the windings together and prevents the coils from moving. It also is a way to protect the windings from contamination.
- Cure the motor and test: The last step is curing the motor and then re-testing to make sure that the motor is working optimally and as intended.
While this seems like an intense and heavily involved process, it is practically automatic for our trained repair technicians at Global Electronic Services. Our technicians have wound countless motors and know the process by heart. You can be confident that when you contact Global Electronic Services for your motor rewind and repair services, you will find yourself with a quality motor that works virtually like new at the end of it.
AC & DC Machine Shop Services and Rewinding
Here are some of our primary machine shop services:
- Coil winding machines
- Milling machines
- Turning and undercutting armatures
- Keyway cutting
- Shaft fabrication
- MIG, TIG and arc welding
- 30,000-pound dynamic balancing
AC and DC Motor Rewinding Services
Global Electronic Services has perfected the process to rewind AC and DC motors, ensuring exceptional repair and rebuild.
A properly planned and executed motor rewind will cause no efficiency loss in electric motors, but you may see improvements in power density, reliability and overall efficiency thanks to leading equipment and practices that your Global Electronic Services certified technician will use.
Your rebuild and motor rewind may include some additional improvements you haven’t considered, such as upgrades to the latest resins and insulating tapes that can improve overall thermal dissipation, especially when working on older motors.
As a qualified service provider, we always ensure your rewound motor is brought back up to OEM standards and efficiency expectations. Giving you the best rewinding service for electric motors starts with a complete review to understand if there is any problem with your motor that you were unaware of during submission.
If we discover anything, we’ll contact you right away with an updated quote and information on our concern. You must give us approval before any work is performed, so we are both in agreement for the final cost.
Global Electronic Services repair technicians hate it when we take our car to the garage for one thing and get a bill for 20 others. We promise never to do that to you, which is why we have a thorough quote and approval process.
Our rewinding services for motors follow a very strict process to maximize speed and efficiency while minimizing any risk to core integrity. Core elements of our process include:
- Windings are stripped carefully while the strength and structure of the core are maintained.
- Coils are rewound by a computerized machine to maintain regularity and accuracy.
- Rewind materials include copper and insulation.
- Windings are then tested electronically.
- Stators and armatures are processed through varnish machines to finalize the rewind.
Best Practices for Electric Motor Rewinding
If your company decides to extend an existing motor’s life span with rewinding, getting the most value from the process should be a high priority. Here are a few best practices to keep in mind for an optimal electric motor rewind:
1. Best Practices for Stator Core Processing
If the core of the motor has sustained damage, it will need repairs before rewinding occurs. For example, if laminations have become flared, the teeth will need to be bent at the end of the middle slot. If the laminations have become slightly eroded, laminations will need to be restacked in the affected areas to fill in the eroded spots. Laminations that have sustained excessive damage will require complete replacement.
2. Best Practices for Winding
Once the stator core has been dealt with, the rewinding can proceed. One essential tip for winding is that insulation resistance must stay consistent. Technicians maintain insulation resistance during rewinding by using the same wire area size and the same average length of turn.
If space allows, technicians can increase the wire area, leaving less space between the wires. This practice reduces air pockets and enables increased heat transfer capabilities. It also reduces the winding temperature and minimizes copper losses, so the motor efficiency improves and the windings should have a longer life span.
3. Best Practices for Repairs During Rewinding
During rewinding, minor mechanical repairs may become necessary.
For example, bearings in the motor may be worn and require replacement. If so, the replacement bearings should be the same as those initially provided through the manufacturer. Proper bearing installation is also critical — otherwise, the bearings will quickly fail.
During bearing replacement, the technician should also refill the grease cavity partway. If sealed bearings are necessary because of the motor conditions, the technician will likely use non-contact seals to prevent contaminants from entering.
4. Best Practices for Maintaining Proper Ventilation
During rewinding, the technician may increase the wire current capacity, which can improve the fan efficiency and enable the use of a smaller fan, reducing windage loss. The technician should also replace any damaged or broken fan blades and position the fan and its cover strategically so they do not impede airflow through the motor.
5. Best Practices for Rewinding and Motor Design
The technician rewinding the motor should be careful not to alter the magnetic flux level of the new winding substantially, though a slight increase may be necessary. A double-layer winding should always be replaced with another double layer, never a single layer. Additionally, if the rotor requires rebarring, the new bar and ring material should match the original material in its resistance. Testing the old material is often necessary to ensure a proper match.
Get More With Global Electronic Services Motor Rewinding Services
When your company is looking for electric motor rewinding near you, make Global Electronic Services your trusted source. Our professional machine shop and electric motor rewinding services mean your company will never worry about your motor again when you hand it over to Global Electronic Services. We have the right technicians, equipment, parts and machining capabilities to get your motor back up and running at peak efficiency.
Plus, all the motor repair work we do is covered by an 18-month in-service warranty to give you peace of mind. We’re so confident in our rewinding services for electric motors that we exceed the industry standard 12-month warranty.
Give your company the security it needs with a leading partner that offers 24/7 customer support, order and status tracking and a quick service designed to minimize downtime. We’ll get you back on your feet as soon as possible, so contact us for a quote and ask about our one- to two-day rush service.