Electric Motor Rewinds

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Beatson Fan & Motors, based in Sheffield, offer a bespoke electric motor rewinds service.

The business has been family-run in Sheffield since its inception. Our founder, Herbert Beatson, opened a handful of small workshops a disused brewery in 1928, and the business has been handed down through three generations since then. Our current premises on Newhall Road is home to our entire operations, we keep all our stock here, in addition to performing all repairs and rewinds for our customers.

We offer:

  • Free local collection and delivery service for all motor rewinds

  • Free testing and quotation

  • 24-hour service if required

  • Full 12-Month Parts and Labour Guarantee

Reviews

“Fantastic service, I wish more companies were like this one, thank you Tom Beatson” – Dean Cee, Google

“Commercial and industrial fan suppliers and repairs. Great service and friendly staff.” – Donald Foy, Google

“Friendly helpful service , they have always managed to source what I needed at sensible prices .” – Andrew Ormerod, Google

Get in touch using the contact form at the bottom of the page, or call us on 0114 204 4831.

Our Motor Rewinds process

1. First Inspection

You’ll send us the motor, or if you’re local to us we’ll pick it up from you. We will then inspect your motor to determine what the issue is. We may ask you questions related to how often the motor is used, what kind of operating environment it is in, and whether you’ve had any rewinds performed before. This will help us determine the source of the issue so that we can select the right course of action.

2. Dismantling

Unless the issue is evident immediately, it is likely that we will need to dismantle the motor to examine it fully. Our experienced team have dismantled and re-assembled hundreds of motors, so your machine will be in safe hands. After this has been done we will be able to determine the source of the issue and be able to offer you a bespoke quote for the rewind or repair. We are not obliged to re-assemble items which have been dismantled for quotation purposes only.

3. Removal of Winding and Cleaning of Core

If you decide to go ahead with the motor rewind then our team will get on with the task of recording the winding detail on data sheets, before carrying out core loss testing and then removing the old winding. It’s important for the stator core to be properly cleaned at this point so that the motor is properly prepared for rewinding.

4. Rewinding the Motor

Once the motor has been properly prepped we’ll get on with the rewinding, ensuring that the original winding configuration is duplicated for optimal efficiency. In some cases, our engineers may be able to identify a different style of winding that will match the motor’s performance. Once the rewinding is completed, we’ll conduct a series of tests to ensure that all is performing as it should be, before re-assembling the motor.

5. Collection or Delivery

Once the job is completed we’ll happily arrange a free delivery (if you are local to us), or enlist a trusted courier service to deliver you motor. Alternatively, you’re more than welcome to pick up the motor from our shop yourself.

Get in touch using the contact form at the bottom of the page, or call us on 0114 204 4831.

How to determine if your motor needs a rewind

1. Rule out obvious causes

To determine if your motor needs a rewind, it’s sensible to first rule out any obvious causes. Start by assessing the condition of your motor and make note of any physical defects that the motor has. Obvious issues could include broken mounts, scorch marks and contamination from water or rust. After you’ve made a preliminary inspection of the component then you can try rotating the shaft by hand. If you’re unable to move the fan, then an obstruction or failed bearings could be the issue, as opposed to a winding issue.

2. Measure winding resistance

Once you’ve determined that the motor is not failing due to an obvious mechanical reason, you should take a measure of the winding resistance to see if any shorted coils are to blame. Before doing this you should have a note of the component’s expected resistance, this is normally found on the nameplate, but you can also find it on the manual or from the manufacturer themselves.

3. Compare resistance measurements

Compare your resistance measurement with the expected measurement (being sure to take into account the ambient temperature at the time you take the reading, as this may impair your ohm reading). Should you find a disparity between the two figures then your motor may require a rewind.

4. Measure insulation resistance

Insulation resistance (IR) is another measurement that you can use to determine if your motor is in need of a rewind or not. These measurements can be taken between windings, and between the windings and earth point. The IR value should preferably be greater than 100M ohms and a minimum if 2M ohms. A measurement of fewer than 2M ohms indicates that the insulation is deteriorating, or has failed already. Many winding faults can be attributed to low IR. Contamination, power surges, excessive heat, vibration or damaged wires can all contribute to creating a low IR. In some cases, a thorough clean and dry can help to fix these issues, but often an electric motor rewind is the most efficient route to resuming optimal performance.

Get in touch using the contact form at the bottom of the page, or call us on 0114 204 4831.

How to rewind an electric motor

1. Clean work surface

Clean your work surface using a lint-free cloth, making sure to get rid of any dust or debris that might have collected. Be extra sure of cleaning away any metal shavings, as the magnetic components of your electric rewind could attract these and cause problems when later down the line.

2. Remove the motor from its housing

You will likely need to unfasten several screws on the motor’s housing to get access to the stator (the steel drum encasing the motor), armature (the bearing-like piece at the centre of the motor) and windings (the copper wire wrapped around the stator). Place the screws in a safe place to ensure they do not get lost.

3. Take note of the motor’s configuration

Take photos from multiple angles so that you can refer later to how the motor was originally set up. If you are able to, film the following steps, as they may help when it comes to reassembling the motor.

4. Remove armature from stator

Protect your hands with gloves before forcing the armature out of the stator. Once the top of the armature has been removed, you may need to apply some force as you’ll be working against the magnets that are surrounding the stator. Whilst doing this you should take care not to damage the armature. Once you’ve removed the stator, set the housing side, away from any metal items.

5. Remove the original windings

Use a screwdriver to pry open the tabs on the brush tabs. Depending on the motor that you are working there may be up to 16 tabs to pry open. Try to avoid bending or damaging these tabs as you work, if they break off then it may be difficult to keep your replacement windings in place.

6. Cut the old winding

Use a pair of wire cutters to cut the old windings one at a time at top of each protruding post. Make sure to keep count of the number of winds in each coil, so that you can match this configuration later on. This could take some time, but cutting more than one wire at a time can make this task unmanageable.

7. Sever coils from stator

Protect your hands with thick gloves before pulling the severed coils from the stator by hand. You may need to use pliers or a screwdriver to get extra leverage. If the coils do not move after a couple of pulls, then you may need to check if any wires remain connected to the posts at the bottom.

8. Check and replace insulation paper

Once the coils have been removed you can check the insulation paper lining the stator for damage or burning. If the paper is intact you can move on to the next step, if not then you will need to replace this insulation. To do so, measure the width of the slots inside the motor and cut your insulation paper to fit. Gently fold the paper before slipping them into the slots in the stator.

9. Source correct replacement wire

Source the same gauge of wire that was used for the original winding. Consult online resources relating to your engine to find the correct size. If you are unable to find information related to your engine, then you should use a gauge that is larger than the original windings, to reduce the risk of overheating.

10. Recreate original winding pattern

Refer to your photos, notes or videos before recreating the original winding pattern using the new wire. Make each coil as tight and compact as possible. This is a complex process, mishandling it could lead to the motor failing, as such this shouldn’t be considered a DIY task. Many will choose to hire a professional to complete the rewinding.

11. Secure tabs around the stator

Once in place, each winding should be secured using the tabs around the stator. Lower the relevant tab down after your complete rewinding each section. At this point you may be able to remove a small amount of insulation paper, to ensure that there is a clean connection between the wire and tab.

12. Connect loose endings to starting tab

Connect the loose endings of the first and last windings to the starting tab of the stator. Twist both of these wires tight around the edge of the tab to complete the circuit. Before reassembling the motor, you should do a last-minute check that none of the wires connected to the tabs are making contact with each other.

13. Reassemble the motor

Using any photos or videos to assist you. Insert the armature into the stator, and then fit both back into the housing of the motor. Repace the endplates using the screws that you set aside earlier and prepare to test the motor.

Get in touch using the contact form at the bottom of the page, or call us on 0114 204 4831.

FAQs

What is a motor rewind?

A motor wind is a necessary process that enables old or well-used motors to regain some or all of their efficiency. Over time, all motors are prone to lose the efficiency that they initially ran with. Whilst some may find it financially convenient to replace their old motors with new models, this might not be an option for others who rely on a piece of older machinery to aid their processes. A motor rewind performed by skilled, experienced tradesmen can rejuvenate older motors so that they can perform as efficiently as possible. Motor rewinds are often the most cost-effective solutions to servicing smaller motors and is the only service option for obsolete motors.

How do you rewind a single-phase motor?

Rewinding a single-phase motor requires skill and experience to do correctly. You will need to pay close attention to the winding pattern as these vary from one motor to the next. 

How much does it cost to rewind an electric motor?

The cost of an electric motor rewind varies depending on the size of the motor, and the complexity of the winding pattern. 

Can you fix a burnt-out electric motor?

A burnt-out electric motor can be fixed by way of a complete rewind. In some cases, it’s more prudent to replace a small motor than give it a rewind. 

Why does a motor need rewinding?

Motors need rewinding in order to regain their previous efficiency, or even to bring back failed motors so that they can give a few more years service. Motors that have burnt also benefit from rewinding to bring them back to working condition.

Get in touch today!

We offer a free local collection and delivery service for all motor repairs, as well as free testing and quotation, and a Full 12-Month Parts and Labour Guarantee.

Give us a call on 0114 204 4831 or send us a message using the form below if your motor is underperforming, or you think you it might need repairing.

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Tom Beatson is the Managing Director of Beatson Fan and Motors, a business that has been successfully passed through my family for four generations. Tom has made it his goal to grow the business and serve Beatson's customers, whilst upholding the values that have seen it through over 90 years of trading: Honesty, Trust, Respect, Proactivity and Pride. Since 2017 he has served as a representative of the North of England for the Association of Electrical and Mechanical Trades Council.