Repairing Guides

how to repair a dc motor

by Vinnie White Published 2 years ago Updated 2 years ago
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Repairing a Small DC Electric Motor

  1. Clean It. If it needs it clean it with scotchbrite and soap to remove any corrosion and goo it doesn't matter that it gets wet you're going to ...
  2. Take It Apart. Place a small blunt blade between the drive gear and casing and leaver the gear off. ...
  3. Clean and Examine. ...
  4. Repairs. ...
  5. Reassembling. ...
  6. Other Motors 1. ...
  7. Larger Motor. ...

Full Answer

How do you troubleshoot a DC motor?

• Proper connection of motor: If the motor leads aren’t connected directly to the drive terminals, any device external to the output of the drive can be a potential suspect. Most DC motors have an armature resistance in the 10s of ohms or less. Measure the motor resistance right at the drive.

How to repair small DC motor at home?

How to repair DC motor in 3 minute,DIY How to repair dc motor brushes is shown in this video..if you have those motors and if they aren't working because of ...

How to clean DC motor?

Tools/Supplies Needed:

  • tooth brush or nylon brush
  • electrical contact cleaner
  • safety glasses
  • rubber gloves
  • drill with larger chuck
  • 600 grit aluminum oxide sandpaper
  • plastic scriber
  • file
  • razor knife
  • cutting blade

How to upgrade DC motor?

Users should upgrade their DC drives when:

  • You want to save money, as when the DC drive replacement costs less than AC system replacement throughout the HP range;
  • The existing DC motor is in decent shape, and spares are readily available;
  • Your situation requires fast upgrade with minimal downtime.

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Can a DC motor be repaired?

DC motors often have to have field coils and armatures rewound and insulated. In some cases, repairs can be made but, sometimes, rewinding is necessary to achieve acceptable motor performance.

How do you troubleshoot a DC motor?

0:301:41Troubleshooting a Brushed DC Motor - YouTubeYouTubeStart of suggested clipEnd of suggested clipAnother test that could be performed is to run the motor using a 9-volt battery connect the positiveMoreAnother test that could be performed is to run the motor using a 9-volt battery connect the positive terminal of the 9-volt battery to the positive terminal of the motor connect.

Why do DC motors stop working?

The most common cause of motor failure, and arguably the most difficult to overcome, is low resistance. Low resistance is caused by the degradation of the insulation of the windings due to conditions such as overheating, corrosion, or physical damage.

How do you service a DC motor?

In brief, a D.C. motor maintenance program (Table 1) begins with reviewing a motor's service history....Table 1: D.C. Motor Maintenance Program. 6.Wipe off dust, dirt, oil, etc.MonthlyTest field coilsSemi-annualTest armature windingsSemi-annualCheck electrical connectionsSemi-annual5 more rows

What is the most common cause of motor failure?

Winding insulation breakdown and bearing wear are the two most common causes of motor failure, but those conditions arise for many different reasons....Shaft imbalanceDirt accumulation.Missing balance weights.Manufacturing variations.Uneven mass in motor windings and other wear-related factors.

Can you fix a burnt out electric motor?

If an electric motor operates at too high a voltage, excess current flowing through the windings can cause them to become hot and burn out. While it is normally not practical to repair small, direct current (DC) motors that have burned out, other motors can be repaired by rewinding.

What can damage a DC motor?

High levels of humidity can cause corrosion within the bearing which causes increasing level of friction which has a growing effect on wear. This may damage the shaft and the bearings restricting the smooth rotating operation of the motor which can affect speed and torque.

How do you troubleshoot a motor?

0:159:26How To Troubleshoot 3 Phase Motor With A MultiMeter (3 ... - YouTubeYouTubeStart of suggested clipEnd of suggested clipCover.MoreCover.

What are the common fault in DC machines?

These faults include differential current, shorted armature windings, shorted field windings, and off magnetic neutral plane brush positions. To detect the various faults in DC motors, we must develop a methodology to properly differentiate normal operating conditions from those of fault operating conditions.

Are DC motors easy to maintain?

Once established, it is reasonably easy to control and maintain this. If this is not considered, when the brush gets to a critical length some erratic performance in the motor may be seen.

How do you clean a DC motor armature?

0:273:27DIY: How to Clean the Commutator of an Armature - YouTubeYouTubeStart of suggested clipEnd of suggested clipWww.keytime.com spray the contact cleaner on the commutator then agitate the surface with theMoreWww.keytime.com spray the contact cleaner on the commutator then agitate the surface with the toothbrush. This will remove any oils dust dirt or any other contaminants.

Which type of test is included in DC motor maintenance and repair?

Hopkinson's or Regenerative or Back To Back Test: Two identical DC shunt machines are coupled mechanically and tested. One of the machines is run as a generator while the other as a motor.

What can go wrong with a DC motor?

Let’s face it, there is a lot that can go wrong with a DC motor, but most of it involves fairly straightforward repairs, such as bearing replacement or a simple brush replacement. These repairs won’t take as long as a more complicated repair like an armature or field coil rewind. Keep in mind, however, that a fast repair isn’t always a good repair. Quality DC motor repair shops will work to track down not just what is wrong with your motor but what caused it to fail in the first place. This takes time, as does redesign for improved performance and careful quality testing. The extra time invented in repair will, in turn, result in significantly better downtime and much better motor performance.

What are the different types of DC motors?

The four types of DC motors are shunt wound motors, series wound motors, permanent magnet, and compound motors. Shunt motors are typically used for speed regulation made possible because the shunt field can be excited separately from the armature windings. Series motors generate excellent starting torque but don’t offer much in the way ...

Why is my commutator burning?

Marking and burning on the commutator can indicate issues with the DC motor. Slot bar marking can be seen as every other or every few commutator bars being darkened and discolored. This is from an uneven current distribution or a bad armature winding. Burning of the commutator bar edges indicated that there is incorrect brush alignment, bad interpoles (if applicable), incorrect brush grade, or even low spring pressure. You may also see copper drag happen which looks like you smeared the copper of the commutator with the brushes. This is due to excessive heat that softened the commutator surface. This is an indicator of a potential larger issue.

How do armature coils work?

The ends of the armature windings are connected to a commutator which allows each of the armature coils to be energized in turn via carbon brushes (except in the case of a brushless motor, which makes use of electronics to achieve the same effect).

Why does my commutator brush groove?

This is usually caused either by arcing due to an incorrectly installed brush (low spring pressure) or the use of the wrong type of brush (abrasive).This can also be caused by low humidity and temperature.

What happens if a DC motor brush is worn?

The carbon brushes on a DC motor will wear over time and will eventually need to be replaced. Worn brushes can cause loss of power to the armature, damage to the armature winding, and damage to the commutator. Premature motor brush wear can result from incorrect installation as well as issues with the windings, voltage surges, overloading, and sparking. An added complication from carbon brush wear is the generation of carbon dust which can lead to grounding of the field coil or armature winding.

What causes motor brush wear?

Premature motor brush wear can result from incorrect installation as well as issues with the windings, voltage surges, overloading, and sparking. An added complication from carbon brush wear is the generation of carbon dust which can lead to grounding of the field coil or armature winding.

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