Allen Bradley Servo Motor Repair

Allen Bradley Servo Motor Repair VS. Replacement

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Allen Bradley servo motor repair is less expensive than Allen Bradley servo motor replacement. Trained technicians should perform Allen Bradley servo motor repair. Technicians undergo unique testing procedures on Allen Bradley servo motors that are dependent upon their model, features, operations, and prints. Allen Bradley servo motor repair should initially be inspected for cosmetic damage. Taking photos of the servo motor prior to further processing is suggested.

Servo Motor nameplate data and preventative maintenance info should be collected by the repair technician and safely stored for future reference. Once these initial steps are complete, the servo motor should be meter tested before test running on a control panel; Meter testing prevents further damage to parts, winding, and insulation. The servo motor should then beconnected to a test stand to check EMF (electromagnetic frequency), encoder or resolver feedback, and commutation alignment; These standard tests are to ensure functionality oncethe motor is installed forproduction. Servo motors also need to be tested with an oscilloscope to create an operation print. Once an operation printout is generated, a technicianwill check for connection issues, magnet failure, winding failure, and perform a 100% component test.

Once the technician finishes making repairs, they will then reassemble for final testing. During the final test procedure, technicians should connect the motor to an inverterwith and without a load. Running the servo motor on an inverter is to ensure complete functionality. Testing with an inverter also allows verification that the servo can operate at full voltage and withstand full load amps of motor specifications. Repair shops should work closely with all servo motor manufacturers. Working closely with servo motor manufacturers allows for access to servo motor data sheets. Repair technicians use data sheets to ensure that the servo motor performs equal to, orbetter than, the original manufacturer standards.

Most repair shops offering Allen Bradley servo motor repair do not even perform the repair in their facility. Instead, these repair shops outsource the repair to a third party such as Precision Electric. Using a third party repair shop is risky, more expensive, and has a longer lead time than going directly to the repair source.Allen Bradley servo motor repair from Precision Electric includes a 12 month in-service warranty. For Allen Bradley servo motor repair and replacement quotes, contactPrecision Electric.

Indramat Servo Motor Repair

Indramat Servo Motor Repair

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Indramat servo motor repair is less expensive than Indramat servo motor replacement. Indramat servo motor repair should only be performed by an electrical technician with training and experience.Most Indramat servo motors have unique testing procedures dependent upon their model, features, operations, and prints; But the general process is performed by a technician who follows standard test procedures. Technicians performing Indramat servo motor repair should go through an extensive evaluation process to ensure nothing is overlooked. Servo motor repairs should be initially inspected for cosmeticdamage and taking photos prior to further processing is suggested.

All nameplate and preventative maintenance info should be collected by the repair technician and safely stored forfuture reference. Once these initial steps are complete, the Indramat servo motor should be meter tested before test running on a control panel; Meter testing is to prevent further damage to parts, winding, and insulation. The servo motor should then be connected to a test stand to check EMF (electromagnetic frequency), encoder or resolver feedback, and commutation alignment; These standard tests are to ensure functionality once the motor is installed into production.Servo motor repairs also need to be tested with an oscilloscope to create an operation print. Once an operation printout is generated, the technicianwill check for connection issues, magnet failure, winding failure, and perform a 100% component test.

IndramatServo Motor Repair – Steps

  • Visual inspection of cosmetics
  • Take photos of unit
  • Gather nameplate data and shaft dimensions
  • Inspection of all electrical and mechanical servo motor parts
  • Re-magnetize magnets when necessary
  • Re-manufacture outputflange using original flange and factory dimensions
  • Repair or rewind servo motor windings, insulation, connections
  • Steam clean and bake
  • Replace brush holder and brushes (or repair brush holder if obsolete)
  • Grounded to electrical testing
  • Surge testing of everywinding to at least 1500 volts
  • Armature bar to bar test; to determine any shorts or opens within the winding
  • Servo motor alignment
  • Installation of high-grade sealed bearings
  • Installation of double lip seals in the front flange
  • Replacement of all old seals, O-rings, gaskets and connectors
  • Two part epoxy coating for an added protection

Once testing is complete, the servo motor technician reassembles the unit for final testing. During the final test procedure, techniciansshould connect the motor to an inverter drive with and without a load. Running the servo motor on an inverter is to ensure complete functionality beforereturning to customer. Final testing of servo with an inverter also allows verification that the servo motor can operate at full voltage and withstand full load amps of the motor specifications.It’s also suggested that repair shops work closely with all servo motor manufacturers. Working closely with servo motor manufacturers allows foraccess todata sheets that are needed to ensure that the the servo motor performs equal to, or better than, the original equipment manufacturer standards.

Some repair shops only require technicians to perform a few of these procedures but all of them are suggested by Precision Electric. Most repair shopswho offer Indramat servo motor repair do not even perform the repair in their facility; Instead, they outsource the repair to a third party such as PrecisionElectric. Precision Electric recommends technicians who areinvolved in repair decisions, verify thatthe company you’re sending equipment to is the same company who performs the repair. Using a third party Indramat servo motor repair shop is risky, more expensive and has a longer lead time than going directly to the repair source.

Servo motor repairs performed by Precision Electric includes a 12 month in-service warranty. The PrecisionElectric in-service warranty begins the day the servo motor is put into production and ends 12 months later.

For more information on Indramat servo motor repair and replacement, contact Precision Electric.

Servo Motor Repairs

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Servo motor repairs areless expensive and quicker than servo motorreplacements.Servo motorrepairs should be taken with extreme caution and only be performed by technicians who have training and experience to work with electrical equipment. Most companies who offer servo motorrepairs do not even perform the repair in their facility; instead, these companies outsource the repair to a third party such asPrecision Electric. Precision Electric always receives servo motorrepairs from companies who offer servo motorrepair services. Third party repair companies take longer to return equipment to their customers and third party repair companies mark up the repair cost to their customers. Precision Electric recommends verifying that the company offering repair services is the company actually repairing the equipment.

Servo motor repairs should always go through an extensive evaluation process to ensure nothing is overlooked.The servo motor should be connected to a test stand to check back emf, encoder or resolver feedback, and commutation alignment to ensure functionality once the motor is installed into productions. Servo motor repairs need tobe tested with an oscilloscope andonce an operation printout is generated, the technician will check for connection issues, magnet failure, winding failure, and 100% component testing. Servo motor repairs at Precision Electric are initially inspected for cosmetic damage and then they are meter tested before test running on a control panel. Most servo motor repairs have unique testing procedures dependent upon the manufacturer operations and prints, but the general process follows standard testprocedures.

It’s also necessary for Precision Electric to work closely with all servo motor manufacturers. Working closely with servo motor manufacturers allows Precision Electric access to technical data sheets that are neededto ensure that the the servo motor performs optimally prior to shipping the repaired unit back to customer.

Precision Electric standard servo motor repairs are subject to:

  • An inspection of all electrical and mechanical servo motor parts.
  • Re-magnetize magnets when necessary,
  • re-manufacture servo motor flange using the originalflange and factory dimensions
  • repair or rewind servo motor winding, insulation, connections, steam clean and bake
  • replace brush holder and brushes (or repair brush holder if obsolete)
  • test to confirm there are no grounded electrical parts in the servo motor.
  • all AC stators are surge tested to at least 1500 volts This ensures that the insulation and windings will withstand the loads put on the servo motor when running on a machine.
  • after the bakin g process, DC Servo motor armatures go through a bar to bar test. This test will show if there are any shorts or opens in the winding.
  • servo motor alignment
  • High-grade sealed bearings
  • Double lip seals in the front flange
  • Replace all new seals, O-rings, gaskets and connectors
  • Two part epoxy coating for an added protection

After servo motor repairs and preliminary testing are complete, the servo motor is reassembled for final testing. Servo motor repairs are not complete until after final testing procedure is performed. During the final test procedure, servo motors should be connected to an inverter drive with and without a load, to ensure functionality before returningto customer. Final testingalso allows verification that the servo motor can operate at full voltage and withstand full load amps of the motor specifications.

Servo motor repairs should only be performed by facilities that work closely with all servo motor manufacturers so that the newest servo drives are being used in conjunction with theircorresponding servo motors.Precision Electric recommends all manufacturers keep spare servo motors on crucial production lines. Keeping a spare can minimize downtime and prevent production losses while repair services are being processed. Servo motor repairsperformed by Precision Electric includes a 12 month in-service warranty. The Precision Electric in-service warranty begins the day the servo motor is put into production and ends 12 months later.

For pricing on servo motor repairs andservo motorreplacements, contact Precision Electric.

 

Brushless Servo Motors

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Brushless Servo MotorsBrushless servo motors are used when an industrial application requires high performance and precise speed regulation. Brushless servo motors are manufactured with a designated controller known as a servo drive or servo driver.Brushless servo motors use position feedback to precisely regulate motor control by being paired with an encoder. Encoders measure a brushless servo motor’soutput shaft position which is compared to the command position. When the brushless servo motor output shaft doesn’t match the demand signal, an error signal is sent to the servo motor controller; the controller adjusts accordingly and sends a signal back to the servo motor until the demand position is met. Brushless servo controllers (servo drive, driver, etc.) are never included in the base price of the brushless servo motor. Brushless servo motor systems can be expensive but the cost is justified with optimal manufacturing processes via precise speed regulation.

Brushless Servo MotorsBrushless servo motors output more torque than brushed direct current motors. Brushless servo motors aren’t as loud during operation than brushed direct current servo motors. The lifespan of brushless servo motors exceeds than that of a brushed direct current motor because there aren’t brushes or a commutator to maintain. The idea behind brushless servo motors was to be able to integrate control function of the servo motor with industrial electronic components and personal computers; and to precisely position machines in manufacturing processes. Some manufacturers use brushless servo motors in explosive and dirty environments because brushless servo motors are entirely closed and sealed to prevent dust or sparks to reach the servo motor parts.

How We Repair Servo Drive Servo Motors Professionally

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how-to-repair-servo-drive-servo-motors-professionally

We repair and warranty all major AC and DC Servo Motors and Controllers, feel free to call now at 1-877-625-2402 for a free quote orfill out the Servo Motor and Drive Quotation Form. For those of you looking to repair the drive yourselves, our procedure for professional repair is listed below.

For those interested in repairing servo motors and servo drives, it is important to note the extreme care that should be taken prior to conducting any disassembly of a servo motor or servo drive unit.

All servo motor and servo drives are mechanically calibrated between multiple facets of the unit to ensure the proper positioning of the device when it is commissioned. Failure to properly dis assemble a servo motor or drive can actually cause the unit to become unusable in the future.

The inner workings of servo motors and servo drives are both separate, and thus they should be treated separately. This particular article focuses primarily on troubleshooting the servo motor that is connected to the servo drive.

Servo motors are specifically designed with what is known as “feedback” capabilities so that the servo drive can maintain positioning of the motor within fractions of an inch, and many times even more accurate when necessary. Servo motors are specifically designed to withstand high amounts of holding current as well as extremely fast start stop procedures so that accuracy can be maintained at all times.

This feedback connected to a servo motor often comes in the form of an encoder or resolver, depending on the type of encoder or resolver you might have, troubleshooting your servo motor may be impossible. In many cases, manufacturers such as Allen Bradley, or Rockwell, implement a proprietary resolver or encoder feedback so it cannot be repaired without their diagnosis and repair tools. Regardless, there are many more aspects to a servo motor that can go bad other than the encoder or resolver – so it is best to start at those places.

The following is the procedure used by Precision Electric illustrating how to repair servo drive servo motors professionally.

Step 1: Take Notes

This is often a subject that is passed by many individuals who are attempting to repair industrial equipment. When a unit first hits our bench we make note of many important aspects of the equipment including, but not limited too:

    1. Manufacturer
    2. Serial Number
    3. Reason for Service
    4. Urgency (Rush Overtime or Standard)
    5. Visual Inspection of External Device

Step 2: Check The Shaft

It is important at this point to establish whether or not the servo motor shaft has been bent, damaged or broken. If this is the case, a new shaft may need to be ordered or machined in order to recommission the unit. In some cases, a bent shaft cannot even be replaced and this can quickly become a quote for replacement.

A bent shaft on a servo motor can cause extreme wear to the device over time due to vibration and heat. A bent shaft can also cause slip on a gear box and loss in positioning resulting in unexpected faults from the servo drive. You may need to use a caliper to establish the proper positioning of the shaft within the closest accuracy possible.

Step 3: Check The Encoder and Motor Cables

Hopefully the customer sent the communications cable with the unit so you can test the pin-out of the cable to ensure all of the wiring has a strong signal. In instances such as these, you may need to pull up pinout information from the servo motor manufacturing website to ensure you are testing the appropriate cables. In many cases, an encoder cable with have a pin for each channel of A, A not, B, B not, Positive Voltage and Common.

In some cases it will also have a Z and Z not pulse as well as a shield. Of course, not all customer are able to send the cable with the unit because they sent you a spare to repair – if that is the case you are really left with no other choice than to move on to the next step. Finding a bad cable early on is a great way to solve servo motor feedback issues without ever even requiring disassembly of the servo motor.

For the motor cable, you are looking at 3 separate phases, 2 armature wirings and sometimes commutation wiring. Using your meter, test the end of each cable to ensure there are no shorts between any of those connections.

Step 4: Check The Bearings

The shaft coming out of the servo motor should rotate freely with little resistance. This is assuming you have actually disconnected the cables from the original servo drive. The drive often causes resistance when rotating the shaft if it is connected to the servo drive through the motor cables.

If there is “bouncing” when attempting to rotate the shaft then it is likely due to a short within the motor or a bearing beginning to fail. In either case, it is bad and the servo motor will need to be disassembled for further diagnosis.

Step 5: Test The Motor For Shorts

This step is essential to further diagnostics. At this point you need to test the motor to ensure there are no shorts within it. Using your meter, you will want to test from phase to phase to ensure the connections are open. Do the same with the armature connections. There should be no shorts between them. If you find a short at this point it is likely the cause of the failure.

Servo motor shorts can be caused from a variety of reasons including contamination, overheating and wear and tear – the only real way to find the source of the short is to disassemble the unit and establish the cause of failure.

Step 6: Rotate the Motor

Assuming the prior tests have all passed, apply a small voltage starting from 0 volts to the armature winding of the servo motor. Slowly increase this voltage using your variable power supply until the shaft begins to turn. It is at this point you can further evaluate whether there is unnecessary vibration of the servo motor during rotation or whether the shaft appears to wobble or “bounce” due to a bent shaft or bad bearing.

In any case, rotating the motor prior to disassembling it is a good idea if it is possible – this will let you know that the servo motor at least functions on some level prior to establishing the original cause of the failure.

Step 7: Contact the Customer

If everything has tested healthy at this point it may be a good idea to contact the customer and get more details as to the original cause of failure. It is quite common with servo motor and servo drive applications that the cause of the failure was external to the motor itself. The servo motor often was doing what its job was intended to do, stop within a fraction of an inch of inaccuracy and fault.

Most people do not realize that an outside application change or environmental change can cause fluctuations in the configuration of the servo motor that can cause faults. It is also important to establish whether or not the servo motor was properly tuned for the application to begin with. Sending a field service tech and getting the servo motor properly tuned may cause the issue to go away.

Step 8: Carefully Disassemble The Servo Motor

When we say carefully, we mean carefully. You should mark the location of every detached piece with a punch to or file to ensure you reassemble the unit exactly as it was assembled. Failure to do this will often cause the servo motor to produce exceeding level of vibration which can cause further failures or not function at all. It is also sometimes wise to take photographs as you are disassembling the unit so you have a log of how the servo motor looked prior to each phase.

This section cannot be emphasized enough, as you remove more and more pieces of the servo motor take a closer visual inspection of each element within the motor including the commutator, armature, shaft and brushes. Try to locate any possible cause of failure before continuing to disassemble the drive. The sooner you find the cause of failure at this point the better, as it means less reassembly is required.

Once you have established the cause of failure your response will depend on both the manufacturer of the servo motor and the original cause. In many causes, certain brands will not allow you to purchase parts for their servo motors and a replacement may be required. There are certain aspects of a servo motor that can be replaced or repaired by third parties such as the armature winding or brushes.

Step 9: Send a Tech

If the customer cannot establish failure on any other aspect of the machine and the servo motor appears to test fine and be in good shape after disassembly, then it may be necessary to send a field service technician on site to establish cause of failure.

Our field service techs are trained to troubleshoot any issue ranging from standard AC Motor Speed Controllers to advanced robotics and PLCs. They are trained to establish cause of failure as quick as possible.

Conclusion:

Precision Electric has used these techniques over the past 20 years to establish one of the best reputations for the industrial service industry. These methods for testing servo motors have been well established and have resulted in the repair or replacement of thousands of industrial servo drive servo motors.