Annual Electric Motor Checklist for Reliability

December 30, 2024/by Lynn Dreisilker

The New Year’s Resolution Guide to Your Motors

As we step into the new year, it’s the perfect time to reflect on the health and readiness of your operations. Electric motors and their ancillary parts are critical to keeping your business running smoothly, yet they’re often taken for granted until something goes wrong. This year, let’s resolve to take a proactive approach to maintaining these essential assets. Here are some key areas to review and optimize:

1. Do You Have the Right Spares on Hand?

Unexpected motor failures can lead to costly downtime. Having a spare motor ready can make all the difference in maintaining continuity. But how do you know when you need a spare? Our guide provides actionable insights to help you decide when investing in a spare is the right move for your operations.

In addition to keeping spare motors on hands, you may want to evaluate keeping spare parts on hand. These parts may include bearings, pulleys, or specialized parts like encoders. We keep a large stock of spare parts on hand for the hundreds of repairs that we conduct every month. Furthermore, we keep a stock of spare parts for different industries such as the Machine Tool and Printing industries. Make sure that you store these parts properly. Below we show a picture of rotors for servo motors that are wrapped to prevent dust and other contaminates from impacting the material.

Spare Parts for Motors

2. Are You Storing Your Spare Motors Properly?

Having a spare motor is one thing, but improper storage can render it unusable when you need it most. Factors like temperature, humidity, and physical protection play a critical role in extending the life of stored motors. Learn how to store electric motors properly to ensure they’re ready for action. We keep a large inventory of spare motors at our headquarters for the Machine Tool and Printing industries. These motors are wrapped and stored in a humidity, climate controlled environment.

spare motors in storage

3. Is Your Preventative Maintenance Schedule Up to Date?

Preventative maintenance is the cornerstone of reliable motor performance. Regular inspections and servicing can identify issues before they become costly problems. This blog outlines the benefits of a consistent maintenance schedule and how it can save you time and money.

For facilities with DC motors, there are specific maintenance needs to consider, such as brush inspections and replacements. Check out our detailed guide to ensure your DC motors are in peak condition.

4. Are You Installing and Maintaining Belts Correctly?

Belt-driven systems are common in many operations, but improper tension or installation can lead to inefficiency, wear, and failure. Learn how improper belt tension affects your belt drive system and discover common belt problems that you can address proactively.

5. Have You Scheduled Infrared Analysis?

Infrared inspections are a highly effective way to identify potential issues with your equipment before they escalate. Many property insurance companies favor facilities that conduct regular infrared analysis, so it’s worth discussing this with your insurance provider. Explore the benefits of infrared inspection and consider scheduling this service as part of your annual maintenance plan.

Infrared Inspection

6. Are You Leveraging Vibration Analysis?

Vibration analysis can be a powerful tool in predicting motor maintenance needs or determining when a motor requires repair or replacement. Regular vibration checks can detect imbalances, misalignments, or bearing issues before they lead to significant downtime. We work with our customers to create tailored schedules—whether quarterly, monthly, or bi-annually—to suit their operational demands. Learn more about vibration analysis and how it can benefit your facility.

Start the Year Right

By addressing these key areas, you can set the foundation for a smoother, more efficient operation in the year ahead. Let’s make the new year where we prioritize reliability and efficiency for electric motors and their supporting systems. If you have any questions or need assistance with your motor maintenance strategy, don’t hesitate to reach out. Here’s to a successful and proactive year ahead!

Electric Motor Core Loss Testing

September 19, 2024/by Lynn Dreisilker

Core loss testing is a vital yet often overlooked step in electric motor maintenance and repair. By accurately measuring power loss within the motor’s core, this test helps identify underlying issues that can compromise efficiency, increase operating temperatures, and shorten the motor’s lifespan. In this blog, we’ll explore the importance of core loss testing, the methods involved, and how it can help ensure your motors are running at peak performance, saving you time and money in the long run.

What is a motor core?

The core of an electric motor plays a fundamental role in its operation, serving as the foundation for the stator windings and providing the magnetic circuit necessary for converting electrical energy into mechanical motion. The core is made of stacked laminations of electrical steel, must maintain its structural integrity to support the magnetic flux generated during motor operation. Any damage or distortion to the core, whether from improper stripping methods like burnout ovens or other factors, can compromise the motor’s performance. Core integrity directly impacts the motor’s efficiency, as any disruptions in the magnetic circuit can lead to increased core losses, reduced power output, and decreased overall efficiency. Therefore, preserving core integrity through Motor Safe Stripping is essential for ensuring the optimal functioning of electric motors in various industrial and commercial applications.

MotorSafe lamintions vs Burnout Oven laminations

On the left, you see a lamination stack in a motor’s core after Dreisilker performed its MotorSafe Repair Method to strip the windings. On the right, you can see a lamination stack after burning out the windings. The Motor Safe Stripping Method (left) maintains the core’s integrity.

What is core loss testing?

Core loss testing is a diagnostic procedure used to evaluate the efficiency and performance of the stator core in electric motors by measuring the losses incurred during operation. These losses primarily consist of hysteresis losses, which occur due to the magnetic material’s resistance to changes in magnetization, and eddy current losses, which are induced currents that flow within the core material itself, generating heat and wasting energy. During core loss testing, technicians apply a specific voltage to the motor and measure the resulting current, allowing them to calculate the core losses under various operating conditions. This testing is essential for identifying potential issues such as overheating, insulation degradation, or structural damage within the core, which can adversely affect the motor’s efficiency and reliability. By conducting core loss testing, technicians can ensure that the motor operates at optimal performance levels, thereby extending its lifespan and reducing energy consumption.

Our experienced Winder core loss testing a motor during the repair process.

How core loss testing can impact reliability:

Distortion of the core and the presence of hot spots in an electric motor can significantly impact its efficiency and overall performance. Core distortion, often caused by uneven heating or excessive temperatures during processes like burnout oven stripping, can lead to misalignment of laminations and structural irregularities within the core material. This distortion disrupts the magnetic circuit essential for motor operation, resulting in increased core losses and reduced magnetic efficiency. Hot spots, localized areas of overheating within the core, can further exacerbate efficiency issues by causing thermal stress, insulation breakdown, and potential damage to the core material. These hot spots create inefficiencies in the motor’s operation, leading to energy losses, decreased power output, and compromised reliability.

Infrared image of an electric motor’s core. It shows hot spots which would lead to inefficiencies during operation.

At Dreisilker, we utilizing our MotorSafe Stripping method to safely remove motor windings during a repair. Through proper temperature control, insulation removal techniques, and post-stripping inspections is crucial to maintaining optimal motor efficiency and performance. During the repair, if we find that the motor’s core has hot spots, we consult our customers on whether it is recommended to replace the core.

Overall, core loss testing is a critical diagnostic tool in electric motor repair. By testing and addressing core losses, we can ensure the reliability, efficiency, and longevity of electric motors, ultimately leading to cost savings and improved performance. Learn more about our full rewinding services to see all of the steps within a rewind.

Environmental Impact of the Burnout Oven Electric Motor Repair Process

June 5, 2024/by Lynn Dreisilker

It is increasingly important to understand how our decisions impact the environment and energy consumption in every day life. These decisions are also important for when you are selecting your electric motor repair partner. Understanding the different methods of electric motor repair and how they impact your electric motor’s efficiency and reliability are crucial. In this article, we will walk you through how the burnout oven electric motor repair process impacts your motors and review how Dreisilker’s MotorSafe Repair method differs.

What is the burnout oven electric motor repair process?

The burnout stripping method is a long-established technique utilized in the repair of electric motors to remove insulation and varnish from stator windings in preparation for rewinding. This process involves placing the stator in a specialized oven set to a high temperature, typically around 650°F, for an extended period, often exceeding eight hours. The intense heat effectively turns the insulation and varnish materials on the windings into ash, facilitating their complete removal. While this method is highly effective in preparing the stator for the application of new windings, it carries potential risks and challenges. These include possible damage to the stator core and frame from excessive heat, environmental concerns due to the release of gasses and byproducts, significant energy consumption, and the generation of waste materials that require proper disposal.

A 100HP Motor after the Burnout Process

How core integrity impacts electric motor efficiency:

The core of an electric motor plays a fundamental role in its operation, serving as the foundation for the stator windings and providing the magnetic circuit necessary for converting electrical energy into mechanical motion. Core integrity is paramount in ensuring the motor’s reliability, efficiency, and longevity. The core, typically made of stacked laminations of electrical steel, must maintain its structural integrity to support the magnetic flux generated during motor operation. Any damage or distortion to the core, whether from improper stripping methods or other factors, can compromise the motor’s performance. Issues with the core can lead to increased core losses, reduced power output, limited lifespan, and decreased overall efficiency.

To maintain optimal motor performance, core loss testing is a critical aspect of electric motor repair and maintenance. This process involves assessing the core losses in the stator core to evaluate the motor’s efficiency and performance. By measuring core losses, which include hysteresis and eddy current losses within the core material, technicians can identify any abnormalities or damage that may have occurred during the repair process, such as stripping and rewinding. Core loss testing ensures that the motor operates within optimal efficiency levels and can detect issues like core overheating, insulation breakdown, or structural damage. Conducting thorough core loss testing as part of the repair procedure allows technicians to verify the integrity of the stator core and make informed decisions regarding any necessary corrective actions to maintain the motor’s efficiency and longevity.

Considerations for use of the burnout oven motor repair process:

One of the critical factors affecting core integrity during the burnout oven process is temperature control. Excessive temperatures can lead to thermal stress and damage to the stator core and frame. It is essential to adhere to recommended temperature settings (around 650°F) and duration to prevent overheating and potential core damage. If you are working with a repair shop that utilizes the burnout method, it is important to inquire about their quality procedures for temperature control. Through our many years of experience, we have found that many repair shops may ignore the 650°F guideline and increase the temperature to expedite the process. While this might speed up the turnaround time, it can also negatively impact the motor’s efficiency.

Another significant consideration is the potential for core distortion and hot spots within the motor. Core distortion, often caused by uneven heating or excessive temperatures during the burnout process, can lead to misalignment of laminations and structural irregularities within the core material. This disruption of the magnetic circuit essential for motor operation results in increased core losses and reduced magnetic efficiency. Additionally, hot spots—localized areas of overheating—can further exacerbate efficiency issues by causing thermal stress, insulation breakdown, and potential damage to the core material. These inefficiencies lead to energy losses, decreased power output, and compromised reliability. Therefore, careful management of the burnout stripping process is crucial to minimize these risks and ensure optimal motor performance.

Alternatives to the burnout oven:

Recognizing the challenges and environmental concerns associated with the burnout oven method, we at Dreisilker have developed an alternative solution known as the MotorSafe Repair process. In a comprehensive study, we compared the burnout oven method with our MotorSafe approach, highlighting the significant advantages of our method in terms of both performance and environmental impact. Read more on the study here: MotorSafe vs Burnout Method Comparison

The MotorSafe Repair process prioritizes the protection of core integrity, minimizes energy consumption, and reduces the release of harmful emissions. In the following sections, we will delve into the specifics of the MotorSafe Repair process, discuss our study’s findings, and explore the environmental benefits that make MotorSafe a superior choice for electric motor repair. Additionally, we will refer to an article that further explains how the MotorSafe method positively impacts the environment, underscoring our commitment to sustainability and efficiency in motor repair.

Laminations after the MotorSafe Repair Method (left) vs the Burnout Oven Method (right)

Environmental Impact of the MotorSafe Electric Motor Repair Process

May 29, 2024/by Lynn Dreisilker

The MotorSafe Electric Motor Repair process plays a important role in promoting environmental sustainability and aiding companies in achieving their green goals. By focusing on efficiency and precision, our repair method focuses on a motor’s efficiency, optimizes motor lifespans, and enhances resource efficiency. As a result, MotorSafe Repair ensures the efficiencies of motors to optimize their energy consumption for critical operations. The MotorSafe Repair process can have a positive impact on the environment and help companies meet their sustainability goals in several ways:

Focus on Energy Consumption: The biggest impact an electric motor repair service center can have on a motor’s energy consumption is within the rewinding process. If a motor is found to need a rewind, it is important to understand how the windings are stripped. With our MotorSafe Repair Method, we measure a motor’s core loss before and after stripping. The core loss testing process checks for overheating, damage, and hot spots within the motor’s core. A motor that does not pass our core loss testing would not run efficiently, leading to possible overheating and a shortened life span. In this case, we would recommend replacement of the core (when possible) to avoid efficiency issues. After the core loss testing, we proceed with our MotorSafe Stripping Method which safely removes the coils from the motor – ensuring no further degradation to the motor’s core. In contrast to MotorSafe Stripping, the industry standard Burnout Incineration method (used by other electric motor repair facilities) can introduce electric motors to considerable, damaging heat. At Dreisilker, we always conduct the core loss test before and after the stripping process to confirm the motor’s core condition.

To learn more about the environmental impact of electric motor repair, read our study: Burnout Oven vs MotorSafe Repair

Core loss testing a motor

Testing a motor’s core.

Materials Used in the Repair: A critical part of a motor’s efficiency includes the materials used in the repair. There are many standards imposed by the National Electrical Manufacturers Association (NEMA) that impacts how motors are manufactured and how we repair our motors. The standards created by NEMA can dictated the type of copper wire, the insulation paper, the varnish, and etc. Our skilled rewinding technicians examine the motor we received, its nameplate, and its data packs to understand what replacement material we need to use throughout the repair.

We use Class H wire in our rewinding method and we carry Class N rated varnish, which allows the windings to withstand higher temperatures. Furthermore, the varnish is hermetic rated which impacts the operations of compressor motors.

Taking Extra Steps: There are many ways how taking extra steps during a repair can impact the efficiency and longevity of motors. For example:

Crease and Cuffing: We use high quality slot paper that we crease and cuff for every slot. The cuff allows for mechanical rigidity of the windings, limiting vibration and increasing reliability. Read more here: The Basic Steps of an Electric Motor Rewind
Tying down slots: We tie down every slot during a rewind which helps aid the cuffs for mechanical rigidity. Most repair facilities and ever manufacturers take a short cut and tie down every other slot to save time. Read more here: The Basic Steps of an Electric Motor Rewind
Proper cool down: During the double dip and bake varnish process, we let the windings cool after curing in the oven before dipping them again in varnish. Allowing the motor to cool ensures the varnish adheres properly to the windings. If the motor is too hot, the varnish will become too viscous and run off the windings more easily. Read more here: 4 Types of Motor Winding Insulation Methods

Dreisilker Winding Components

Dreisilker’s rewind for a random wound motor.

Recycling: Dreisilker works with certified partners in order to recycle and dispose of materials from the electric motor repair process. Throughout a typical motor repair, it is possible for us to need to replace many components of the motor including bearings, coils, end bells, shafts and more. Our technicians are trained on how to sort and recycle these different types of materials. Sorting different resources enables us to collaborate with our partners to properly recycle materials, ensuring they can be reused. Like many other industries, we use solvents and chemicals within the repair process. We partner with chemical disposal companies so that we are limiting the environmental impact of these used chemicals.

In conclusion, the MotorSafe Electric Motor Repair process acknowledges the need for environmental sustainability and supports companies in meeting their green goals. By emphasizing energy efficiency, precision in repair techniques, and the use of high-quality materials, MotorSafe enhances motor performance and longevity. Our meticulous approach to rewinding, repairing, and material selection ensures motors operate optimally, reducing energy consumption and minimizing environmental impact. Additionally, our commitment to responsible recycling and disposal practices underscores our dedication to sustainability. By adopting the MotorSafe Repair method, companies can achieve greater operational efficiency while aligning with their environmental and sustainability objectives.

The Basic Steps of Electric Motor Repair

December 8, 2021/by Lynn Dreisilker

Electric Motor Incoming Documentation:

During electric motor repair, it is vital to document all nameplate information. Never allow someone to take off your nameplate! It’s a crucial part of your motor. We also clean parts and visually inspect the electric motor.

Measuring & Testing during Electric Motor Repair:

When we complete an electric motor refurbishment, we measure the motor’s components such as shaft runout, bearing journals, bearing housings, keyways, output shaft diameter, and more. Furthermore, we also conduct testing of the rotor conditions through a growl test and hot spot tests. At this stage during an electric motor repair, we test the windings through surge testing, phase resistance, insulation resistance megger, Hi-pot (AC destructive, DC non-destructive), and visually insect the electric motor winding.

Machining:

Depending on the condition of the motor, machining is a necessary part of the electric motor repair process. Our in-house machining department works on failed housing, repairing or manufacturing new shafts, and more. For electric motor shaft repair, we can weld and machine shafts, chrome and grind, make a new shaft, and straighten a shaft. We also ensure the proper material is selected and also heat treat material as necessary. Pro Tip: Watch out for some unacceptable practices such as punching/peening of housings, gluing in bearings, JB welding, glue or stubbing).

Dynamic Balancing for Electric Motor Repair:

Dreisilker’s electric motor repair shop follows and exceeds ISO 1940-1 standards for repair on all rotating apparatus. Balancing is an important step in the electric motor repair process, as it greatly impacts the longevity of the motor repair.

Electric Motor Stripping:

The stripping of your windings is a very important part of the electric motor refurbishment process. Ask your shop how they strip your windings. Dreisilker utilizes MotorSafe stripping that protect the motor and its laminations.

Electric Motor Rewinding:

Electric motor rewinding is very detail oriented and can impact the longevity of your electric motor. We rewind motors back to OEM specifications or greater, using the proper wire selection and high quality materials such as phase paper, insulation, and slot liners. Pro tip: Ask your shop if they use automated coil winding machines. Dreisilker uses automated machines for the best windings possible. Check out our blog “The Basics of an Electric Motor Rewind”

Electric Motor Varnishing:

After rewinding, an electric motor is varnished to electrically insulate the winding and to mechanically protect it from contamination & vibration. We use the following methods: Dip & Bake, Vacuum Pressure Impregnation, Trickle Varnishing, and Ultra Seal. Check out our blog on 4 Types of Motor Insulation Methods to learn more.

Assembly & Testing:

After winding and varnishing, the electric motor is re-assembled and tested during our quality control process.

Painting:

The final step of the electric motor repair process is painting. We paint every motor that has been repaired and follow any request from our customers. Furthermore, we ensure that the nameplate is secured and any necessary labeling is on the motor.

Considerations for Water Cooled Injection Molding Machine Motor Repair

July 1, 2021/by Lynn Dreisilker

The plastic industry relies on injection molding machines to produce part after part. To endure the high demand, the motors on injection molding machines are manufactured to withstand extreme environments. The motors are water cooled and are unique compared to a standard motor. When repairing these motors, you should consider how your repair shop strips the motor of its coils, how it is rewound and how the windings are varnished.

Disassembled Water Cooled Injection Molding Machine Motor

Disassembled Water Cooled Motor

The stripping methods used by standard motor shops can be detrimental to water cooled motors. These shops use the Burnout Oven method where the motors are placed in an incineration oven to heat up the varnish to make the coils pliable. Burnout oven temperatures exceed 680°F which compromise the integrity of the core with frame damage & distortion. While distortion of any motor housing is unacceptable, a unique problem with water cooled motors is the warping of the motor housing causing a leak in the water jacket. A faulty water jacket can allow the coolant to leak and contaminate other components of the motor.

Similar to the issues with a distorted water jacket, water cooled motors may have rubber o-rings that are susceptible to the high heat of the Burnout Oven. When introduced to high temperatures, the o-rings can melt causing leakage of the coolant. This leakage can contaminate the windings, bearings, electronic components and etc. This contamination can result in a slew of problems including but not limited to damaged bearings, imbalance of rotating equipment, and breakdown of insulation. To learn more about the effects of contamination and how to prevent it, read our article Electric Motor and Generator Failures from Contamination.

Unlike other motor repair shops, Dreisilker uses its MotorSafe Stripping method in place of the Burnout Incineration Method. In our MotorSafe Stripping method, we gently warm the outside diameter of the laminations to 400 degrees F with induction or non-contact natural gas. Once heated, we hydraulically remove coils preserving 3 phase groups for data. Our method of motor stripping protects the motor housing and specialized elements of a motor such as a water jacket or o-rings.

After stripping of a motor, rewinding the motor is a critical step of the repair process. We make sure to wind the motors back to OEM specifications or better using computer-controlled technology. The original wire size and wiring data are recorded so that we can replicate the motor’s winding with uniformity and accuracy. Other shops may change specifications, substitute with inferior materials, or modify the original design.

When a motor is rewound, the windings need to be varnished to protect the motor windings from contamination and ensure electric conductivity. The typical repair shop method for varnishing a motor is the dip and bake method. While we use this method for common motor applications, we trickle varnish water-cooled motors to match the OEM standards (for water-cooled motors).

Trickle varnishing is accomplished by connecting the windings to a rotating table and using electrical resistance to heat the windings during rotation. Once at temperature, a tiny stream of varnish is trickled onto the winding head. The varnish follows the wire into the entirety of the slot, eliminating chances for partial discharge in random windings. Once fully saturated, the current is increased in the windings, resulting in the varnish curing while on the machine. This process is faster and better than the traditional dip and bake process because it cures on the machine – making it ideal for emergency repairs. Check out more varnishing techniques in our article 4 Types of Motor Winding Insulation Methods.

How your water cooled injection molding machine motors are repaired is very important to the reliability and lifetime of your motor. If you need your water cooled motor repaired, make sure you consider which method is used for stripping the motor, how the motor is rewound and how the windings are varnished. If you have any questions on how our repair method for water cooled motors is different, feel free to call us today.

4 Types of Motor Winding Insulation Methods

March 5, 2019/by Lynn Dreisilker

After a motor is rewound, the windings must be further insulated with resin or varnish. This insulation protects the windings from contamination, shorting electrically, and also make the windings more mechanically rigid.

What are the different types of varnishing methods?

There are four types of varnishing methods that we will describe below: Dip and Bake Epoxy Varnishing, Trickle Varnishing, Vacuum Pressure Impregnation, and Ultra-Sealed Winding.

Dip and Bake Varnishing Technique:

Dip and Bake is a standard varnishing technique where the motor windings are dipped into a varnish tank and then set to cure in an oven. Typically, a new motor winding should be dipped twice (double dip and bake) to ensure the varnish fully covers the windings.

Many repair shops do not allow the windings to cool once they are cured in the oven after the first dip and before the motor is dipped a second time. Because the windings are still hot during the second dip, the varnish becomes more viscous and runs off the motor easily. This results in a less effective second dip of varnish.

Because we want to ensure adequate varnish coverage, Dreisilker’s quality standards denote that the windings must be cool before the second dip. Our varnish is Class N and Hermetic rated, meaning the varnished used can withstand higher temperatures and is fit for compressors (respectively).

Motor before being dipped in varnish.

Motor after being dipped in varnish.

Trickle Varnishing Technique:

Trickle Varnishing The winding is connected to a rotating table and electrical wires. Using electrical resistance, the winding gets heated while spinning. Once at temperature, a tiny stream of varnish is trickled onto the winding head. The varnish follows the wire into the entirety of the slot, eliminating chances for partial discharge in random windings. Once fully saturated, the current is increased in the windings, resulting in the varnish curing while on the machine. This process is faster and better than the traditional dip and bake process because it cures on the machine – making it ideal for emergency repairs.

Dreisilker’s Trickle Varnish Machine.

Trickle Varnished Winding.

Vacuum Pressure Impregnation Technique:

Vacuum Pressure Impregnation (VPI) utilizes a vacuum pressure tank filled with varnish to fully impregnate motor windings and insulation with resin or varnish. At Dreisilker, we preheat our windings, place the windings in our 10 ft. diameter tank, draw a vacuum, fill the tank until the resin or varnish covers all of the winding, then pressurize the tank. These cycles are all set to various times and capacitance is monitored to determine the resin or varnish fill is acceptable. This process is typically used on medium voltage motors and form coil systems because traditional varnishing methods will not fully saturate the motor coils and their insulation tapes with varnish. The VPI method is the most time consuming process.

Vacuum Pressure Impregnation

A 1,000 HP Armature being placed in our VPI tank.

Ultra Seal Winding Technique:

Ultra-Seal Winding is an alternative method of insulating a motor’s windings. Ultra-Sealed windings are completely impregnated and seals the coils with high molecular weight thermoset polymer resin. This allows for total protection against moisture, contaminants, and more efficient cooling. We recommend Ultra-Seal Windings for motors found in extreme environments, where contamination is likely. Want to learn more about Ultra-Seal Windings? Read our blog: How to Extend the Life of Your Servo and Spindle Motors in Extreme Environments

Ultra Seal Winding

Before and after a stator being Ultra Sealed.

Why is Varnishing Important?

Varnishing a motor winding protects the winding from contamination. Furthermore, it can protect the winding from shorting electrically and keeps the windings mechanically rigid. It’s important to understand which method would be best for your application. That is why our customer service representatives are trained in the different benefits that come with each method. If you have any questions regarding which varnishing method is best for you, reach out to us today: Electric Motor Repair Request