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  1. 5 Common Elevator Problems and Prevention Tactics


    From old operating systems to worn sheaves, there are a number of reasons why an elevator may be malfunctioning — and our team at Renown Electric is always available to help.

    Elevator Maintenance

    Many equipment failures can be prevented with proper inspection and preventative maintenance. Regular maintenance doesn’t just increase productivity by avoiding downtime — it’s also been shown to decrease energy consumption by 15%.

    Long wait times and frequent breakdowns are inconvenient and a sign of wear. Overheating, high energy use, and low power factor may not be obvious problems, but they incur hidden costs. Implementing simple elevator motor maintenance practices can help decrease expenses and downtime.

    Below, we examined some of the most common elevator problems and provided solutions to preventing elevator downtime:

    1. Problem: Worn Sheaves

    ✓ Solution: Sheave regrooving

    Sheave Regrooving

    Worn sheaves place extra wear on ropes, which in turn increases the level of wear on sheaves. This creates a cycle of destruction for both key components.

    Sheaves can be regrooved or replaced to prevent premature hoist rope failure, so be sure to check groove profiles to verify the fit between the ropes and the sheave.  Simple tools are available with magnetic standards and a straight edge to visually check if the grooves on the sheave a wearing evenly.

    2.  Problem: Power failure

    ✓ Solution: Infrared inspection

    Infrared Inspection

    Elevators demand a great deal of power from commercial building utility systems, so updates to the system’s voltage can affect motor operations or potentially even damage the elevator system. Elevators with any history of motor failures or operation issues should undergo a power quality survey.

    Infrared thermography measures drastic temperature changes and can identify possible trouble spots before they cause costly system failures.  Common faults such as over/under voltage can be seen easily with power quality surveys and fuses that are running hot can be quickly seen with infrared imaging before a motor loses a phase.

    3. Problem: Contamination

    ✓ Solution: Oil & lubrication analysis

    Oil Analysis

    When wear occurs, small metal particles are released in the oil and can interfere with the proper functioning of an elevator system. Similarly, improper lubrication or worn seals can cause contamination. Conduct an oil analysis to check the oil for various properties that may indicate contamination or wear inside of a motor.

    A high presence of bronze in the gear case oil can indicate premature wear on the crown gear of a geared elevator or high concentration of aluminum in your hydraulic tank may indicate pump housing wear in a hydraulic elevator.

    4. Problem: Noisy bearings or bearing malfunction

    ✓ Solution: Inductive absorbers

    Spherical Roller Bearing

    Bearing malfunction causes more than half of all motor failures. Noisy bearings are often attributed to vibrations within the motor. While variable frequency drives are helpful for decreasing your motor’s energy use, they introduce common mode current — a damaging byproduct that can increase these vibrations to dangerous levels through premature bearing wear caused by stray current.

    To address this challenge, consider using an inductive absorber, such as CoolBLUE, to absorb the currents and protect your system from potential breakdowns.  Additionally, ensure that all grounds are secured and connected to minimize troubles caused by electrical noise on the ground that may trip out systems or cause false counts in the system.

    5. Problem: Misaligned motor drive

    ✓ Solution: Motor alignment

    motor-alignmentWhen an electric motor is coupled to another piece of equipment, shaft alignment is critical. Without correct alignment, the motor bearings begin to wear. Shaft misalignment can be detected using advanced laser measuring equipment or by simply employing a straightedge and string.

    Alternatively, consider purchasing geared machines that employ flange mounted motors that do not require alignment if the machine is disassembled.

    5 Common Elevator Problems


    Other Solutions

    preventative-maintenance At Renown Electric, we offer

    preventative maintenance and on-site elevator repair services to customers across a broad range of industries.To learn how to avoid the causes of elevator malfunction altogether, check out our

    eBook: Preventative vs. Predictive Maintenance.

  • Preparing for Your Scheduled Shutdown? 7 Things to Check

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    Facility equipment — especially industrial motors — naturally wear down throughout operation, sometimes to the point of failure.

    In order to avoid costly unplanned downtime, plant managers should administer scheduled shutdowns at least once a year. Annual motor maintenance not only lengthens equipment life — it also decreases energy consumption.

    Vibration Analysis

    These planned shutdowns allow for comprehensive testing and tune-ups for all motors and machinery, identifying potential issues and replacing parts as needed.

    At Renown Electric, our experts are heavily involved in planned shutdowns, many of which occur during the summer months. We regularly visit plants during their planned shutdowns as part of scheduled preventative maintenance (PM) programs to run an array of sophisticated tests that reduce or eliminate motor failures.

    Below are some of the most common issues associated with equipment failure that should be on your maintenance checklist.

    1. Vibration Analysis

    Vibration analysis is the most common technology used for testing the health of a motor. Advanced equipment analyzes the vibration signals (or signatures) that generate from rotating equipment.

    Experts examine the patterns of these signals and compare them to baseline data taken at initial machine start-up. Excessive vibration generally indicates a problem exists, with some of the most common sources being bearing failure, imbalance, and misalignment, among others.

    2. Bearing Malfunction

    More than half of all motor failures originate in problems with bearings. A worn, over-lubricated, or under-lubricated bearing will vibrate excessively — especially before an equipment failure.

    After detecting a potential bearing issue, maintenance professionals can determine and treat the exact source of the problem. Solutions include rotating motors to avoid denting bearings, ensuring proper installment and fit, and providing proper lubrication and effective seals.

    3. Unbalanced or Overload Voltage

    Renown Infrared Thermography Analysis

    Handheld infrared devices help detect hotter-than-average motor temperatures and capture two-dimensional images. Increased temperatures often signify unbalanced or overloaded voltages. Thermal images and temperatures taken during normal operating conditions should be compared to readings taken while testing.

    When necessary, a researcher can identify and correct the potential causes of unbalanced or overloaded voltages. Some of these include hotspots in winding connects, short circuits in a coil, or possibly a broken or cracked motor shaft or rotor.

    4. Motor Drive Alignment

    Misalignment occurs when motor shafts and their respective pumps, generators, or other plant systems are not properly aligned. This condition creates excessive and rapid wear on bearings and harsh effects on belt drives. Misaligned motors also increase friction on a shaft, making it difficult to turn and wasting energy.

    The overall impact of misalignment ranges from downtime and lost production to fire safety hazards. Advanced laser measuring equipment can easily detect misalignment and should be regularly checked to ensure smooth motor operation.

    5. Motor Winding Analysis

    Problems in electrical equipment often cause unscheduled shutdowns and sometimes catastrophic failures. Electrical motor winding analysis (MWA) is a non-destructive testing technique that enables early detection of difficulties in electrical equipment.

    MWA covers windings in motors, transformers, generators — virtually any electrical component. It can be applied to AC, DC, and synchronous motors while the equipment is out of operation, ensuring the strength of winding insulation and indicating where repairs are needed.

    6. Motor Balancing

    Gearless sheave regrooved on dynamic balancer

    Out-of-balance motors are generally easy to detect: upon start-up, motors with balancing issues cause excessive vibration and noise that tends to increase with the speed of the motor’s operation.

    If not dealt with quickly, off-balance motors can precipitate bearing wear, structural damage, and possible equipment failure.

    While some plant operators send motors to manufacturers to correct this problem, on-site dynamic balancing has many advantages. It is faster, less expensive, and allows for compensation in its surrounding components during and after repairs.

    7. Contamination

    Examining the content and contamination of oil provides excellent information about the state of the motor itself. The wear from a motor’s moving parts emits particles into the oil. Measuring the oil’s contamination, oxidation, and viscosity on a regular basis reveals the rate of wear the motor is undergoing and can highlight issues like current running through the bearings.

    Oil sampling should be part of every company’s testing during scheduled maintenance, allowing for the health of the machine to be effectively monitored at minimal costs.

    Physical contamination can also be a major problem.  Motors that run in environments where airborne contaminants fall on motors will create an unwanted insulation layer.  This layer of waste does not allow the motor to vent heat properly leading to motors overheating and failing prematurely.  Consider dry-ice cleaning or other methods to eliminate the layer of built up materials on motors to allow for effective heat transfer and longer operating life.

    Ongoing Preventative Maintenance Tips

    Preventative Maintenance

    In addition to scheduled shutdowns, the following represent a few preventative maintenance steps that can help maximize the safety and efficiency of your equipment’s operation.

    – Lubricate equipment regularly
    – Inspect bearings at a predetermined schedule
    – For heavy duty motors, check bearings regularly
    – Check belt tension
    – Inspect DC motors’ brushes and commutators
    – Check contacts for pitting and indications of overheating
    – Keep accurate records

    Contact Us

    Performing an annual shutdown for diagnostics and preventative maintenance can have a profound impact on the safe and efficient operation of your plant. At Renown Electric, we have the experience and expertise to ensure your maintenance is completed comprehensively and at the highest levels of accuracy. We also have spare motor parts for any replacements you require.

    For further questions or to schedule one of our experts for your shutdown, contact us today.

  • What’s that Noise My Motor Bearing is Making?

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    In the course of our work, our team at Renown Electric Motors & Repair Inc. comes across a lot of motor drive and motor bearing issues.

    Noise coming from the motor drive or bearing is a particularly common complaint. Working with our partner NTN Corporation, a Japanese bearing manufacturer with global reach, we compiled a few common causes of noise and vibrations in bearings and drives — and how to fix them.

    What noise is my motor bearing making?

    Cylindrical Roller Bearing

    A motor bearing may make any number of noises, not all of which are indicative of a serious issue. Tinkling or rustling sounds, for example, are generally caused by dust or dirt and can be resolved with a decent cleaning. Others, however, can be more problematic.

    Buzz or Roar

    If your bearing is making a vibratory sound ranging from a light buzz to a considerable roar that increases in volume and pitch as speed changes, this is problematic.

    Spherical Roller Bearing

    This issue can be caused by any one of a number of factors, including resonation, a poorly shaped shaft, deformed bearing, brinelling, or vibrating parts. Note that in very large bearings, a minor buzzing is normal.

    Screech or Howl

    A screeching or howling sound, particularly on cylindrical roller bearings, that changes with speed is an indication of radial clearance that is too large.
    (Note that if the sound is metallic and fades temporarily after being greased, the lubrication you are using is of a poor quality.)


    A crunching sound, especially one that can be felt when the bearing is moved by hand, could be caused by a deformed bearing or bad dust contamination. More seriously, it could mean that balls, rollers, or raceway surfaces are being scored.


    A chatter that is audible not only at high speeds but at low ones as well can mean that the rollers on a full-roller bearing are bumping into each other.

    Find more causes of noise and vibration in NTN’s Motor Bearing Care & Maintenance Guide.


    Why is my motor vibrating?Motor Bearing Maintenance Guide

    What do each of these sounds have in common? They can be traced back to vibrations in the motor. The degree of the damage caused by these sounds’ sources depends on both the amplitude and frequency of the vibrations causing them.

    Slight motor vibration is normal. The presence of a variable frequency drive (VFD), while helpful for decreasing energy use, introduces electrical noise in the form of Common Mode Current. Common Mode Current can increase vibrations to dangerous levels that can cause audible noise issues and, more worryingly, badly damage your motor bearings.

    The Ultimate Solution

    CoolBLUE inductive absorbers, also called common mode chokes, are inductors that have been specially designed to reduce common mode current — they absorb the electrical noise, thus “choking” the current.

    Proper installation of CoolBLUE inductive absorbers and NaLA differential mode line absorbers, both manufactured by Renown partner MH&W International, can decrease VFD-caused Common Mode Current drastically, as much as 70% or more. By reducing this noise and the vibration it causes, you will maximize the longevity and reliability of your equipment while minimizing maintenance cost and unscheduled downtime.

    Learn more about Renown’s CoolBLUE Inductive Absorbers or see how they work in our motor bearing current case study.

  • How It Works: CoolBLUE Common Mode Chokes for VFDs

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    Learn how inductive absorbers reduce damage to motor bearings and extend equipment life

    How It Works

    This post continues Renown’s monthly series called “How It Works,” featuring articles that detail the inner workings of motor maintenance services and processes.

    Electric motors are increasingly being equipped with variable frequency drive (VFD) systems for the energy efficiency the combination creates. This efficiency saves money both directly by reducing energy costs, and indirectly by increasing output.

    Yet as most good things do, VFD systems have a small drawback: they create a considerable amount of unwanted high frequency currents to the motors in the form of motor bearing currents. Renown Electric recently partnered with MH&W International to offer a solution to this problem — CoolBLUE Inductive Absorbers.

    Effects of VFD Vibration

    The side-effect that is caused by VFD systems are actually generated by the IGBT’s switching frequency in their common-mode output. Created by the VFD itself, the unwanted current travels to a motor and its bearings via the motor leads that attach the VFD system to the motor.

    Cool Blue Chokes

    When the  common mode current reaches the motor, they travel through both the motor and its bearings in the form of  motor bearing currents. These  currents can be measured using a special instrument called a Rogowski Coil and an oscilloscope.  These damaging currents cause a great deal of electrical noise and, more importantly, a laundry list of mechanical issues that collectively reduce the efficacy and lifespan of the motor:

    — Bearing fluting

    — Bearing frosting

    — Lubrication breakdown

    — Pitting

    — Electrical discharge machining (EDM)

    What are CoolBLUE Inductive Absorbers?

    Inductive absorbers are more commonly known as common mode chokes. They are self-contained electrical inductors used to block and absorb — in other words, to choke — electromagnetic interference (EMI) and radio frequency interference (RFI).

    Both common mode currents, EMI and RFI are the two causes of the EDM effect in bearings created by VFD systems. They do this without blocking differential currents, the currents passing through the power cables that are required to power and control the motor.

    Unlike dv/dt filters, designed to limit voltage spikes in long lead length applications, CoolBLUE cores are designed to specifically choke off the unwanted high frequency currents that are created by the switching of IGBT’s and SCR’s.  This frequency is in the order of 500 kHz to several MHz whereas your control frequency is in the range of much lower kHz.

    CoolBLUE Inductive Absorbers do not block all of the EMI and RFI currents, but they do restrict the majority of them — between 65% and 80%, which is more than enough to prevent them from damaging your motor. When installed properly, CoolBLUE Inductive absorbers will reduce common mode currents.

    How to Use CoolBLUE

    CoolBLUE Inductive Absorbers are extremely simple to install. Disconnect the power cords between the VFD and the motor, insert the phase cords thru the applicable cores — always exclude the grounding wire, leaving it out of the CoolBLUE mode chokes — and reconnect the power cords. The photos below show a few example CoolBLUE installations.

    Cool Blue Installation

    Some installation considerations to keep in mind:

    — CoolBLUE units can be installed on AC, DC, Permanent Magnet motors and Servo Applications

    — Keep the chokes as close to the VFD as possible

    — Install NaLA Noise Line Absorbers for added protection

    — Loop motor leads twice through the CoolBLUE chokes for smaller applications between 1/4hp and 10hp

    CoolBLUE from Renown

    Renown Electric is proud to offer the full line of CoolBLUE Inductive Absorbers to help you to extend the life of your motor today.

    To learn more about CoolBLUE chokes,  download our free Design and Installation Guides today.

  • How It Works: Winding Analysis

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    How Winding Analysis Keeps Motors Running within a Predictive Maintenance Program

    How It Works

    This post is the third in a monthly series of “How It Works” articles that detail the inner workings of motor maintenance services and processes.

    Winding Analysis

    The failure of a large motor can be deeply disruptive to the rest of a facility’s operations. Our monthly series in understanding how your motor works — and the preventative and predictive maintenance services and processes that can make it work better — is why we’re here.

    In our third post of this series, we’ll be investigating winding analysis. Along with dynamic balancing, laser alignment, infrared thermography, oil analysis and vibration analysis, winding analysis is a basic maintenance operation that can enhance motor life and decrease energy consumption.

    Evaluating Motor Lifespan

    Preventative maintenance on an electric motor relies on two types of analysis:

    By assessing when and how a motor can be affected, it’s easier to detect and resolve potential motor issues before they actively occur, allowing maintenance to be carried out effectively — and preemptively — during scheduled shutdowns. This avoids costly failures, unscheduled maintenance, and premature issues in equipment.

    Motor Winding Analysis Tests and Tools

    A form of non-destructive testing, motor winding analysis can be applied not only to motors, but to transformer and generator windings as well. Along with Motor Current Analysis, this testing is used specifically to classify electric winding insulation, but the information it provides is significantly more sophisticated.

    Example of a Failed Winding Analysis Report:

    Failed Winding Analysis

    Example of a Successful Winding Analysis Report

    Successful Winding Analysis

    Many problems that indicate premature failure of motor components can be revealed through the information collected through Motor Winding Analysis. Helping to detect and eliminate winding issues and their subsequent related problems, as well as monitoring the dielectric strength of winding insulation, is critical in preventing overall failure and determining the urgency of repair needs.

    Two types of testing constitute a full motor winding analysis. They are:

    These tests can be conducted with the help of an Advanced Winding Analyzer (AWA-IV) and a Baker D65R, depending upon motor type.

    Winding analysis can also be utilized as a powerful troubleshooting tool. Many facilities utilize a hand held megger to test the insulation strength. This is an effective method for detecting ground faults. However, internal shorts within the windings may not appear as a ground fault. As a result these faults may be missed during troubleshooting costing valuable down time. A winding analysis test will detect even slight resistance unbalance between phases and the surge test will quickly detect internal shorts within the windings.


    Surge TestUsed to test a variety of inter-winding faults that DC tests will not normally detect.

    Surge Comparison TestA comparison of two individual Surge Test wave patterns from separate windings to see if they differ. Two methods of comparing wave patterns are Error Ratio (E.A.R.), or Zero Crossing Tolerance. When the wave patterns are the same, there is no short in either winding.  When the wave patterns differ, one of the windings contains a short.

    Surge Waveform (Surge Data): The resulting data from a surge test. It can be viewed graphically on the View Waveforms screen.

    Megohm TestA low-voltage test used to measure the insulation resistance of a winding in megaohms. In Automatic Test Mode, for motors rated less than 600 volts, the test voltage will be 500 volts.

    For motors rated more than 600 volts, the test voltage will be one-third that of the default test voltage table.

    Polarization Index: A ratio between measured insulation resistance values taken at one minute and ten minutes. It is obtained from data that is collected every two seconds. Note: The PI test is useful for testing complex insulation systems, such as large motors and generators, where repeatable measurements are difficult to obtain.

    “Hipot” Trip Fault DetectionBuilt-in circuitry that will stop any test when it detects Hipot current levels that are higher than a predetermined safety limit. After a Hipot Trip, a message will appear on the screen and “Trip” will be entered into the motor data form. The test will be considered “failed.” It will set to 600u amps when the Analyzer Hipot test is set to 100ua/div and 60 u amps when using the 10 or 1 u amps setting.

    “Hipot” is short for high potential (high voltage). A hipot test checks for “good isolation.” Hipot tests are conducted to ensure no current will flow from one point to another point. In some ways a hipot test is the opposite of a continuity test.

    Continuity Test: Ensures current flows easily from one point to another point.

    Hipot Test: Ensure current will not flow from one point to another point.

    The team at Renown Electric provides these services both in the shop and on the road, along with a host of additional maintenance services to keep your systems running smoothly. To view a sample of a real winding analysis report, access the report from our resource library.

  • Renown Electric Now Offering CoolBLUE Inductive Absorbers

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    The inductive absorbers help extend motor bearing life and reduce maintenance costs.

    Inductive Absorbers

    Renown Electric Motors & Repair now offers CoolBLUE Inductive Absorbers for motor bearings thanks to its recent partnership with MH&W International Corp. of Mahwah, NJ.

    The absorbers serve electric motors equipped with variable frequency drive (VFD) systems, which can create damaging motor bearing currents that often lead to lubrication damage and electrical discharge machining.

    If these issues are not corrected, full failure of the motor bearing and damage to the motor itself can occur.

    Cool Blue Absorbers

    CoolBLUE inductive absorbers, or common mode chokes, are easily installed around the power cables that run from a VFD to a motor.  CoolBLUE inductive absorbers “choke” the unwanted high frequency currents created by drives, filtering them out of the system before they cause damage. When installed, CoolBLUE inductive absorbers reduce noise, over-voltage peaks, circulating and motor bearing currents, and asymmetrical electromagnetic interference (EMI) currents, all created by VFDs.

    These absorbers help electric motors run more reliably and lengthen the motor’s lifespan. By controlling the damaging currents created by VFD systems, they also help to reduce downtime and costly maintenance.

    In addition to the new CoolBLUE product line, Renown Electric also offer a number of free design and installation guides for CoolBLUE products. The guides outline CoolBLUE features, types of equipment and applications for which the inductors are designed, and easy-to-follow installation instructions.

  • How It Works: Dynamic Balancing

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    How It Works


    This post is the second in a monthly series of “How It Works” articles that detail the inner workings of motor maintenance services and processes.

    Large motors are sophisticated machines, and their failure can be deeply disruptive to the rest of a facility’s operations. Understanding how your motor works — and the preventative and predictive maintenance that can make it work better — can both enhance the life of a motor and decrease its energy consumption.

    Rotating Machines and Vibration

    Anyone who works with rotating equipment knows that proper alignment and balance are key to its function. Improper dynamic balance — the most frequent type of balance problem — can cause excessive vibration, which in turn can damage the machine. Balance problems can produce:

    On-site Balancing

    Large motors can’t simply be sent back to a manufacturer for fine-tuning, however; the transportation costs and delivery times are too much of an investment, and the potential risk of damaging rotor assemblies during travel is an unnecessary stressor.

    In response to this problem, on-site balancing technicians have developed tools and services to bring routine balancing maintenance, and thus optimal machine life, to the motor’s real-time operating environment. By evaluating the motor in its native setup, technicians can compensate for assembly tolerances in gears, couplings and other components, and not to mention, save time for the facility’s operations team.

    Dynamic Balancing Tools and Processes

    Rotor imbalance is usually resolved at a machine’s startup. An exception to the rule, however, presents itself in variable speed machines, which will show increasing vibration with increasing speed.

    If sudden vibration occurs on your motor, first check for:

    An on-site technician can further assist your initial assessment by:

    The team at Renown Electric provides a host of maintenance services, including on-site dynamic balancing. To learn more about it or to see how they can help, ask about our field services.

  • How It Works – Carbon Brush Operation


    How It Works – Carbon Brush Operation

    This post is the first in a monthly series of “How It Works” articles that detail the inner workings of motor maintenance services and processes.

    Though they are frequently overlooked, carbon brushes are one of the most critical elements of a motor.

    A carbon brush, also known as a motor brush, is the small part of the motor that conducts electrical current between the stationary wires (stator) and the rotating wires (rotor) of a motor or generator. The brush is typically made up of one or more carbon blocks and can come with one or more shunts or terminals.

    A motor generally contains more than one carbon brush to conduct electrical current. The brushes are categorized into five brush-grade families, each of which is suited for different kinds of motors and applications.

    A carbon brush has three operating parameters: mechanical, electrical, and physical/chemical.


    A slip ring or commutator is attached to the rotating shaft. A spring is used to push the brush into the slip ring or commutator to maintain contact. The surface of the slip ring or commutator should not be too smooth/glossy or too rough in order to ensure good brush contact and performance.


    Electrical Carbon Brush Operator

    Electrical current is transmitted from the rotating shaft via contact with the carbon brush. Very small areas of the brush, called contact spots, contact the surface of the slip ring or commutator. The contact spots should be evenly distributed on the surface of the brush to maintain brush balance and avoid damage to the commutator/slip ring surface.

    Carbon brushes with high resistivity work best, because this helps prevents arcing at the interface between the brush and commutator/slip ring.  It is also important to maintain a proper power density for DC motors to operate at peak performance which often requires removing brushes.  Calculations for power density should be performed and brush density optimized if your application changes. Brushes should not be assumed to be missing if you find a DC motor operating with brushes removed.


    This operating parameter refers to the operating environment of the carbon brush, rather than to the brush itself, which can have a strong effect on carbon brush performance.

    For example, a certain level of air humidity is needed for the commutator/slip ring film to form properly. Thus, if air is too dry, such as in desert, arctic, or aerospace conditions, special brush treatments are recommended. Treatments are also available for brushes exposed to corrosive vapors and gases (which can occur, for example, in the presence of silicone or other adhesives). Finally, oils, hydrocarbons, and dust can deteriorate a carbon brush and should be avoided.

    Carbon Brush

    How Are Carbon Brushes Maintained?

    There are several ways to check for issues and to be sure your carbon brush — and your motor — are working properly.

    One of the first things to look at is carbon brush stability. Check the clearance between brush holders and the brush to ensure it is stable and slides properly. It’s also important to check the distance between the brush holder and commutator slip ring to ensure the brush holder is adjusted correctly and at the proper angle.

    It is important to also check for signs of commutator wear and for the presence of copper dust. Dust leads to high brush wear, machine pollution, grooving of commutators/slip rings and brush side gulling. The best way to prevent this is with regular motor cleaning to ensure air filters provide clean air to the motor.

    At Renown Electric, we know motors. In fact, for over 30 years we have provided our customers with the highest quality electric motors and electric motor repair services.

    For a complete checklist on carbon brush maintenance, as well as information about installing carbon brushes, download our eBook Technical Guide: Carbon Brushes for Motors and Generators.”

     Carbon Brush Operation




  • Why Would I Keep My Old Motor?

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    Internal Motor

    The current push in today’s world is to upgrade everything to a more energy-efficient state. This is true for cars, appliances, and electric motors.

    If you are deciding whether to keep your old motor or to replace it with a new one, please consider the following:

    Production/Operation Downtime

    Motor replacement requires an associated amount of pre-planning or downtime in operation or production that could be avoided by simply keeping the working motor you already have. Small repairs often take less time than ordering and installing a new motor, which would equal more downtime.

    By pre-planning for the replacement, the best solution — a combination of motor efficiency, cost and performance — can be determined and ordered to avoid rush charges or costly mistakes made when under the pressure of a machine being down.

    Starting Torque

    The starting torque for old motors is generally much higher than starting torque for new motors. This means that replacing your old motor would likely also require installing a new drive into your current machine or equipment, which may not be the most convenient option.

    Often an updated control scheme, as simple as a soft-start, will help reduce the cost of electricity consumed on start-up while maintaining the torque required for the machine.  If a new high efficiency motor is required, careful consideration to starting torque or full load torque may determine that the motor and drive be sized as much as 150% larger in order to achieve the same results as old wound rotor motors.


    Although replacing your old motor with a newer motor—particularly one with a more efficient motor—may save your company money in operational costs, it may still not be the most cost-effective solution for you. Often, the cost of maintenance and preventative care for your current motor is much less than the cost of replacing it with a new one.

    Some operating costs can be saved by adding soft starts or VFD’s which have incentives from the power companies that may be as high as 100% of the cost of the VFD.  Often simple things like not stopping and restarting large motors between 11am and 5pm will reduce your energy costs substantially.

    In addition, if the motor is small or only used sporadically, the energy savings of a new motor may not be significant enough to warrant the upgrade. Simple calculations can be made to determine if a motor upgrade would really be the best option.

    At Renown Electric, we offer a selection of the highest quality electric motors to provide you with the motor you need. We are specialists in motor maintenance and replacement.  Please consult one of Renown’s motor specialists to help you determine the best course of action to optimize both cost and performance.

    If you are interested in keeping your old motor and want to make sure that it is well maintained, download our eBook “Preventative vs. Predictive Motor Maintenance.


  • Preventative vs. Predictive Motor Maintenance: Which Is Right for You?

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    Downtime from a faulty or burned out electric motor can create unnecessary work.

    No matter the type of equipment the motor powers, when electric motors fail productivity plummets and frustration grows. Non-efficient motors consume a great deal of daily energy demands, including:

    Preventative vs. Predictive Motor Maintenance

    While some electric motors fail with no warning, the majority of failures come about due to a lack of a proper maintenance program. Unfortunately, many companies still stick by a “run to failure” maintenance strategy. That is exactly what it sounds like: run motors into the ground and just replace them.

    It is not the greatest idea in the world, because it kills productivity and can create expensive repairs. When it comes to electric motors, most experts agree that you have two real options: preventative or predictive motor maintenance.

    Preventative Motor Maintenance (PM) is either time-based or schedule-based. This forces maintenance checks regardless of the actual condition of the equipment. This type of maintenance is an effective way to guarantee the dependable and long-life operation of electric motors. The major downside has to be the set costs, which can eat into your bottom line. You will end up spending the same amount every year whether the equipment needs the maintenance or not.

    Predictive or condition based Motor Maintenance (PdM) is where machines are measured with objective machine monitored trending methods. One immediate benefit of PdM is that you end up avoiding unnecessary repair costs and downtime. These non-intrusive testing techniques rely on proven scientific methodologies to predict the condition and lifespan of your electric motors.

    Some of these high-tech methods include:

    You can combine all of these methods into one PdM that will instantly increase your ability to avoid major electric engine breakdowns and incidences. It is a perfect example of how common sense and high-tech equipment come together to save you tons of time and money.

    If you want to learn more about the ins and outs, of both preventative and predictive motor maintenance, we suggest that you download Renown Electric’s free eBook, Preventative vs. Predictive Motor Maintenancefrom our website today.

    Of course, if you want to talk directly with an electric motor maintenance expert, feel free to email us or call us toll-free at 877-742-3665.

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