This past year we had the pleasure of interviewing some very distinguished maintenance and reliability professionals working with our local industry. We talked about the mission of maintenance and the goals of manufacturing. We talked about the challenges of staffing, training, budgets, and even plant politics. The feedback we received helped us plan for investment,…

As mentioned in the previous post, High Resistance Connections are often the cause of premature motor failure. They develop slowly and over time begin affecting the applied voltage and current balance at the motor, resulting in numerous problems. These connections can be in the junction box, at the starter, or even at the internal connections of…

  It is a well accepted fact that accurate bearing fit is critical to bearing life and run life of the motor. With more than 40% of motor failures related to bearings, this best practice cannot be emphasized enough, especially since the variables of bearing fits are easily controlled in the motor shop. For more,…

“We were then satisfied that, with proper lubrication and better adjustments a little more power could be expected.” — Orville Wright Bearings can be found in most anything that rolls, from skateboards to rocket motors in billion dollar space shuttles. When expensive motors fail, the results can be catastrophic. Electric Motors also keep industry in…

Severe Duty Electric Motors: IEEE 841 Then and Now When NEMA established IEEE 841 in 1986, “rugged duty” motors could simply mean motor parts were cast iron or coatings and shafts were constructed to resist moisture and rust. Each motor manufacturer defined “severe duty” motors differently. This left users without a measurable standard to specify…

Surge testing helps identify a shorted motor conductor turn and as such is a powerful predictor of future motor failure due to turn-to-turn shorting. Failure of conductor insulation is the culprit here and is one of the first signs that a motor is going to electrically fail. The root cause is often insufficient insulation on…

Electrical motors might be called the “quarterback” of industrial activity. Intelligent motor protection relays can be considered the protective defensive line for monitoring, calculating and communicating potential overcurrent or overload conditions. Motor protection is used in residential (e.g., HVAC), commercial, and industrial facilities. Electrical professionals need to thoroughly understand the basic principles of motor protection…

  Polarization Index testing or PI testing is often misunderstood and misapplied. it’s a highly useful test to determine the health of motor insulation and in so doing, identify accumulations of contaminants and assess the physical health of the insulation. In short, polarization means to cause something to obtain polarity and this test causes molecules…

  A sound stator core is the foundation of a good motor winding. As we discussed in the previous post on Core Loss Testing, this test is essential to determining the viability of a stator core prior to motor rewind. In this video, we explore how to properly conduct core loss testing, the warning signs…

Installing motor bearings correctly is critical to long bearing and motor life with optimal performance. This post explores procedures for proper bearing preparation and installation in order to minimize the possibility of bearing and motor failure. Many bearings fail or will fail upon installation if proper shop procedures are not observed. Proper bearing installation To…

Proper assessment of motor bearing fits requires sound references and precision methods. Every motor repair requires an assessment of bearing fit, and fast-paced motor repair shops face the added challenge of repeated accuracy. This post will help you understand what your shop should be doing at a minimum to assess bearing fits. Why are motor…

  A sound motor stator core is the foundation of a good motor winding. As is the case with building construction, a good foundation is often taken for granted yet essential to longevity. This post will explore why it is so important to ensure that your rewinds start with a good core, and how you…

The polarization index test is one of the most misunderstood, and sometimes misapplied, of all electrical tests. This post will summarize some of the changes to the test over time and provide insight as to how it should, and should not be used. What is a Polarization Index test? The polarization index (PI) is used…

Electrical testing of motors can be very complicated, yet its importance is often under-estimated.  One of the most basic tests is the insulation resistance test, also referred to as the Megger test (due to the powerful Megger brand name). Though basic by nature Megger tests are very useful. However, if proper guidelines are not followed the results can be suspect.…

    Insulation Resistance testing is one of the most basic motor electrical test procedures that can be conducted in the field or in the shop. Yet it’s often overlooked as a source of valuable information, and it’s often misapplied due to some misunderstood fundamentals that must be observed when conducting an IR test. This…

Motor rotor balancing can be a confusing topic leading to sometimes heated conversation, especially in motor shops where cultures have evolved so differently over the years. All rotors must be balanced, whether new from the factory OEM or recently repaired. But the methods of balancing vary, as does the quality of the work. In this post…

This is the first in a series of motor repair best practices videos from EECO. These videos will help dispel some common misconceptions about motor repair, and highlight best practices related to industrial motor repair. To understand best practices in motor repair, you need to know how what to look for in your motor repair shop, and what…

According to industry sources, the U.S. spends over a trillion dollars a year on maintenance expense with more than 75% of those costs attributable to human error. While this is a source of concern for many maintenance managers, perhaps equally concerning is that one third of the expense is wasted expense. Good motor maintenance is predicated on…

Overcurrent or excess current is a situation where a larger than intended electric current exists. As we know, overcurrent or excess current is a situation where a larger than intended electric current exists. This leads to the excessive generation of heat and the risk of fire or damage to equipment and potential injury for workers.…

How innovative VFD enclosure design is helping to manage heat. VFD enclosure heat  is typically managed through tried and tested means such as forced ventilation, moving heat sinks to the exterior (through back panel) or other means such as air conditioning. Each of these are viable solutions, though environmental and operational considerations may impact suitability.…

Electrical motors are the heart of production… quick disconnects increase production. Motor lead quick disconnects allow for fast connecting and disconnecting of reliable motor lead connections, facilitating motor maintenance and repair or diagnostics and testing. Thomas & Betts Blackburn KUBE Motor Lead Compression Disconnects reduce labor time by 50% versus conventional disconnect methods, according to a T&B. This increases…

Getting control of inventory, coordination, code compliance and workplace safety. The complexity of short circuit protection has grown due to increased safety requirements. The major industry regulations and standards that that must be observed are OSHA, NFPA 70E®, CSA-Z462, IEEE Standard 1584, and NFPA 70®: National Electric Code®. Technology has also improved, providing for better…

Traditional fuses are designed to limit threats to people and property by protecting your electrical system from overheating, fire and arc flash. But increasing safety requirements have created an immediate need to reduce the potential for arc flash even further. OSHA, for example, uses the new requirements of NFPA 70E to judge whether an employer…

Making choices in a contactor or motor starter Its a question we hear often - "Is it a contactor or motor starter"? This question is understandable since contactors and starters both control electric motors and many people use the two terms interchangeably, which can lead to a little confusion. The mechanical elements of starters and contactors…

Electrical motors are vital to keeping your production moving, but they can also create unnecessary, and unexpected costs. Over time, those costs can creep up. Rising motor costs can be driven by a number of factors such as: 1. The application or environment exceeds motor capability, leading to premature failure 2. Undiagnosed operations issues, leading…

Proper electric motor balancing and precision machine work will extend the life of your motor, particularly the bearing life. So ask yourself this question, “How much could one extra year of run life on every motor repaired save you?” Answer: 14% if you are averaging 6 years, which could add up to thousands.   Electric motor…

Inspection is a critical portion of the motor repair job, and it defines the entire scope of work. You want answers to critical questions before you send a motor out for repair. You want to know: How thoroughly and accurately will the motor be inspected? What determines that the motor repair was successful and that…

EECO received its fourth Steelman burnoff oven on August 8th 2014 in Richmond, increasing investment in electric motor repair in Virginia. According to Frankie Johnson, Rewind Program Manager, “the winding team continues to implement tighter controls and acceptance testing requirements to increase the quality of rewinds”. Electric Motor Repair In Virginia – Our Program EECO provides…

A severe duty motor, in short, is an improvement over a standard totally enclosed fan cooled (TEFC) motor. They are tougher and better suited to an industrial environment. There is no standard specification on what a severe duty motor is, so designs vary. They could be viewed as a step between a full IEEE 841…

What is a high resistance connection? A lot of words come to mind when the term “high resistance connection” is used, though reliability is not one of them. Loose, poor, heat, imbalance, and failure are a few often associated with high resistance connection, and for good reason. They are often the root cause of motor…

The ODP vs TEFC debate has been extensively covered by others, but our repair shops find evidence of poor performing ODP applications on a monthly basis. Open drip proof motors are just that - open. It's like an open door from whatever is outside, to your bearings and windings on the inside. At one time…

Selecting NEMA motors- TEFC, severe duty, or IEEE 841 Making the right choice for low voltage motors can greatly affect total cost and reliability. There are so many types and manufacturers of motors that it can be difficult to make the right selection for any given application.  Our test teams and repair shops will occasionally…

Insulating Motor Connections For Reliability It’s the simple things that we seem to take for granted in an industry where so much experience is retiring away. How do you properly tape a motor lead connection? What type of tape do you use for a connection, and how many layers? We see lots of motor connections…

Motor connections that keep you running – Low Voltage Applications A proper motor connection is a fundamental and often overlooked component to a reliable motor circuit. Unfortunately, our test teams and repair shops continue to find problems with high resistance and grounded connections resulting from: Vibration Heat Moisture Contaminants Improper handing Compression in Jbox (too…