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Manufacturer s specifications should apply. For commutator machines, it should be verified that the brushholders align the brushes with the commutator bars and maintain equal circumferential spacing between brushes. Spring pressure should be measured and adjusted to a range recommended by the original equipment manufacturer or the brush manufacturer for the specific application and brush type.
For commutator machines, brush springs should provide the required brush pressure for successful commutation. Brushholders and jumpers should be high-potential tested to the machine frame at the test voltage specified for the corresponding winding circuit see Subsection 4. The face of the brush should be seated, or contoured, to make full contact with the commutator surface or slip rings.
The brush fit in the brushholder box should be inspected for side clearance see Table and for excessively worn brushes. Brushes worn beyond useful length should be replaced. Brushes in the same circuit of a machine should be of the same grade unless otherwise specified by the original equipment manufacturer.
Accepted methods of determining this position vary widely, and no single standard procedure applies. Note: In an assembled DC machine, each brush must contact at least two commutator bars at a time. Then, the brush short-circuits the armature coil connected to these bars.
Note: Some manufacturers intentionally 4. Capacitors should be replaced if damaged Starting Components and Switches Short circuit devices, centrifugal mechanisms, switches, and starting relays should be verified for electrical and mechanical operation at correct speed and voltage. These items should be replaced if damaged Terminal Boards Terminal boards should be replaced if damaged, with components of the same ampacity and temperature rating of the original components Space Heaters Space heaters should be tested for rated current or power and subjected to a high-potential test see Paragraph 4.
They should be replaced if damaged Temperature Sensors Bearing and winding sensors or protectors should be identical with or equivalent to the original devices in electrical and thermal characteristics. Table MG 1, Dimensions shown in millimeters are rounded off. Dimensions shown in millimeters are rounded off. Note: The permissible shaft runout tolerance has not been established where the shaft extension length exceeds the NEMA standard. However, runouts for shafts longer than standard are usually greater than those indicated above.
October Table Dimensions shown in inches are rounded off. October Section 2, Page 5 Table Galling materials, such as cast-iron, may require greater clearance. Vertical machines may require less clearance. Labyrinth seal clearance must always be greater than the bearing clearance. A general rule of thumb suggests labyrinth seal clearance should be mm greater than the sleeve bearing clearance.
Rabbet Diameter Table October Rabbet Diameter Table Thickness Max. To avoid confusion between dimensions in millimeters and in inches, brushes and brushholders may have markings as follows: metric dimensions ; inch dimensions. NOTE: Replacement of a brush made to inch dimensions with a brush made to millimeter dimensions or vice versa might cause problems because of an improper fit in the brushholder.
The above shaft interference fits and housing clearance fits are practical for most standard electric motor applications.
Where wider tolerances housing fits are permissible, use tolerance class h7 instead of h6. Some applications such as hollow shaft motors, spindle motors and vibrator motors require a different tolerance class than shown in the table. October Section 3 Rewinding 3. Any increase in losses should be investigated, and damaged laminations should be repaired or replaced Thermal Protectors or Sensors Thermostats, resistance temperature detectors RTDs , thermocouples and thermistors should be checked for electrical and physical defects.
Winding data should be reviewed for accuracy. Part temperature should be controlled to avoid degradation of the interlaminar insulation and distortion of any parts. The oven should use a water suppression system. Parts should be oriented and supported in the oven so as to avoid distortion of the parts. Core slots should be clean and free of sharp edges or particles. All components of the insulation system must be compatible with each other with respect to electrical, mechanical, and thermal characteristics.
The insulation system should withstand the high-potential tests described in Subsection 4. The temperature rating of the coil conductor insulation should be equal to or higher than that of the insulation system. If the conductor material is changed, it should be equal to or better than the original material in all aspects of performance and application.
The wire cross-sectional area should be at least equal to the original manufacturer s specifications Random-Wound Coils Coils should be wound and inserted in the core slots with a minimum of crossed conductors. Care should be taken not to damage the insulation or conductors. Coils should be wedged with full-length top sticks to hold them securely in the slots. Interphase insulation should be used where applicable Form-Wound Coils The fabricating of coil loops and the forming of these loops into the coil shape should be accomplished without damage to the conductor insulation.
Each layer of coil insulation should be uniformly and tightly applied to minimize stress points and air voids. Coils should be placed in the core slots without damaging the coil insulation. Coils should tightly fit slots. Coils should be wedged to hold them securely in the slots. Surge rings or similar supports should be secured to the coils and the coils laced to one another as necessary to minimize coil distortion and movement.
The insulation of the outer coil layer should be sufficient to withstand surges or inductive voltage spikes Rotating Coils Coils and pole pieces should be securely wedged and braced when installed. October Section 3, Page 2 ings should fit tightly in the core slots. End rings should be secured to the bars by welding or brazing, as appropriate for materials used. The winding should maintain the same electrical, thermal and mechanical characteristics as the original unless redesigned by agreement with, or at the instruction of, the customer.
On machines with surge rings coil supports , the rings should be suitably insulated, accurately fitted and laced to the coils to ensure adequate support for the winding.
Materials such as solder paste, fluxes, inhibitors and compounds, where employed, should be neutralized after using. These materials should be suitable for the intended use and of a type that will not adversely affect the conductors. Soldered joints should not be used in place of brazed or welded joints.
Connections and splices should be so constructed as to have resistance no greater than that of the conductors Insulating Connections Connections should be adequately insulated to withstand the temperature and voltage ratings of the machine and be mechanically adequate to withstand normal operation.
Connections and leads should be laced, tied, or otherwise securely fastened to prevent movement. It should be applied at the manufacturer s recommended tension and method of curing.
The banding should be of sufficient thickness and width to restrain the coils during normal operation. When wire banding is used, it should be applied to the winding over banding insulation.
The banding should match the original in location, material magnetic or non-magnetic , wire size and number of turns. The wire should be applied with sufficient tension to hold the coils in place without distorting them.
Caution: Replacing wire banding with resin-filled glass banding may change the magnetic circuit configuration, affecting commutation and thermal rating of the winding. The treatment should be compatible with the entire insulation system and suitable for the environment in which the machine is to operate.
October Section 4 Testing 4. Insulation resistance tests should be performed with acceptable results before the high-potential tests. Other tests, indicated below, may also be applied. All test results should be retained. Test The polarization index P. The recommended minimum value of polarization index for windings rated Class B and higher is 2. If the one minute insulation resistance is above megohms, the calculated polarization index P. In such cases, the P. For most DC armature and AC windings built after about form-wound coils.
For most machines with randomwound stator coils and formwound coils rated below 1 kv. Notes: 1 IR 1min is the recommended insulation resistance, in megohms, at 40 C of the entire machine winding. MG 1, Insulation resistance should be 1 megohm or greater. To avoid excessive stressing of the insulation, repeated application of the highpotential test voltage is not recommended.
Machines to be tested must be clean and dry. Inspection and insulation resistance tests with acceptable results should be performed before the high-potential tests.
Insulation resistance tests should be repeated at the completion of the highpotential tests. When a high-potential test is conducted on an assembled brushless exciter and synchronous machine field winding, the brushless circuit components diodes, thyristors, etc. High-potential tests should be successively applied between each winding or electric circuit under test and the frame or core of the machine.
All other windings or electric circuits not under test should be connected to the frame or core. Capacitors of capacitor-type motors must be left connected to the winding in the normal manner for machine operation running or starting. Electrical machines may be tested using AC or DC high-potential test equipment.
A DC instead of an AC voltage may be used for high-potential tests. In such cases, the DC test voltage should be 1. A failure under test can be less damaging to the winding if a DC voltage is used. AC high-potential testing should be performed by applying specified voltage at Hz continuously for one minute. DC high-potential testing should be performed by applying specified voltage for a duration of one minute after test voltage is reached.
The DC potential should be increased gradually to the desired test voltage in order to limit the charging current. Caution: After completion of a DC high-potential test, the winding must be grounded to the frame or core until the charge has decayed to zero.
To avoid excessive stressing of the insulation, repeated application of the high-potential test voltage is not recommended.
The tests should be applied once only at the specified voltage. Reconditioned Windings High-potential tests for reconditioned windings Tech Note No.
If you want to learn more about best practice machinery maintenance, or world class mechanical equipment maintenance and installation practices, follow the link to our Online Store and see the Training. Penrose, Ph. Maximum drying temperatures on windings should.
This principle. The amount of voltage produced depends on a variety of factors. Extra Questions - 2 1. A straight length of wire moves through a uniform magnetic field. The e. Box Aurora, IL Phone:. General 1. A general purpose motor for use in dry locations which are. Keen, May Welcome to Linear Controls Quarterly Training Introduction to Power Generation Objectives Supply attendees with basic knowledge of power generators and voltage regulators and provide the fundamentals of.
Consult your truck or trailer manufacturer s maintenance manual for proper. Motor Fundamentals Before we can examine the function of a drive, we must understand the basic operation of the motor. It is used to convert the electrical energy, supplied by the controller, to mechanical. Technical Data 7. Bearing Fits 7. Vibration Motor Application note Yangyi Chen April 4 th, 1 Table of Contents Pages Executive Summary 1 1.
Model number: Lenntech info lenntech. Bearing Failure: Causes and Cures bearing. Tight fits, brinelling and improper preloading can also bring about early fatigue failure. The solution. The first is to evaluate the existing system. These connectors are designed for use in pluggable. It will cover in a generic way most of the subjects which. Figure 6. Discuss the operation of selsyn motors. Discuss the operation of synchronous motors. Determine the direction of rotation.
All rights reserved. Specifications subject to change without notice. Last Update: December 8, A. Description of System Consultant s Handbook Page 1 of 6 1. Provide a diesel engine driven electric generating unit, factory assembled, tested and certified to operate at. The instrument is designed for use. Kapler, S. Campbell, M. Credland Iris Power Engineering Inc. Toronto, Canada Flux monitoring via permanently.
James M. Design Description AC Generators come in two basic types synchronous and non-synchronous. Synchronous generators lock in with the fundamental line frequency and rotate at a synchronous speed related to. On newer versions of Microsoft Word. Understanding Insulation Resistance Testing Why have an insulation testing program? A regular program of testing insulation resistance is strongly recommended to prevent electrical shocks, assure safety.
Special wiring is needed for battery cables. Lab 3-phase alternator. Objective: to obtain the no-load saturation curve of the alternator; to determine the voltage regulation characteristic of the alternator with resistive, capacitive, and inductive.
Trouble Shooting Pump Trouble Possible Cause Remedy Oil leaking in the area of water pump crankshaft Worn crankshaft seal, bad bearing, grooved shaft, or failure of retainer o-ring.
Excessive play on crankshaft. Scope This specification stipulates the minimum requirements for mechanically linked three-phase electronic sectionalizers, for use on outdoor medium voltage overhead lines of 15, 27, and 38 kv.
Gunite Disc Brake Rotors Maintenance Manual Gunite is the industry leader in the development of brake system components for heavy-duty truck applications including air disc brake rotors. Gunite was the. What is an Adjustable Frequency Drive? An adjustable frequency drive is a system for controlling the speed of an AC motor by controlling the frequency of the power supplied to the motor.
A basic adjustable. Don't know how? The EASA Technical Manual is without question the most valuable resource available for companies that sell, service, repair or rebuild AC and DC electrical apparatus, including motors, generators, transformers and electronic drives. Bishop, P. What makes it so valuable? The answer is simple. Need to convert AWG to metric wire size, or vice versa? Even high-potential AC and DC test voltages and scenarios for different types of machines are laid out in an easy-to-use graphic form.
The Technical Manual also contains dozens of practical articles, specifications, tips and procedures that cover the gambit of electrical apparatus service, repair, redesign and application, including electrical testing and mechanical repair, vibration analysis and balancing, and electronic variable-speed drives.
It also incorporates entire sections on DC machines and transformers.
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Whether you're seeking technical, management, sales or marketing help, EASA's extensive resource library is your main place to find articles, books, booklets, forms, webinar recordings, training films, products and more for your service center.
Look to EASA's technical support staff of 5 motor engineers and 1 pump, balancing and vibration specialist when you need help.
Access more than articles, books, booklets, forms, videos and webinar recordings to supplement your own reference libraries. The Resource Library is robust and searchable, helping you find the answers you need quickly and easily. With regular updates, you can rest assured that the content is up-to-date and relevant to your needs.
Looking for hard copies of these resources for your team or your customers? In response to various opinions about the feasibility of maintaining motor efficiency during repair, including replacement of the stator winding, the Electrical Apparatus Service Association EASA and the Association of Electrical and Mechanical Trades AEMT conducted two comprehensive rewind studies using third-party testing laboratories. This study was a follow up to a similar study conducted This valuable publication explains the findings:.
The study reaffirms the results of the study. Motors can be repaired without reducing efficiency. Published: January The original rewind study good practice guide has been editorially updated, with no substantive changes to any of the good practices. It contains repair tips, relevant motor terminology, and information about sources of losses in induction motors that affect efficiency.
Published: September Its purpose is to establish recommended practices in each step of the rotating electrical apparatus rewinding and rebuilding processes. The scope of this document describes record keeping, tests, analysis and general guidelines for the repair of induction, synchronous and direct current rotating electrical apparatus.
It is not intended to take the place of the customer's or the machine manufacturer's specific instructions or specifications or specific accepted and applicable industry standards or recommended practices.
Access industry-specific software to assist with your everyday operations. How To Wind Three-Phase Stators teaches how to wind in a richly detailed, step-by-step approach with 13 lessons containing narratives, animations and video clips and comprehension quizzes! At more than pages, leverage this resource for your service center technicians, either on your computer or on your bookshelf. Printed copies are available for sale.
Is safety a priority in your service center? Use the included documents to create or supplement your own safety program. Take your safety program to the next level and purchase related management and employee safety webinars focusing on specific areas of safety. More than just electric motors, EASA's resources, training and engineering support provide a wealth of tools for service center's that repair pumps. EASA's studies show that in many cases, motors can be repaired without a loss of efficiency.
Are you looking to buy a piece of equipment for your service center? Or do you have surplus equipment that you are interested in selling? Search the Resource Library Whether you're seeking technical, management, sales or marketing help, EASA's extensive resource library is your main place to find articles, books, booklets, forms, webinar recordings, training films, products and more for your service center.
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This valuable publication explains the findings: The study reaffirms the results of the study. Software for Your Service Center Access industry-specific software to assist with your everyday operations. Safety Module Program Is safety a priority in your service center? EASA offers a number of features to help you grow and manage your business successfully. Pump Repair Resources More than just electric motors, EASA's resources, training and engineering support provide a wealth of tools for service center's that repair pumps.
Maintaining Motor Efficiency EASA's studies show that in many cases, motors can be repaired without a loss of efficiency. Surplus Equipment Trading Post Are you looking to buy a piece of equipment for your service center?
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