Motors must always be accurately aligned, and this applies especially where they are. Some standard lincoln electric motors are also capable of pws, yds or both as. Take input voltage to the motor using the volt ohmmeter. Troubleshooting electric motors presents learners with a practical approach to troubleshooting motors and equipment in electrical systems. This textworkbook provides a framework for acquiring the technical knowledge and applied skills needed by maintenance electricians and those in related electrical occupations. Tips for troubleshooting electric motors understanding the nuances of various motor types is essential when servicing or installing such units b y d e n n i s b u s h a fter more than 100 years of use, with an ever increasing installed base, there are probably few aspects of an electric motor s. Electric motor maintenance and troubleshooting, 2nd. Unlike an ohmmeter, a megger can measure highvoltage resistance values, which are generally the kinds of values you will encounter with threephase motors. Motors must always be accurately aligned, and this applies especially where they are directly coupled. Electric motors have energized circuits, exposed rotating parts and hot surfaces that may cause serious. Electric motor maintenance and troubleshooting, 2nd edition. Check the reason for the unbalanced threephase power supply, if it is caused by the power voltage or the motor itself.
By observing a few essential rules, you will ensure problemfree operation for many years. Essential for anyone who needs to buy, install, troubleshoot, maintain, or repair small to industrialsize electric motors, this practical guide contains new information on three phase motors along with coverage of the. It is true that single phase motors are less efficient substitute for 3phase motors but 3phase power is normally. Three phase motors are normally used in commercialtype operations. We thank you for making this choice, and would ask you to read the contents of this manual. Use features like bookmarks, note taking and highlighting while reading electric motor maintenance and troubleshooting. Dec 12, 2012 i will discuss further about troubleshooting guide for electric motors in my next part 2 of troubleshooting electric motors. Sterling 3 phase ac induction motors selection information buyer shall be solely responsible for determining the adequacy of the product for any and all uses to which buyer shall apply the product. First, the drive input is the ac power entering the drive from the mains second, the drive and its output, where the ac to dc. To measure the resistance in a threephase motor, you will need a megohmmeter, otherwise known as a megger. Unit 16 electric motors objectives after studying this unit, the student will be able to state the purpose of an electric motor. Check the voltage in all three phases at the motor.
Disconnect power to the motor before performing service or maintenance. Installation and maintenance threephase induction motors. Post a question or comment about how to troubleshoot electric motors such as air conditioning compressor motors, heating equipment burner or fan motors, swimming pool. Electric motor maintenance and troubleshooting, 2nd edition kindle edition by hand, augie. Sterling 3phase ac induction motors selection information buyer shall be solely responsible for determining the adequacy of the product for any and all uses to which buyer shall apply the product. A fully uptodate, handson guide to electric motors. First, the drive input is the ac power entering the drive from the mains. Threephase dualvoltage motor insulation resistance testing. Every good electrician knows the lead numbering sequence of three phase motors, or he has diagrams available for ready reference. The modern electric motor installation the individual motor drive has practically replaced all other types. Some standard lincoln electric motors are also capable of pws, yds or both as indicated in the following. It should be less than the full load rating stamped on the nameplate only true for three phase motors. Post a question or comment about how to troubleshoot electric motors such as air conditioning compressor motors, heating equipment burner or fan motors, swimming pool motors, water well pump motors. Power supply test for three phase motors, the expected voltage for a 230400v system is 230v phase to neutral and.
Electric motor maintenance and troubleshooting, second edition explains in detail how all types of ac and dc motors work. Industries of today use three phase motors widely in highpower applications. Singlephase motors are found in a long and diverse list of devices like washing machines, mechanical clocks and generators. How to test a 3 phase motor is discussed in this article. It is essential that electric motors are installed by experienced, qualified and. Many standard motor starters contain overload relays which will not respond to this situation, however, threephase phase protection relays are available to protect motors. Three phase induction motors are one of the most popular electric motors commonly found in processing plants or any manufacturing concern. Download it once and read it on your kindle device, pc, phones or tablets. Handson and lecture the participant is able to learnbydoing in the course.
Single phase motors are found in a long and diverse list of devices like washing machines, mechanical clocks and generators. I am leaving off several important parts of the story. Troubleshooting an electric motor that is suspected to have an electrical. How to test a threephase motor with a megger hunker.
Oct 27, 2008 in troubleshooting a motor you may need to verify that the motor lead numbers are correct, and that there have been no electrical faults that create short circuits between the different phases. The following is some common faults and troubleshooting method of threephase induction motors for your reference. This textworkbook provides a framework for acquiring the technical knowledge and applied skills needed by maintenance electricians and those in. The solution will prevent damage from freezing in temperatures to 40 f 40 c. Check manual release to be sure it operates properly. Motor troubleshooting includes a motor connection box to practice handson skills such as troubleshooting faults in a dc motor and ac single phase and three phase motors, evaluating dc electric motor commutator and brush health, and using a multimeter to test an ac motor startrun capacitor. The fill solution consists of a mixture of deionized water and propylene glycol a nontoxic antifreeze. This textworkbook provides a framework for acquiring the technical knowledge and applied skills needed by maintenance electricians and those in related. Threephase motor troubleshooting electric motor fuse electrical.
Threephase motor troubleshooting free download as pdf file. If the motor doesnt rotate in twophase operation, find the reason for phase loss and eliminate it. Tips for troubleshooting electric motors understanding the nuances of various motor types is essential when servicing or installing such units b y d e n n i s b u s h a fter more than 100 years of use, with an ever increasing installed base, there are probably few aspects of an electric motor s usage and failure modes. How to test three phase ac motors learning electrical. All motors are suitable for full voltage or acrosstheline start. Three phase induction motors tecowestinghouse motor company 5100 north ih35 round rock, tx. That way you can rule out the starter and all the conductors to the motor.
Here are the different test points in a typical threephase motor drive system figure 1. Threephase motors wyes and deltas 3, 6, 9, and 12 leads dual voltage connections. These motors have fewer parts and are more sturdily built than their single phase counterparts. By observing a few essential rules, you will ensure problemfree operation for. Always keep hands and clothing away from moving parts. Motors are susceptible to the gradual failure of their insulation resistance. These motors run conveyor belts, pumps, fans, and many other applications.
Motor controls troubleshooting of electric motors relay. In troubleshooting a motor you may need to verify that the motor lead numbers are correct, and that there have been no electrical faults that create short circuits between the different phases. To measure the resistance in a three phase motor, you will need a megohmmeter, otherwise known as a megger. When a motor fails, it is often difficult to see why it failed just by looking at it.
Nidec motor corporation, referred to herein as the seller and the customer or person or entity. Actually voltage or current unbalance will produce too much heat thus damaging the motors. Maintenance and troubleshooting three phase induction motor. One is the electrical faults, such as the various faults of switches, buttons, fuses, electric brushes, stator winding, rotor, starting equipment and so on. The content here does not translate well to singlephase motors. Working through the system motor to disconnect,overloads, contactor and. Aug 31, 2000 generally speaking, threephase motors are less troublesome than singlephase motors, having no starting relays or capacitors to deal with. In the run winding of a split phase induction motor, how many poles are there. Therefore, learn about these phenomena, find out the cause, and then troubleshoot it. Ill include with troubleshooting method,technical guide,failure symptom and troubleshooting chart for single phase and three phase motor. How to troubleshoot motors and drives, starting at the inputs.
Of the three leads going from the starter to the motor, two were so loose that when i reached into pull on them both were removed wo a screwdriver. It is comparatively easy to obtain the required speed through the use of motors directly connected to the driven machine, through speed reducers, or the now more economical geared motors, or even through vbelt or chain or sprocket drive. Threephase dualvoltage motor insulation resistance testing threephase dualvoltage motors are used for most daytoday operations in todays industrial plants. Follow the steps below to check for the most common problems for threephase motors. How to troubleshoot a 3phase electric motor hunker. See the motor nameplate for proper connection diagrams.
Unlike an ohmmeter, a megger can measure highvoltage resistance values, which are generally the kinds of values you will encounter with three phase motors. First, the drive input is the ac power entering the drive from the mains second, the drive and its output, where the ac to dc converter, the dc filter, and the dc to ac inverter provide the three phase power to the motor how to troubleshoot motors and drives, starting at the inputs. These motors have fewer parts and are more sturdily built than their singlephase counterparts. It is essential that electric motors are installed by experienced, qualified and authorized. Electric motor maintenance and troubleshooting augie. The very first thing that you should do before starting any type of maintenance on a motor is a visual inspection, a lot of times the trouble can be found just by looking, because if the problem is that bad then it should be very obvious by observation. Top 4 causes of electric motor failure ibt industrial.
The best way to know for sure is check the voltage at the motor on all three legs. A motor placed in storage may or may not work, regardless of its physical appearance. Threephase motors are normally used in commercialtype operations. All threephase units are highstartingtorque motors and are capable of restarting against a load. The application by buyer shall not be subject to any implied warranty of fitness for a particular purpose. This might result in unexpected motor failures when critical services from such motors are required affecting availability of plants. Essential for anyone who needs to buy, install, troubleshoot, maintain, or repair small to industrialsize electric motors, this practical guide contains new information on threephase motors along with coverage of the. Franklin electric submersible motors are a waterlubricated design. Motor troubleshooting includes a motor connection box to practice handson skills such as troubleshooting faults in a dc motor and ac singlephase and threephase motors, evaluating dc electric motor commutator and brush health, and using a multimeter to test an ac motor startrun capacitor. They are used in situations where large power is required. Motor controls troubleshooting of electric motors free download as powerpoint presentation. Generally speaking, threephase motors are less troublesome than singlephase motors, having no starting relays or capacitors to deal with.
Motors brand products 6 warranty policy nidec motor corporation terms and conditions of sale. Identifying motor defects through fault zone analysis. It would not be unusual for a motor to single phase itself to death from a blown fuse, especially if the thermals were not correct. Current draw per phase at the motor s rated horsepower. Jun 22, 2018 single phasing creates a problematic situation for a threephase motor that can continue to operate by drawing more current thus more heat on the remaining two phases. The squirrel cage brand is the most popular and they perform various tasks wherever they are. How to troubleshoot a 3phase electric motor by daniel ray. It is true that single phase motors are less efficient substitute for 3 phase motors but 3 phase power is normally.
Induction motor fault heading fault causes remedies induction motor a no supply voltage b driven equipment jam c motor shaft jammed. Some standard lincoln electric motors are also capable of pws, yds or both as indicated in the following chart. Current draw at service factor load would approximate the amps listed times 1. Compared to singlephase motors, its unusual for a threephase motor to be in a lockedrotor situation. I will discuss further about troubleshooting guide for electric motors in my next part 2 of troubleshooting electric motors. The squirrel cage brand is the most popular and they perform various tasks wherever they are applied. Download pdf electric motor repair free usakochan pdf. Unique number identifies when the motor was manufactured. For brake motors, please refer to the information contained in weg 50021973 brake motor manual available on the website for information about permissible radial and axial shaft loads, please check the product technical catalogue. As a result these motors are less prone to malfunctions and tend to operate for many years. How to change the voltage on a century 115230 volt electric motor honeywell visionpro 8000 troubleshooting. The other is the mechanical problems, such as the problems of the bearing, fan blade, motor. Unit 16 electric motors washington state university. An indepth troubleshooting guide to help you with your ac electric motor issues.
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