Three phase induction motors tecowestinghouse motor company 5100 north ih35 round rock, tx. 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. If the motor doesnt rotate in twophase operation, find the reason for phase loss and eliminate it. Three phase induction motors are one of the most popular electric motors commonly found in processing plants or any manufacturing concern. 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.
Motors are susceptible to the gradual failure of their insulation resistance. Identifying motor defects through fault zone analysis. 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. First, the drive input is the ac power entering the drive from the mains. The solution will prevent damage from freezing in temperatures to 40 f 40 c. 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. Singlephase motors are found in a long and diverse list of devices like washing machines, mechanical clocks and generators. Three phase motors are normally used in commercialtype operations. As a result these motors are less prone to malfunctions and tend to operate for many years. This might result in unexpected motor failures when critical services from such motors are required affecting availability of plants. I will discuss further about troubleshooting guide for electric motors in my next part 2 of troubleshooting electric motors. It should be less than the full load rating stamped on the nameplate only true for three phase motors. Maintenance and troubleshooting three phase induction motor.
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 threephase motor, you will need a megohmmeter, otherwise known as a megger. I am leaving off several important parts of the story. These motors run conveyor belts, pumps, fans, and many other applications. How to test a threephase motor with a megger hunker.
Many standard motor starters contain overload relays which will not respond to this situation, however, threephase phase protection relays are available to protect motors. The modern electric motor installation the individual motor drive has practically replaced all other types. Industries of today use three phase motors widely in highpower applications. The fill solution consists of a mixture of deionized water and propylene glycol a nontoxic antifreeze. How to test a 3 phase motor is discussed in this article. Follow the steps below to check for the most common problems for threephase motors. Unlike an ohmmeter, a megger can measure highvoltage resistance values, which are generally the kinds of values you will encounter with threephase motors. These motors have fewer parts and are more sturdily built than their single phase counterparts. Single phase motors are found in a long and diverse list of devices like washing machines, mechanical clocks and generators. The squirrel cage brand is the most popular and they perform various tasks wherever they are. Unit 16 electric motors washington state university.
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. Some standard lincoln electric motors are also capable of pws, yds or both as indicated in the following chart. A fully uptodate, handson guide to electric motors. Dec 12, 2012 i will discuss further about troubleshooting guide for electric motors in my next part 2 of troubleshooting electric motors. Threephase dualvoltage motor insulation resistance testing threephase dualvoltage motors are used for most daytoday operations in todays industrial plants. All threephase units are highstartingtorque motors and are capable of restarting against a load. It is true that single phase motors are less efficient substitute for 3phase motors but 3phase power is normally. This textworkbook provides a framework for acquiring the technical knowledge and applied skills needed by maintenance electricians and those in related. By observing a few essential rules, you will ensure problemfree operation for many years. Ill include with troubleshooting method,technical guide,failure symptom and troubleshooting chart for single phase and three phase motor. Unique number identifies when the motor was manufactured. Check the reason for the unbalanced threephase power supply, if it is caused by the power voltage or the motor itself. Always keep hands and clothing away from moving parts. Check manual release to be sure it operates properly.
Working through the system motor to disconnect,overloads, contactor and. They are used in situations where large power is required. Installation and maintenance threephase induction motors. Generally speaking, threephase motors are less troublesome than singlephase motors, having no starting relays or capacitors to deal with. Electric motor maintenance and troubleshooting, 2nd edition kindle edition by hand, augie. Threephase motors are normally used in commercialtype operations.
Unlike an ohmmeter, a megger can measure highvoltage resistance values, which are generally the kinds of values you will encounter with three phase motors. 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. In the run winding of a split phase induction motor, how many poles are there. Induction motor fault heading fault causes remedies induction motor a no supply voltage b driven equipment jam c motor shaft jammed. How to troubleshoot a 3phase electric motor hunker. 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. Actually voltage or current unbalance will produce too much heat thus damaging the motors. An indepth troubleshooting guide to help you with your ac electric motor issues. Motors must always be accurately aligned, and this applies especially where they are directly coupled.
Nidec motor corporation, referred to herein as the seller and the customer or person or entity. This textworkbook provides a framework for acquiring the technical knowledge and applied skills needed by maintenance electricians and those in related electrical occupations. How to test three phase ac motors learning electrical. Motors brand products 6 warranty policy nidec motor corporation terms and conditions of sale. The content here does not translate well to singlephase motors. Top 4 causes of electric motor failure ibt industrial. How to troubleshoot motors and drives, starting at the inputs. Electric motors have energized circuits, exposed rotating parts and hot surfaces that may cause serious. 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. When a motor fails, it is often difficult to see why it failed just by looking at it. The application by buyer shall not be subject to any implied warranty of fitness for a particular purpose. All motors are suitable for full voltage or acrosstheline start.
Motor controls troubleshooting of electric motors relay. This textworkbook provides a framework for acquiring the technical knowledge and applied skills needed by maintenance electricians and those in. By observing a few essential rules, you will ensure problemfree operation for. The best way to know for sure is check the voltage at the motor on all three legs. Power supply test for three phase motors, the expected voltage for a 230400v system is 230v phase to neutral and.
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. Troubleshooting an electric motor that is suspected to have an electrical. One is the electrical faults, such as the various faults of switches, buttons, fuses, electric brushes, stator winding, rotor, starting equipment and so on. Dec 31, 2010 not knowing much on troubleshooting motors i procede to switch the thermal overload as requested. Electric motor maintenance and troubleshooting augie. Download pdf electric motor repair free usakochan pdf. Some standard lincoln electric motors are also capable of pws, yds or both as indicated in the following. See the motor nameplate for proper connection diagrams. Threephase motor troubleshooting electric motor fuse electrical. 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.
Electric motor maintenance and troubleshooting, second edition explains in detail how all types of ac and dc motors work. 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. Troubleshooting electric motors presents learners with a practical approach to troubleshooting motors and equipment in electrical systems. Here are the different test points in a typical threephase motor drive system figure 1. 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. Aug 31, 2000 generally speaking, threephase motors are less troublesome than singlephase motors, having no starting relays or capacitors to deal with. Threephase motors wyes and deltas 3, 6, 9, and 12 leads dual voltage connections. 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. Every good electrician knows the lead numbering sequence of three phase motors, or he has diagrams available for ready reference. Current draw at service factor load would approximate the amps listed times 1. How to change the voltage on a century 115230 volt electric motor honeywell visionpro 8000 troubleshooting. It is essential that electric motors are installed by experienced, qualified and. Electric motor troubleshooting industrial motor training. The following is some common faults and troubleshooting method of threephase induction motors for your reference.
Disconnect power to the motor before performing service or maintenance. We thank you for making this choice, and would ask you to read the contents of this manual. Download it once and read it on your kindle device, pc, phones or tablets. 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. It is true that single phase motors are less efficient substitute for 3 phase motors but 3 phase power is normally. How to troubleshoot a 3phase electric motor by daniel ray. Unit 16 electric motors objectives after studying this unit, the student will be able to state the purpose of an electric motor. The squirrel cage brand is the most popular and they perform various tasks wherever they are applied. Therefore, learn about these phenomena, find out the cause, and then troubleshoot it. Compared to singlephase motors, its unusual for a threephase motor to be in a lockedrotor situation. Motor controls troubleshooting of electric motors free download as powerpoint presentation. To measure the resistance in a three phase motor, you will need a megohmmeter, otherwise known as a megger. That way you can rule out the starter and all the conductors to the motor. Use features like bookmarks, note taking and highlighting while reading electric motor maintenance and troubleshooting.
Motors must always be accurately aligned, and this applies especially where they are. Take input voltage to the motor using the volt ohmmeter. Threephase dualvoltage motor insulation resistance testing. Handson and lecture the participant is able to learnbydoing in the course. A motor placed in storage may or may not work, regardless of its physical appearance. The other is the mechanical problems, such as the problems of the bearing, fan blade, motor. Electric motor maintenance and troubleshooting, 2nd edition. 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.
Threephase motor troubleshooting free download as pdf file. 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. Check the voltage in all three phases at the motor. 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. Franklin electric submersible motors are a waterlubricated design. Electric motor maintenance and troubleshooting, 2nd. Some standard lincoln electric motors are also capable of pws, yds or both as.
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