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