In this video you will find out how to test 3phase induction motor. Perform a highpotential test on the excitation system in accordance with ansiieee standard. Standard for acceptance testing specifications for. Other motors that are included are 1phase induction motors, permanent synchronous motors and synchronous reluctance motors. The direction is changed by reversing the polarity on the leads. Several standards for testing electric machinery exist on a worldwide basis. Testing and commissioning procedure for electric motors eep. Startup currents can be 7 to 10 times larger than the steady state current used by a motor.
The basic steps in ascertaining the health of a threephase ac motor are given below. Since there is such a wide variety of these motors, it is impossible to describe all of them. Do not lift both the motor and driven equipment with the motor lifting means. All ac motors have the same basic components, a stator and rotor. Also, the heat is largely produced by internal elements of the dc motor, so most dc motors have a fan to reduce temperature. Pdma corporation has developed these portable motor testers. Pdf this paper describes a set of tests carried out on an induction motor for a 75 kw escalator. Testing the windings thru the diodes to check the resistance values, rotate the engines crankshaft to position the diodes on the generators shaft at 12 oclock. For three phase motors, connection type is either star y or delta ac motor winding continuity test using a multimeter, check the continuity of motor winding from phase to phase u to v, v to w, w to u. Servo motor repair load testing servo motor drive testing. Without the use of a threephase alternating current, an artificial phase displacement must be established. The following sections of the ansineta standard for acceptance testing specifications for.
Motor guide february 2014 low voltage motors motor guide. Jul 01, 2015 if the motor is completely unresponsive, no ac humming or false starts, take a reading at the motor terminals. Pdma corporation is the leader in the field of predictive maintenance, condition monitoring applications, and the development of electric motor test equipment for motor circuit analysis. Identify the different components of an ac motors and controllers. Check for burnt, damage to body or cooling fan or shaft. Dropforged eyebolts per american society of testing materials a489 or equivalent must be used.
Testing of induction motor december 30, 2018 february 24, 2012 by electrical4u demand of energy is growing day by day and along with it cost of energy rising abruptly, so now it is necessary that the health of large motors which consumes maximum power should be taken care off. Motor current signature analysis mcsa is a proven and accepted method for determining the condition of a motors current carrying components. Standard for acceptance testing specifications for electrical. Motor current monitoring and analysis mcsa is a straight forward tool to diagnosing problems with large inductive motors.
The ac induction motor is the most used electrical motor in industrial applications worldwide. Ieee std 1122004, ieee standard test procedure for polyphase. Learning objectives understanding the hipot test hipot test requirements hipot test considerations and failures arc detection. Dec 30, 2018 testing of induction motor december 30, 2018 february 24, 2012 by electrical4u demand of energy is growing day by day and along with it cost of energy rising abruptly, so now it is necessary that the health of large motors which consumes maximum power should be taken care off. An overview of ac induction motor testing in accordance with bs 4999 part 143 article pdf available april 1996. Disconnect the motor from the electronic speed controller esc and wind it up with a variablespeed batteryoperated drill, holding the stationary part and the three lead wires isolated. Ac dynamometers dynos provide accurate and repeatable dynamometer control under stringent operating conditions for various testing applications. Ac induction motors are one of the most common types of motors used in a variety of applications due to the fact that they run off of ac voltage which is readily available at every outlet.
In this test, a rated, balanced ac voltage at a rated frequency is applied to the stator while it is running at no load. The stator is the stationary coils in the motor where the current is produced to create the. If there is any problem, go to the motor, disconnect the cable thus isolate the motor and check the motor terminals again. Motordoc llc case studies and expert witness cases. Companies across the globe trust our reliability solutions, products, and services. The megger insulation tester is a small, portable instrument that gives you a direct reading of insulation resistance in ohms or megohms. This test can be done in your own workshop using simple hand tools and a specialized electric testing device. Testing can be conducted without interrupting the normal operation of the motor, and in fact should be performed when the motor is under a minimum of 70% load. How to test and check single phase electric motors. Chapter 10 test equipment, motors, and controllers navy bmr. An ac motor is an electric motor driven by an alternating current ac. Singlephase ac motors are the most common motors built. Mechanical energy what is an electric motor an electric motor is a device converting electrical energy into mechanical energy usually a torque.
Servo motor repair load testing we service well over a hundred servo manufacturers, with rush services available for rapid spindle, ac and dc servo motor repair. At servotech we are dedicated to providing the highest quality servo motor repair and refurbishment services, and have designed our servo repair process to ensure we return your. But smart companies understands is that what this means for maintenance programs is billions of dollars of lost revenue through increased motor repair costs, downtime, and waste in industrial and commercial companies. Locate the circuit breaker and ensure it hasnt tripped. How to test three phase ac motors learning electrical. Sep 03, 20 ac motors require slip to induce current in the rotor, and the amount of slip changes as the load on the motor changes.
Single phase magnetic induction motor with exposed rotor and coil after all, motors are always designed to carry out specific tasks. Standards for ac motors iec 600342 efficiency standards. If you suspect the fan motor is bad, the first thing you should check is the power to the motor and the power to the air conditioning unit. Measure resistance of machinefield winding, exciterstator winding, exciterrotor windings.
Induction motor is one of the most important motor used in industrial applications. Motordoc llc provides electrical machinery, electrical reliability and industrialcommercial consulting and training as well as the first continuous monitoring electrical and current signature analysis system and esa data collection systems. How to test motor start and motor run ac capacitor of ac fan and compressor. Induction motor, no load test, blocked rotor test, vibration test, temperature test, phase sequence test, insulation resistance test. This field affects the ac winding of the two main stator groups inducing an ac voltage in these windings that is available at the ac terminal block connections. Take readings at accessible points including disconnect s, the motor controller, any fuses or junction boxes, and so on, back to the overcurrent device output at the. Testing can be conducted without interrupting the normal operation of the motor, and in fact should be performed when. Ac motors are fairly basic devices that consist of one or more run windings and one or more start windings.
Section 7 of the ansineta standard for acceptance testing specifications for electrical power equipment and systems may be reproduced and used on a cut and paste basis for the particular type of equipment to be tested. We are constantly doing what everyone else just talks about. This is accomplished by a motor control, and the most common is a variable frequency drive vfd. There are many types of ac motors, but this course focuses on threephase induction motors, the most common type of motor used in industrial applications.
It should be noted that the scope of motor testing depends upon the motor type and size, this being indicated on the inspection forms. The theory used in the work was collected by studying literature on how. You can do this at the transformer, checking for a fuse in the lowvoltage circuit. One of the tips should touch the motors case while the other touches one of the exposed wire leads. This chapter will describe the most common types found on army watercraft.
Knowledge of the basics together with powerful new test. Ac motors ac motors are used worldwide in many applications to transform electrical energy into mechanical energy. This conversion is usually obtained through the generation of a magnetic field by means of a current flowing into one or more coils. If the power is fine, check to see if there is proper voltage. The three resistance readings of a threephase induction motor are compared and calculated to obtain the resistive imbalance. The efficiency value obtained from the different testing standards can differ by several percent. The test generally applies between 100 and 5,000 v or more. Mar 28, 2018 in this video you will find out how to test 3phase induction motor. Hipot test is the most common type of electrical safety. A protocol involving voltage level, time duration, intervals between tests and connection methods must be composed, taking into account the type and size of the equipment, its value and role in the production process and other factors. Custom motor test systems for ac motors, dc motors, aerospace motors, automotive motors, appliance motors, power tool motors, dentalsurgical motors and pump motors. One of the most important functions of the motor control is to properly start the motor. Conduct locked rotor tests on 3phase induction motors conduct noload tests on 3phase induction motors.
Ac engine dynamometers ac dynamometers dynos provide accurate and repeatable dynamometer control under stringent operating conditions for various testing applications. With a multimeter, measure the resistance between motor frame body and earth. Whether testing small electric tools, large electric motors, offroad diesel engines, marine diesel engines or powertrain components, we have a system thats right for you. If the motor makes a strange noise or something inside the motor gets hot, you have a shorted winding or a loose. Current ac motor has alternating current connected to the stator stationary windings. They only have two moving parts, the rotor and the start switch, which means that they are pretty easy to test and fix when you notice something is going wrong with the device. This is the problem encountered by singlephase induction motors.
An introduction to electric motors stmicroelectronics. How we measure reads a read is counted each time someone. Now, we can identify the problem to either the cable or the motor. Ieee standard test procedure for polyphase induction motors and generators 3 park avenue, new york, ny 100165997, usa ieee power engineering society sponsored by the electric machinery committee 4 november 2004 print. In order to change the speed of an ac motor, the frequency must be changed. Each phase to phase must have a continuity if winding is ok. Induction motor testing and evaluation summary as energy costs rise, more emphasis is being placed on determining the health of large inductive motors. Information, editorials and tech tips for you to use. Read the results on the tester, then repeat the same procedure with the other exposed wire lead.
Ac drives lead the technical revolution of electric forklifts. Another aspect in induction motor drives which has been researched recently is the use of multiphase induction motors where the number of stator phases is more than three. The no load test on an induction motor is conducted to measure the rotational losses of the motor and to determine some of its equivalent circuit parameters. Guide to low voltage motor testing test equipment depot. Several of these types of motor controllers may be contained in a single motor control center mcc which makes it easier to monitor and maintain the motor controls. For good insulation, the resistance usually reads in the megohm range. This test can be done in your own workshop using simple hand tools and a. The complete guide to electrical insulation testing. Jul 06, 2016 a dmm digital multimeter, such as this keithley dmm7510 from tektronix, is a musthave instrument for motor testing. Yes, i would like to receive emails from motordoc llc. The main purpose of the information that will be presented here is to describe many of the available tests that can be utilized under these different circumstances. For single phase motors, the expected voltage is about 230v or 208v depending whether you are using the uk or america voltage system.
Information guide for general purpose industrial ac small and medium squirrelcage induction motor standards. An ac motor of this type may be part of a pump or fan or. In addition to conventional squirrel cage rotor testing methods such as the growler test, also covered will be. Motor vibration shall be measured in a triaxial direction, i.
Well learn how to identify windings, check windings resistance and insulation resistance. Ieee std 1122004, ieee standard test procedure for. The ac motor commonly consists of two basic parts, an outside stator having coils supplied with alternating current to produce a rotating magnetic field, and an inside rotor attached to the output shaft producing a second rotating magnetic field. The rotor magnetic field may be produced by permanent magnets, reluctance. If the stator could only develop another current, slightly out of phase from the original current, a revolving field could be assimilated. The hipot test the dielectric voltagewithstand test is commonly known as the hipot test. Motor testing methods based on iec 6003421 p ll determined from residual loss 8. The megger insulation tester is essentially a highrange resistance meter ohmmeter with a builtin directcurrent generator. Perform an ac voltagedrop test on all rotating field poles. How to test and check single phase electric motors learning. A wide range of dmms are available to measure voltage, current, and resistance, depending on the motor power ratings. The motor is controlled by applying a voltage to the motor leads.
Ac motor testing performed with pdma mce offline tester resistive imbalance during this test a dc voltage is applied to the motor. If there is no voltage or reduced voltage, work back upstream. Aug 30, 2018 ac motors are fairly basic devices that consist of one or more run windings and one or more start windings. From this voltage the actual resistances of the windings are measured. Microsoft powerpoint ieee sf motor protection fundamentals. The maximum torque is limited by the current rating of the motor and it is obtained at zero speed startup.
If any particular phase fails the continuity test, your motor is probably burnt. Mar 29, 2019 check that the windings are not open or blown. For induction motors, the three most important ones are ieee standard 112, jec 37 japan and iec 600342. If you have a dc motor that is malfunctioning or drawing and bleeding power through the wires, there are tests that can be done to test the efficacy of the dc motor. In both types this produces rotation on the rotor armature. Electric motor testing explained the electricity forum. Inspection and test procedures for rotating machinery. As this is a grundfos publication, it is only natural that we should pay special attention to motors used for pumps although much of the information contained within these pages. How to tell if your ac fan motor is bad in 7 steps sansone ac. This standard specification describes the requirements for the contractor to overhaul ashore in a suitable repair facility an alternating current ac induction or synchronous motor removed from a coast guard vessel. During this test a dc voltage is applied to the motor.