Induction motor efficiency test methods ieee xplore. Pdf test equipment for determining performance of electric motors. Best practice today is applying vsd retrofits and of course new. Efficiency testing of electric induction motors loading ftp site.
Each of these specifications includes a variety of basic methods for determining efficiency based on motor size and availability of test equipment. Iec618009 system standards as a tool to boost the efficiency of. The specific objectives of the motor carrier efficiency study mces include the following. In view of this, for selecting high efficiency motors, the following can be done. Permanent magnet pm motors are used a lot in applications where efficiency is important and size is a restriction, as they have a higher power density because the magnet supplies the rotor field rather than having the losses in the rotor these pm motors require an inverter and a lot of cooling and care when operating in different modes. Performance of the motor needs to be evaluated at site as part of the energy auditing or efficiency determination program. Determination of runtime efficiency for motor in actual site conditions and conducts energy audit study. We recommend that you survey and test all motors operating over hours per year.
This manual covers squirrel cage rotor motor where the rotor consists of a. The various losses in an induction motor are shown using the following figure fig7. Evaluation ofmarkets andefficiency offractionalpolyphase. Having these logged values synchronized with the data would be of interest for researchers to know. Report on international efficiency efficiency classes for. Figure 3 general trend of motor efficiency based on motor loading. Report on international efficiency efficiency classes for low. Iec 6003421 standard on efficiency measurement methods. Energy efficiency considerations in pumps and pump stations. The motor carrier efficiency study 2007 annual report to congress.
Small changes in the calculation formulas of the standard have no significant influence in the efficiency itself. This leads to issues like a very efficient motor but poor efficiency in the inverter. The efficient use of electricity is not just a nice to have. Record all nameplate information for the induction motor. The electric energy that is input into the device is converted to mechanical energy by the motor. This test method figure 2 curve shown illustrates general trend of motor efficiency versus motor size for standard and premium efficiency motors. Pdf a new test method for determination of induction.
The readers who will find this guidebook most useful are those who need a basic, nonengineering overview of generalpurpose motors, motor efficiency and motor management fundamentals, particularly in the context of optimizing motor system performance. Most electric motors are designed to run at 50% to 100%. Table 1 eccemep minimum efficiency standards for 4pole motors kw eff2 eff1 3 82. These requirements serve to determine the baseline energy performance on motor.
The test would be done by quickly loading the motor from no. To obtain short circuit current and its power factor angle, block rotor test is performed on the motor. Motor efficiency improvement epact was passed in 1992 but motor efficiency provisions took effect in 1997. The motor is controlled applying a voltage on the motor leads. Department of energy doe office of energy efficiency and renewable energy eere with support from the copper. The most commonly referred to test methods are the following. The typical efficiency curve of the induction motor is shown in fig. A motor s efficiency tends to decrease dramatically below about 50% load. The accepted domestic test for electric motor efficiency is the one defined by ieee standard 112 method b. For comparison, epact efficiency standards for 20 hp motors with open drip. Motor efficiency is the ratio of mechanical energy output to electrical energy input. The load angle is almost constant, and it is about 90 allowing the maximum efficiency current vs. Maximum efficiency is usually near 75% of rated load. The method used is based on field testing of motors ieee std 1121984, jec 37, iec 342, isi 4889.
One such technology is the pdma corporation mcemax motor test equipment powered by mcegold software. The test procedure provides a meansof estimating the average temperatures of the stator winding at the fullload and. The following example shows how to automate the mcsa test. Test methods for determing the impact of motor condition. The energy efficiency of electric motors is defined in the international standard on efficiency classes for motors. The direction is changed reversing the polarity on the leads. At lower values of resistive load, the motor heated up more rapidly than at the higher values of load. This technology combination conducts a complete electrical analysis of six. The audience who will find this guidebook most useful are those that need a basic, nonengineering overview of general purpose motors, motor efficiency, and motor management fundamentals, particularly in the context of optimizing motor system performance. This paper presents the revised methods and compares this test procedure with iec 342 and jec37. Furthermore, there is a need to establish a level platform for motor manufacturers globally where they can produce electric machines according harmonized standards. The changing landscape of electric motor efficiency. S1 continuous load and electric motors that are designed for other.
Most methods generally rely on models that does not account for dynamic variations of motor conditions. Thus, a 10horsepower hp motor has an acceptable load range of 5 to 10 hp. Efficiency testing of a motor defined and described in this code include the following. New testing approach matches real world conditions. Motor efficiency standards for other 2, 4, 6, and 8 pole motors can be found in douglass 2005. Environmental challenges, which include climate change, global warming and greenhouse gas emission have been fuelling the need to increase energy efficiency in electrical rotating machinery. An induction motor efficiency test program was undertaken by the north carolina alternative energy corporation to form an independent basis for recommending energy efficient motors to industry in. Iec stands for the international electrical commission, a global standardization organization. The video shows research carried out when researching on increasing the electricity energy efficiency of electrical motor systems during a research project f. The high efficiency motor with a smaller size may be used providing that the payback period is worth. While meps are now most often based on the motor efficiency classification and efficiency test methods in iec standards, the process and requirements for certification and compliance vary greatly from country to country, including test standards, laboratory accreditation, sampling, test process and labelling.
Test to obtain more reliable values ranges of both wattmeter should be 10a, 250v for blocked rotor test. Figure 3 general trend of motor efficiency based on motor. Commercial, institutional and, particularly, industrial operations use substantial amounts of power for electric motors. Similarly the range of ammeter and voltmeter during blocked rotor test, 10a, 250v. Inspect if the following area are in ground wiring and insulation wiring, inspect preventive apparatus and control circuit if they are working.
The motor is mounted in a test rig that allows one to control the torque applied to the motor shaft and to measure both rpm and torque. A slightly less efficient motor can be worthwhile, if it increases the efficiency of the motor drive. The iec has contributed to the definition of energyefficient electric motor systems through the internationally relevant test standard iec 6003421 for electric. Practical motor efficiency assessment and improvement. The same motor test ed by different methods and by same methods by different manufacturers can give a difference of 2 %. In this paper a new test method is proposed to determine the induction motor efficiency by an equivalent circuit with two rotor loops. Improving pumping efficiency operate smart pump as slowly as possible utilize storage to level out pumping rate eliminate throttling fix stuff test pumps regularly inc electrical measurements visual inspection of interior modify or replace impeller to match conditions replace old motors. The iec 60034301 efficiency standard applies to lowvoltage threephase ac squirrel cage motors in accordance with the following criteria. The results show that the tested efficiency of the pm motor is significantly higher than the best efficiency now available for induction motors, and. A comparison of induction motor efficiency test methods according to the iec 6003421 and ieee 112 standards is presented in this paper.
Apr 23, 2019 2 for polyphase small electric motors of greater than 1 hp and electric motors, either section 6. Ieee standard 112, the recognized test procedure in the united states, has recently been revised. Permanent magnet motor with tested efficiency beyond ultra. Motor efficiency testing protocols differ around the world, and their application on any. A test procedure to measure the performance in a manner suitable for direct comparison to published induction motor efficiencies is included. Efficiency test method b covers the type of procedure used in this research. Noload test balanced voltages are applied to the stator terminals at the rated frequency with the rotor uncoupled from any mechanical load. Ieee std 1122004, ieee standard test procedure for polyphase. The excess energy is dissipated as heat into the surrounding tissue and blood. Code of practice specifies the minimum motor efficiency for singlespeed threephase totally enclosed motor. Iec 60034 part 30 efficiency classes of line operated ac motors ie code. The amount of power out of a motor is dependent upon its efficiency figure 6.
Using the analysis results, divide your motors into the following categories. A test will have thermocouples for monitoring temperatures which are logged or sent to a control system for shutdown. Thus, the only power absorbed by the electric motor is the loss incurred in making the conversion from electrical to mechanical energy. A motor with an efficiency of 80% will draw an electrical power of 10. Motor current speed analysis implementation example as shown, mcsa is a key tool to evaluating the health of inductive motors it also can be automated for more efficient testing. Even a small voltage unbalance of 1% can reduce motor efficiency by the same amount as 1% of efficiency on a large motor can cost up to five times the purchase price of the motor in additional energy costs over its life. Whereas speed measurement is a relatively simple procedure requiring. Iec 6003421 standard on efficiency measurement methods for. Test stand systems flexible test systems for maximum efficiency.
Test methods, marking requirements, and energy efficiency levels for treephase induction. Determining electric motor load and efficiency department of energy. This approach is a logical extension of the method of the traditional equivalent circuit. Department of energy doe office of energy efficiency and.
A standard dol squirrel cage induction motor rated at 5. The motor carrier efficiency study 2007 annual report to. Induction motor efficiency measurement 1 introduction 2 methodology. Ieee std 1122004, ieee standard test procedure for. This technology combination conducts a complete electrical analysis of. Application note electric motor efficiency and reliability global test. Torque and load angle the output torque of an electrical motor depends on the intensity of the rotor and stator magnetic fields and on their phase relation. Induction motor efficiency test methods ieee journals. The changing landscape of electric motor efficiency standards. Hitachi motor hitachi high efficiency motors sme273 1215 technical managements special instruction inspect the machine before use please inspect the following area before turning on the switch. Best practice manual electric motors prepared for bureau of energy efficiency, under ministry of power, government of india hall no. Internationally, there is a standard which stipulates the energy efficiency of low voltage ac motors, namely the international efficiency ie. Also the maximum efficiency achieved within the tested load points i3% as shown s 92. Efficiency testing of electrical machines and electrical.
You should also make a dc measurement of stator winding linetoline resistance using a dmm. Pdf efficiency testing of pump and motor lab mel george. For example, assuming that no transmission losses occur. Test methods for determining efficiency of cage induction motors. The maximum output torque, and then the maximum efficiency. Ieee standard 1121984 standard test procedure for polyphase induction motors and. From figure, the maximum torque developed by the motor over 5 the load range tested was about 40nm. Evaluation ofmarkets andefficiency offractionalpolyphase motors. Although high or premium efficiencies may have only a few percentage points better. Dc motor performance curves can be generated under various conditions. D all test pro, llc old saybrook, ct 06475 abstract this article discusses the financial impact of motor condition on electric motor efficiency and reliability by. The manual motor testing station was assembled to increase student understanding of motor performance, with primary emphasis on efficiency and power factor. The portion of electric energy that is not converted to mechanical power is converted to heat, which is mostly unusable. Most electric motors are designed to run at 50% to 100% of rated load.
Maintenance special instruction hitachi highefficiency motors. A manually operated motor testing station provides students an opportunity for handson laboratory exercises in determining efficiency and. The electric motor efficiency is defined as how efficient it is to make the conversion. An existing standard efficiency motor larger than 1. The performance rating of a motor as specified on its name plate is determined by the output horsepower it can continuously produce as. Adoption of energyefficient electric motors and motor systems. Electrical input measurements at actual load, if the motor is connected to load 5. Pdf a new test method for determination of induction motor. Electric motors have to meet certain minimum efficiency require ments if they are.
Test procedure for polyphase induction motors and generators. Noload test, blocked rotor test the equivalent circuit parameters for an induction motor can be determined using specific tests on the motor, just as was done for the transformer. The test would be done by quickly loading the motor from noload to locked rotor stall using a fixed. Reference standards for test methods and energy efficiency calculations.
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