3.4 short-time rating for example, one hour mechanical output that the motor can deliver on the test bed for the stated time without exceeding the limits of temperature rise given in Ta
Exchange of information
The motor and converter designers shall collaborate to produce all the technical information necessary to ensure that the combined unit will meet the requirements of this part of IEC 60349
To fulfil this requirement, the motor designer shall provide the converter designer with all the information necessary to fully evaluate the interaction between the motor and the converter
The converter designer must supply the motor designer with essential characteristics, including the line-to-line output voltage (with repetitive voltage peaks), current, fundamental frequency, harmonics, and power across the entire application range, particularly at the maximum and minimum contact-system voltage values.
The documents recording this exchange of information shall form an integral part of the specification of the motor and of the converter
NOTE 1 For more information refer to IEC 61287-1, 5.3.1.1
NOTE 2 The length of cable run between motor and converter and the effect on peak voltages seen at the motor terminals should be considered
NOTE 3 For information about wave fronts and the impact to the motor see IEC 60034-17.
Specified characteristics
Motor specifications must generally include characteristic curves that align with the relevant clauses of this section These curves, referred to as "specified characteristics," should be plotted according to the designed operating limits of each variable Unless otherwise agreed upon by the user and manufacturer, the characteristics must reflect the machine's performance at the nominal supply voltage defined in Annex D and should be provided to the user prior to placing the motor order.
Declared characteristics
Declared characteristics are derived from the results of type tests carried out in accordance with 8.2.1 and shall meet the requirements of 8.2.2
Unless otherwise specified, the characteristics of electromagnetically identical motors must match those of previously manufactured motors for the same user or application In this scenario, compliance with these characteristics can be verified through routine testing alone.
Efficiency characteristics
Efficiency characteristics must consider losses due to harmonics in the converter supply Additionally, power used for the excitation of synchronous motors should be included in the losses unless it is classified as an auxiliary load, in which case this omission must be clearly stated in the characteristics.
Traction motor characteristics
The traction motor's characteristics must include converter-fed variable frequency data, detailing line-to-line voltage, current, frequency, mean torque, and efficiency across the entire speed range Asynchronous motor characteristics should indicate slip, while synchronous motors must display excitation current Voltage curves need to represent the root-mean-square value of the fundamental component, and current curves should reflect both the root-mean-square value of the fundamental component and the total root-mean-square value Additionally, for motors operating in braking mode, similar characteristics should illustrate torque input and electrical output as functions of motor speed.
NOTE 1 Subclause 5.1 refers to the need for the exchange of information between the designers of the motor and of the converter
Tractive effort at rail and vehicle speed can serve as an alternative to motor torque and speed, requiring the specification of gear ratio, wheel diameter, and transmission losses If conventional values are applied, they must align with the standards outlined in Figure B.1.
NOTE 2 Clause 1 refers to the need to consider the effect on parallel-fed motors of differing wheel diameters and of weight transfer between axles.
Auxiliary motor characteristics
The auxiliary motors must exhibit converter-fed characteristics, detailing the line-to-line voltage, current, speed, and mean torque as functions of motor output across all operating frequencies For motors that function at continuously variable frequencies, characteristics should be illustrated for both maximum and minimum frequencies only.
Asynchronous motors exhibit slip, while synchronous motors display excitation current Voltage curves represent the root-mean-square value of the fundamental component, and current curves indicate both the root-mean-square value of the fundamental component and the total root-mean-square value Additionally, the characteristics must consider extra losses due to supply harmonics, and the efficiency at the guaranteed rating should be clearly stated.
Alternatively, the characteristics may be plotted as a function of speed
NOTE Subclause 5.1 refers to the need for the exchange of information between the designers of the motor and of the converter
Nameplate
All motors covered by this part of IEC 60349 shall carry a nameplate including at least the following information: a) Manufacturer's name b) Motor type designation c) Motor serial number d) Year of manufacture
Every motor must have a serial number stamped on both the stator and rotor Additionally, motors intended for unidirectional rotation should feature an arrow that clearly indicates the direction of rotation.
NOTE The motor serial number and rotation arrow should be easily readable when the motor is installed in the vehicle.
Terminal and lead marking
Terminal and lead markings shall be in accordance with IEC 60034-8 unless otherwise agreed
Test categories
General
There are three categories of tests:
NOTE See Clause 1 on duplication of tests.
Type tests
Type tests are designed to validate the ratings, characteristics, and performance of new motor designs These tests must be conducted on one motor from each new design, typically selected from the first ten units produced If there are any changes in the manufacturing location or method, refer to section 7.1.2.4 for guidance.
Before testing begins, the manufacturer must provide the user with a test specification detailing the tests required to ensure compliance with the standard After the type tests are completed, the manufacturer is obligated to deliver a comprehensive test report to the user.
7.1.2.2 Type tests on converter supply
For optimal testing, each motor should ideally be powered by its designated converter during type tests Alternatively, a supply that closely mimics the waveform and harmonics of the vehicle's converter can be utilized.
When multiple motors are powered in parallel by a single converter, it is essential to conduct a type test on one motor This test should utilize a power supply that closely matches the waveform and harmonics of the vehicle converter's output.
Upon user request, the manufacturer is required to show the similarities between the test and service supplies, as well as to explain how any differences may impact the motor's performance.
Unless otherwise agreed, the type test shall be repeated if the electrical output characteristics of the converter are changed
7.1.2.3 Type tests on sinusoidal supply
This test is to provide a reference for the characteristics of a machine
The test shall include a temperature rise test at a rating agreed between the manufacturer and the system responsible
Manufacturers have the discretion to determine voltage, frequency, torque, ventilation, and test duration; however, the test must last a minimum of 1 hour and operate within values that do not exceed the normal stress levels experienced by the machine in service.
The test parameters shall be maintained for any subsequent test on that design of machine The temperature rise measurements shall be carried out as detailed in 8.1
A full type test is not necessary if the manufacturer provides a complete type test report for a motor with the same electromagnetic design and equal or higher rating, subject to agreement and the results of both the sinusoidal supply type test and routine test being within established tolerances This provision also applies to repeat orders and any changes in manufacturing location or method.
Routine tests
Routine tests ensure that a motor is properly assembled, can endure necessary dielectric tests, and functions effectively both mechanically and electrically.
Routine tests outlined in Clause 9 are typically performed on all motors; however, users and manufacturers can mutually agree to an alternative testing procedure before placing an order This is particularly applicable for motors manufactured in large quantities under stringent quality assurance protocols, potentially allowing for reduced routine testing or full tests on a random sample of the produced motors Regardless of the agreed-upon procedure, all motors must undergo the dielectric tests specified in section 9.5.
Investigation tests
Investigation tests are optional assessments conducted to gather extra information and should only be performed if there is prior agreement between the user and the manufacturer before ordering the motors The outcomes of these tests will not affect the acceptance of a motor unless there is a mutual agreement on this matter.
Summary of tests
Table 1 lists the tests required for compliance with this part of IEC 60349
Test category Tempera- ture rise
Short-time thermal test/heat run
Over- speed Dielectric Vibration Noise
All motors, including those type tested, shall be routine tested a Optional tests, subject to agreement between user and manufacturer
Temperature-rise tests
General
The tests shall be carried out at the guaranteed ratings of the motor
The rated mechanical output of a motor can be determined either directly or indirectly at the motor shaft Alternatively, it can be obtained without direct measurement by supplying the motor with the specified voltage, current, and frequency that correspond to the declared characteristics for achieving the rated mechanical output.
To expedite the time required to achieve a steady temperature during continuous rating tests, the test can begin under increased load or reduced ventilation However, it is essential to maintain the rated conditions for a minimum of 2 hours or until it is confirmed through appropriate methods that steady temperatures have been attained.
NOTE Steady temperature is defined as a change in temperature of less than 2 K during the final hour of the test.
Ventilation during rating tests
Motors must be tested under service-like ventilation conditions, ensuring that all components affecting temperature rise, such as ducting and filters considered part of the vehicle, are in place or that equivalent conditions are provided.
For forced ventilation cooling, it is essential to measure the static pressure and airflow at the motor's inlet to create a table that illustrates the relationship between these two variables.
Typically, cooling systems that rely on vehicle movement are not included; however, in specific situations, such as with fully enclosed traction motors where cooling is crucial, such systems may be implemented with mutual consent between the user and the manufacturer.
Measurement of temperature
The temperature shall be measured in accordance with Annex A.
Judgement of results
The temperature rises of the windings and slip rings at the “commencement of cooling” as defined in A.4 shall not exceed the values given in Table 2.
Limits of temperature rise
The different thermal classes of insulation systems are defined in IEC 60085
Table 2 outlines the allowable temperature rise above the cooling air temperature, as measured on the test bed, for windings and components insulated with materials from the current thermal classes used in motor construction relevant to this section.
If different parts of the same machine have different thermal classes of insulation, the temperature-rise limit of each part shall be that of its individual thermal class
Table 2 – Limits of temperature rise for continuous and other ratings
Thermal class of insulation system
Rotating field windings of synchronous motors
Cage rotors and damping windings Electrical thermometer The temperature rise shall not be sufficient to endanger any windings or other parts
For totally enclosed motors, the limits above are increased by 10 K
When motors are subjected to heat from an engine or other sources, users and manufacturers may agree on adopting temperature rises that are lower than those listed in Table 2.
Short-time overload test
If short-time overload ratings are specified, they shall be verified by one or more tests carried out as follows
To determine the initial temperature rise from the previous temperature-rise test, continue plotting the cooling curve for the critical winding until the extrapolated temperature rise reaches the "start" value indicated in Table 3, within a maximum of 5 minutes from the last reading The specified overload should then be applied under normal ventilation conditions at this predicted time and maintained for the designated duration The test will conclude with the measurement of the temperature rise as outlined in section 8.1.3.
If the temperature increase measured is within 20 K of the final value listed in Table 3, adjustments to the rated current or duration can be calculated to achieve the specified temperature rise However, if the measured temperature rise exceeds the Table 3 value by more than 20 K, the test must be redone with revised current or duration values.
Table 3 – Temperature rises for short-time overload ratings
Thermal class of insulation system Part
Rotating field windings of synchronous motors At end of test 130 K 155 K 180 K 200 K 220 K 250 K NOTE 1 For totally enclosed motors, the temperature rises given above are increased by 10 K
NOTE 2 An alternative method of obtaining the starting temperature rise may be employed if agreed between manufacturer and user
NOTE 3 If agreed between user and manufacturer, the temperatures of other motor parts (e.g the rotor cage, damping windings, bearings, etc.) may be measured.
Characteristic tests and tolerances
General
Compliance tests will involve measuring the electrical input to the motor and its mechanical output The output can be measured directly or calculated based on the output of a driven electrical machine with a known efficiency.
Alternatively, and if agreed between user and manufacturer, either the output or input of the motor being tested may be derived by summation of the losses
Load tests must be conducted with the motor at or near the reference temperature, and any significant deviations should be corrected Adequate test readings are essential to accurately plot the motor's declared characteristics.
The electrical input to the converter shall be measured by an agreed method, but it shall not influence the acceptance of the motor
The electrical input to the motor can be adjusted through mutual agreement between the motor and converter manufacturers, provided that the temperature increases of all components remain within their specified limits during operation at the guaranteed rating, and that the motor losses comply with the tolerances outlined in section 8.2.2.
The specified excitation current of a synchronous motor may be similarly modified
The tests shall be carried out in only one direction of rotation
Instruments measuring the motor's input waveforms must accurately indicate current, voltage, and power values to ensure compliance with specified tolerances.
Tolerances
The declared torque at any electrical input must be at least 95% of the specified value within the range between maximum torque and 90% of maximum speed.
The motor losses at the guaranteed rating shall not exceed the value derived from the specified characteristic by more than 15 %
The temperature rise from the sinusoidal supply type test (see 7.1.2.3) where applicable, shall not vary by more than ±8 % or ±10 K, whichever is the highest, from the original type test
The torque shown in the declared characteristics at the guaranteed rating shall be not less than the specified value
The current at the guaranteed rating shall not exceed the specified value
The current to produce the specified starting torque shall not exceed the value specified to the converter manufacturer in accordance with 5.1.
Overspeed test
All converter-fed motors must undergo an overspeed type test, where they are operated for 2 minutes at 1.2 times their maximum working speed when hot, as specified in section 3.16 Alternatively, rotors can be tested prior to assembly in the stator, provided they are heated to a temperature similar to that achieved at the end of the guaranteed rating test In both scenarios, measurements should be recorded before and after the test to assess any distortion of the rotor.
Vibration tests
A quantitative vibration measurement is to be taken as a type test Where a machine incorporates an integral gearbox, the gear assembly must be removed or gearbox replaced by a supporting end shield
For vibration measurement during type testing, the machine can be directly placed on the test board without the need for mounting equipment The vibration velocity must remain within 3.5 mm/s at speeds up to 3,600 rev/min, while for speeds exceeding 3,600 rev/min, the velocity should be below 5.25 mm/s.
If the machine design has no fixed bearing the longitudinal velocity of vibration could be excluded
For additional information see IEC 60034-14.
Measurements on variable speed machines shall be taken at a number of speeds covering the whole working range
Excessive vibration velocities may occur due to resonances in the test mountings; however, these should be ignored if they do not align with a specific working speed and if the overall velocity levels remain within acceptable limits across the speed range.
Should such a resonance occur at a discrete working speed, the test shall be repeated with an alternative mounting arrangement
NOTE The effect of externally generated vibrations on the machine is outside the scope of this document Reference should be made to IEC 61373
General
Routine tests shall be carried out in one direction of rotation using a sinusoidal supply at power frequency or at a frequency used in service
The use of a waveform different from sinusoidal must be agreed between the manufacturer and the user
Different tests, such as no-load and locked rotor tests, can utilize varying frequencies, but once set, these frequencies must remain unchanged The reported values for the test points should represent the average results from four motors, including one that has undergone type testing To minimize the impact of temperature fluctuations, all tests should be conducted in a consistent sequence across all motors It is important to note that efficiency measurements and braking mode tests are not necessary.
To ensure consistency in a series, a sinusoidal temperature rise type test may be conducted at random or predetermined intervals, as agreed upon by the user and manufacturer The tolerances for this testing are specified in section 8.2.2.
Short-time heating run
This test is only applicable to wound rotor machines
All motors, except those that have passed the sinusoidal type test, must be operated briefly to achieve a stator winding temperature of at least 150 °C by the conclusion of the test.
Attainment of the temperature shall be verified by measurements on the first two motors tested
If the conditions are altered, the verification shall be repeated Once attainment of the temperature has been verified on two motors, no further temperature measurements are required.
Characteristic tests and tolerances
Asynchronous motors
Asynchronous motors must undergo testing under two specific conditions: first, they should be evaluated at no-load using a voltage that generates the maximum magnetic flux within the motor, applicable at any speed ranging from 10% to 100% of the declared characteristics.
The current must remain within ±10% of the declared value as specified in section 9.1, with a locked rotor at a voltage that approximates the guaranteed rated current This voltage will be determined during the initial motor test and will be applied to all subsequent tests.
The current shall not vary from the declared value established in accordance with 9.1 by more than ±5 %.
Synchronous motors
Synchronous motors must undergo testing under specific conditions, including operation as a generator to generate an open-circuit voltage that aligns with the maximum magnetic flux present in the motor at any point on its declared characteristic.
The excitation current must remain within ±15% of the specified value as per section 9.1 Additionally, it should be driven on short circuit with the excitation set to achieve the guaranteed rated current.
The excitation current shall not vary from the declared value established in accordance with 9.1 by more than ±5 %.
Overspeed tests
Overspeed routine tests shall normally be carried out only on wound rotor motors, but it may be agreed to extend them to cage-type motors or omit them altogether
Motors undergoing an overspeed test must operate for 2 minutes at 1.2 times their maximum working speed when hot, as defined in section 3.16 Following this, they are required to pass the dielectric tests outlined in section 9.5.
When conducting routine overspeed tests, it is essential to take precautions, such as ensuring that the test speed does not fall below the maximum working speed, to prevent potential damage to rolling bearings caused by high-speed operation under no-load conditions.
Dielectric tests
Tests are typically conducted using alternating current (a.c.) with a near sinusoidal waveform and a frequency range of 25 Hz to 100 Hz However, direct current (d.c.) testing can be utilized if there is prior agreement between the user and the manufacturer before the order is placed.
The test voltage must be sequentially applied between the windings of each circuit and the frame, while all other circuit windings are connected to the frame This full voltage application is only for new motors with all components assembled, simulating normal operating conditions The testing should be conducted with the motor at operating temperature, immediately following the completion of the routine tests outlined in previous sections.
The test voltage must be the maximum value specified in Table 4 for the selected test method and should be applied gradually, starting at no more than one-third of the final value Once this final voltage is achieved, it must be sustained for a duration of 60 seconds.
1 All windings other than group 2
2 Excitation windings of synchronous motors
10 U e a.c or 17 U e d.c., with a minimum of 1 500 V a.c or 2 550 V d.c and a maximum of 3 500 V a.c or 5 950 V d.c
U dc is the highest mean voltage to earth which can be applied to the d.c link when the contact system is at its maximum voltage and the machine is motoring
U rp represents the maximum repetitive peak voltage to earth that can be applied to the machine winding while the contact system operates at its highest voltage during motoring conditions For a detailed definition of repetitive peak voltage, refer to section 3.14.
U rpb is the maximum repetitive peak voltage to earth which can appear on the winding when the machine is braking
U e is the maximum mean value of the excitation voltage
If neither the d.c link nor the motor windings are normally earth referenced, then U dc , U rp and
U e shall be taken as the highest voltages to earth that can appear on their respective circuits, should any point on them become connected to earth
A lower value for repeated tests shall be agreed between user and manufacturer of the motor
Remark: The value used to test the converter (see IEC 61287-1) shall be lower or equal to the value used to test the motor
NOTE This subclause defines requirements for the serial test Please consider IEC 60034-18-41 for the qualification of a winding system.
Vibration tests (imbalance)
Each machine must be inspected for vibrations caused by imbalance Typically, it is sufficient to show that a machine operates smoothly while mounted on the test bed and powered at the supply frequency If the machine includes an integral gearbox, the vibration assessment can also be performed with the gearbox installed during routine testing.
In applications where machine vibration is considered critical, if agreed between user and manufacturer, the tests detailed in 8.4 can be carried out on each machine
A.1 Temperature of the motor parts
The temperature of insulated windings shall be measured by the resistance method, that of permanently short-circuited windings and that of slip rings by the electrical thermometer method
No correction shall be made to the measured temperature rises if the temperature of the cooling air is between 10 °C and 40 °C during the test
If the cooling air temperature is outside these limits during a type test, a correction to the measured temperature rises may be agreed between user and manufacturer
Before conducting a short-time test, it is essential to verify that the winding temperatures are within 4 K of the cooling air temperature using a thermometer or resistance measurements When calculating the temperature rise of the windings, any initial temperature difference of up to 4 K should be adjusted accordingly: subtract from the result if the winding is hotter, or add to it if it is cooler.
In this method, the temperature rise of a winding is determined by its increase in resistance during the test
For copper windings, the temperature rise at the end of a test is determined by the following formula: temperature rise = t 2 – t a = R
(235 + t 1 ) – (235 + t a ) where: t 1 is the initial temperature, of the winding in degrees Celsius;
R 1 is the resistance of the winding at temperature t 1 ; t 2 is the temperature, of the winding at the end of the test in degrees Celsius;
R 2 is the resistance of the winding at the end of the test; t a is the temperature of the cooling air at the end of the test in degrees Celsius
NOTE For materials other than copper, the value 235 in the above formula should be replaced with the reciprocal of the temperature coefficient of resistance at 0 °C for the material
In this method, the temperature is determined by means of electrical thermometers applied to the hottest accessible spots of the relevant parts immediately after the motor is stopped
A.2 Temperature of the cooling air
For totally enclosed motors, the cooling air temperature shall be measured by not less than four thermometers distributed around the motor and spaced between 1 m and 2 m from them
The cooling air temperature must be measured at the motor's entry point, and if there are multiple entry points, the temperature should be the average of all measurements taken at each point.
To ensure accurate temperature readings, thermometers must be shielded from radiated heat and drafts, allowing them to reflect the true air temperature around the motor Additionally, it is essential to implement measures that minimize fluctuations in the cooling air temperature to prevent errors.
The cooling air temperature at the conclusion of a test will be determined by averaging measurements taken at roughly 15-minute intervals during the final hour of a continuous rating test or throughout the entire duration of a short-time test.
Cold resistance measurements should be conducted with the same instruments used for hot measurements, without the need for repetition at the start of each test The winding temperatures should be recorded as their surface temperature via a thermometer during the resistance measurement, ensuring that the difference from the ambient air temperature does not exceed 4 K.
Hot resistance should be measured promptly after the motor is stopped at the end of the test This measurement can be conducted using the voltmeter and ammeter method (volt-ampere method), a bridge, or other appropriate techniques It is essential to use the same method for all readings on a specific winding, including the initial cold measurement.
When utilizing the voltmeter and ammeter method, it is essential to ensure that the current is sufficiently high to achieve the required accuracy while avoiding any impact on temperature rise Typically, maintaining a current value that does not exceed 10% of the rated current will satisfy this condition.
A.4 Stopping of motors and time of “commencement of cooling”
At the end of a test, the motor shall be stopped in as short a time as possible
A preferred braking method involves testing the motor without current In this scenario, the "commencement of cooling" is defined as the moment the main circuits are opened just before braking, with any additional ventilation also halted at that time.
If a direct method is not feasible, alternative approaches that allow the test motor to carry current can be employed, as long as they ensure rapid motor stoppage and maintain a relatively constant load current during braking The "commencement of cooling" is defined as the moment when the load current decreases to 80% of the test value, at which point ventilation will be halted.
A.5 Time of the hot resistance measurement and extrapolation of the cooling and heating curves
Resistance measurements of each winding shall commence not later than 45 s after the
“commencement of cooling” and shall be continued for at least 5 min
The time between successive measurements on each winding shall not exceed 20 s during the first 3 min and 30 s thereafter
For large motors that cannot be stopped in time for measurements to begin within 45 seconds, the user and manufacturer must agree on special braking arrangements and an extended time limit of no more than 2 minutes.
The temperature increases derived from the readings will be plotted against time, utilizing a logarithmic scale for temperature and a linear scale for time This curve will then be extrapolated to determine the temperature rise at the point of "commencement of cooling," indicating the final temperature at the conclusion of the test.
Conventional values of traction motor transmission losses
If conventional values of traction motor transmission losses are included in the efficiency calculation they shall be in accordance with figure B.1
Figure B.1 – Conventional values of traction motor transmission losses
Curve a illustrates the loss per stage of reduction for gears with parallel shafts, while Curve b depicts the loss for gears with shafts positioned at right angles Both curves account for the losses associated with suspension or gearbox bearings.
Conventional losses should be utilized for vehicle performance calculations only when specific information is unavailable They should not serve as the sole criteria for accepting or rejecting machines or gearing.
For noise measurement, users must specify that it be conducted on a single machine from the order If a test record from a previously constructed identical machine meets the noise requirements using the methods outlined in this Annex or earlier editions of IEC 60349, it may be accepted Sound pressure level measurements and sound power level calculations must follow Clauses C.5 to C.6, unless alternative methods in C.1 c) are applicable Maximum sound power levels and corrections for pure tones are detailed in Clauses C.7 and C.8 Precision or engineering grade methods, such as ISO 3741, ISO 3743-1, ISO 3743-2, ISO 3744, ISO 3745, ISO 9614-1, or ISO 9614-2, can be used for determining sound power levels when appropriate Alternatively, simpler methods like ISO 3746 or ISO 3747 may be employed, particularly when environmental conditions for ISO 3744 are not met.