IEC 60268-1:1985, Sound system equipment – Part 1: General IEC 60268-3, Sound system equipment – Part 3: Amplifiers IEC 60335-2-2, Household and similar electrical appliances – Safety –
Control methods
According to IEC 60050-161, 161-07-12, asymmetrical controls and half-wave rectification on mains supply are permissible only under specific conditions: a) when they are the sole practical means to detect unsafe conditions, b) when the controlled active input power does not exceed 100 W, or c) when the controlled device is portable, equipped with a two-core flexible cord, and intended for brief use, typically lasting only a few minutes.
If one of these three conditions is fulfilled, half-wave rectification may be used for any purpose, whereas asymmetrical controls may only be used for the control of motors
NOTE 1 Such equipment includes, but is not limited to, hair dryers, electrical kitchen appliances and portable tools
Symmetrical control methods can effectively manage power supplied to heating elements, as long as the full sine-wave input power does not exceed 200 W or the specified limits in Table 3 are maintained These methods may generate low
Symmetrical control methods are permitted for professional equipment if either one of the specified conditions is met, or if the relevant limits are not exceeded at the supply input terminals, along with the fulfillment of both additional conditions.
1) it is necessary to control precisely the temperature of a heater whose thermal time constant is less than 2 s, and
2) there is no other technique economically available
Professional equipment whose primary purpose, considered as a whole, is not for heating, shall be tested against the relevant limits
NOTE 2 An example of a product whose primary purpose is not heating is a photocopier, whereas a cooker is considered to have heating as its primary purpose
Domestic equipment with symmetrical control used for a short time (for example hair dryers) shall be tested under Class A
Even though asymmetrical controls and half-wave rectification are permitted under the conditions given above, the equipment shall still comply with the harmonic requirements of this standard
Asymmetrical controls and half-wave rectification are permitted under specific conditions; however, a fault may cause the d.c component of the supplied current to interfere with certain protection devices This interference can also occur with symmetrical controls.
Harmonic current measurement
Test configuration
Specific test conditions for the measurement of harmonic currents associated with some types of equipment are given in Annex C
For equipment not listed in Annex C, emission tests must be performed with the user's operational controls or automatic programs configured to the mode likely to generate the highest total harmonic current (THC) during standard operating conditions This specifies the equipment setup for emission testing, rather than imposing a requirement to measure THC or to seek out worst-case emissions.
The harmonic current limits outlined in Clause 7 pertain specifically to line currents, excluding those in the neutral conductor However, for single-phase equipment, it is acceptable to measure the currents in the neutral conductor as an alternative to measuring the line currents.
The equipment undergoes testing based on the manufacturer's guidelines and information Prior to testing, the manufacturer may need to conduct preliminary operations on the motor drives to ensure that the results align with standard usage.
Measurement procedure
The test shall be conducted according to the general requirements given in 6.2.3 The test duration shall be as defined in 6.2.4
The measurement of harmonic currents shall be performed as follows:
– for each harmonic order, measure the 1,5 s smoothed r.m.s harmonic current in each DFT time window as defined in Annex B;
– calculate the arithmetic average of the measured values from the DFT time windows, over the entire observation period as defined in 6.2.4
The value of the input power to be used for the calculation of limits shall be determined as follows:
– measure the 1,5 s smoothed active input power in each DFT time window;
– determine the maximum of the measured values of power from the DFT time windows over the entire duration of the test
NOTE The active input power supplied to the smoothing section of the measuring instrument as defined in Annex B is the active input power in each DFT time window
The harmonic currents and the active input power shall be measured under the same test conditions but need not be measured simultaneously
To avoid confusion regarding limit changes, manufacturers can specify a power value within ±10% of the actual measured value for conformity assessment tests Both the measured and specified power values must be documented in the test report.
During emission tests, if the measured power value falls between 90% and 110% of the manufacturer's specified power value in the test report, this specified value will be used to set the limits However, if the measured value is outside this tolerance range, the actual measured power will be used to establish the limits.
For Class C equipment, the manufacturer-specified fundamental current and power factor must be utilized for limit calculations Both the fundamental current component and power factor are measured similarly to how power is assessed for Class D limits The power factor value should be derived from the same DFT measurement window used for the fundamental current component.
General requirements
The average value of individual harmonic currents must demonstrate a repeatability of better than ±5% of the applicable limit throughout the entire test observation period, provided that specific conditions are satisfied.
– the same equipment under test (EUT) (not another of the same type, however similar); – identical test conditions;
– identical climatic conditions, if relevant
NOTE This repeatability requirement serves the purpose of defining the necessary observation period, see 6.2.4
It is not intended to serve as a pass/fail criterion for the assessment of compliance with the requirements of this standard
The reproducibility of measurements on the same Equipment Under Test (EUT) using different test systems cannot be precisely determined for all combinations of EUT, harmonics meter, and test supply However, it can be estimated to be better than ± (1 % + 10 mA), where 1 % refers to the average total input current over the entire test observation period Consequently, differences in results below this current threshold are considered negligible, although higher discrepancies may occasionally arise.
To clarify, test results from various locations or occasions that meet all relevant limits will be accepted as proof of compliance, even if the results differ beyond the specified values for repeatability and reproducibility.
Variability in measurements across different Equipment Under Test (EUT) of the same type, which are not intentionally different, can be influenced by practical component tolerances and interactions between the EUT's characteristics and the measuring instrument or power supply This standard does not quantify the effects of these interactions due to similar reasons as those affecting reproducibility Additionally, the considerations outlined in the second paragraph of section 6.2.3.2 are relevant to this variability.
A regulatory concession in respect of limit values to allow for possible variability is recommended but outside the scope of this standard
When equipment is switched on or off, either manually or automatically, harmonic currents and power are disregarded for the initial 10 seconds after the operation change.
The equipment under test shall not be in stand-by mode (see 3.18) for more than 10 % of any observation period
The average values for the individual harmonic currents, taken over the entire test observation period shall be less than or equal to the applicable limits
For each harmonic order, the 1.5 s smoothed r.m.s harmonic current values must meet specific criteria: they should either be less than or equal to 150% of the applicable limits, or less than or equal to 200% of the applicable limits, provided that certain conditions are simultaneously met.
1) the EUT belongs to Class A for harmonics;
2) the excursion beyond 150 % of the applicable limits lasts less than 10 % of the test observation period or in total 10 min (within the test observation period), whichever is smaller, and
3) the average value of the harmonic current, taken over the entire test observation period, is less than 90 % of the applicable limits
Harmonic currents less than 0,6 % of the input current measured under the test conditions, or less than 5 mA, whichever is greater, are disregarded
For the 21st and higher odd order harmonics, the average value for each individual odd harmonic, calculated from the 1.5 s smoothed r.m.s values, may exceed the applicable limits by 50% if specific conditions are satisfied.
• the measured partial odd harmonic current does not exceed the partial odd harmonic current which can be calculated from the applicable limits;
• all 1,5 s smoothed r.m.s individual harmonic current values shall be less than or equal to
The exemptions regarding the use of partial odd harmonic current for average values and the 200% short-term limit for single 1.5-second smoothed values are mutually exclusive and cannot be applied simultaneously.
The test report can originate from data provided by the manufacturer to a testing facility or document the manufacturer's own testing results It must encompass all pertinent information regarding the test conditions, the duration of observations, and, if necessary for determining limits, the active power, fundamental current, and power factor.
Test observation period
Observation periods (T obs ) for four different types of equipment behaviour are considered and described in Table 4.
Equipment in a rack or case
When equipment is installed in a rack or case, each item is considered to be independently connected to the mains supply, meaning the entire rack or case does not require testing as a single unit.
The procedure for applying the limits and assessing the results is shown in Figure 1
For the following categories of equipment, limits are not specified in this standard:
NOTE 1 Limits may be defined in a future amendment or revision of the standard
– equipment with a rated power of 75 W or less, other than lighting equipment;
NOTE 2 This value may be reduced from 75 W to 50 W in the future, subject to approval by National Committees at that time
– professional equipment with a total rated power greater than 1 kW;
– symmetrically controlled heating elements with a rated power less than or equal to 200 W; – independent dimmers for incandescent lamps with a rated power less than or equal to
Start here: determine class (Clause 5)
Uses techniques not allowed by 6.1 ?
Belongs to exceptions of Clause 7 or Annex C
Test conditions defined in Clause C.2 and onwards ?
Use the ˝generic˝ conditions in 6.2.1 Apply those conditions
Figure 1 – Flowchart for determining conformity
NOTE I p(abs) is the higher absolute value of I p+ and I p-
Figure 2 – Illustration of the relative phase angle and current parameters described in 7.3 b)
Limits for Class A equipment
For Class A equipment, the harmonics of the input current shall not exceed the values given in Table 1
Audio amplifiers shall be tested according to Clause C.3 Dimmers for incandescent lamps shall be tested according to Clause C.6.
Limits for Class B equipment
For Class B equipment, the harmonics of the input current shall not exceed the values given in Table 1 multiplied by a factor of 1,5.
Limits for Class C equipment
For lighting equipment having an active input power greater than 25 W, the harmonic currents shall not exceed the relative limits given in Table 2
However, the limits given in Table 1 apply to incandescent lighting equipment that has built- in dimmers or consists of dimmers built in an enclosure
For discharge lighting equipment that has built-in dimmers or consists of independent dimmers or dimmers built in an enclosure, the following conditions apply:
– the harmonic current values for the maximum load condition derived from the percentage limits given in Table 2 shall not be exceeded;
– in any dimming position, the harmonic current shall not exceed the value of current allowed in the maximum load condition;
– the equipment shall be tested according to the conditions given in Clause C.5 (see the last paragraph of C.5.3) b) Active input power ≤ 25 W
Discharge lighting equipment having an active input power smaller than or equal to 25 W shall comply with one of the following two sets of requirements:
Harmonic currents must adhere to the power-related limits specified in Table 3, column 2 Specifically, the third harmonic current should not exceed 86% of the fundamental current, while the fifth harmonic current must remain below 61% Additionally, the input current waveform must reach the 5% current threshold by or at 60°, achieve its peak value by or at 65°, and not drop below the 5% current threshold before 90°, relative to any zero crossing of the fundamental supply voltage The 5% current threshold is defined as 5% of the highest absolute peak value within the measurement window, with phase angle measurements taken during the cycle that includes this peak value.
If the discharge lighting equipment has a built-in dimming device, measurement is made only in the full load condition.
Limits for Class D equipment
For Class D equipment, it is essential to measure harmonic currents and power as outlined in section 6.2.2 The input currents at harmonic frequencies must remain within the limits specified in Table 3, in accordance with the requirements detailed in sections 6.2.3 and 6.2.4.
Table 1 – Limits for Class A equipment
Table 2 – Limits for Class C equipment
Harmonic order Maximum permissible harmonic currrent expressed as a percentage of the input current at the fundamental frequency n %
(odd harmonics only) 3 a λ is the circuit power factor
Table 3 – Limits for Class D equipment
Harmonic order Maximum permissible harmonic current per watt
Maximum permissible harmonic current n mA/W A
Type of equipment behaviour Observation period
To ensure repeatability as outlined in section 6.2.3.1, quasi-stationary observations (T obs) must be of sufficient duration For short cyclic observations (T cycle ≤ 2.5 min), a minimum of 10 cycles is required, or the observation must be long enough or synchronized to meet the repeatability criteria Random observations also need to be of adequate duration to fulfill the repeatability requirements In the case of long cyclic observations (T cycle > 2.5 min), a full equipment program cycle or a representative 2.5-minute period deemed by the manufacturer as the peak operating period for THC is necessary Synchronization refers to ensuring that the total observation period closely aligns with an exact integral number of equipment cycles to satisfy the repeatability standards.
Measurement circuit and supply source
Test circuit
The harmonic values obtained will be compared to the limits specified in Clause 7 The harmonic currents of the equipment under test (EUT) must be measured according to the circuits illustrated in the subsequent figures.
– Figure A.1 for single-phase equipment;
– Figure A.2 for three-phase equipment
Measurement equipment complying with Annex B shall be used Test conditions for the EUT are given in Annex C.
Supply source
During testing, the voltage (U) at the equipment's terminals must adhere to specific requirements outlined in Annex C Firstly, the test voltage should equal the equipment's rated voltage, set at 230 V for single-phase and 400 V for three-phase supplies, with a tolerance of ±2.0% for voltage and ±0.5% for frequency Additionally, for three-phase supplies, the phase angle between the fundamental voltages of each pair must be maintained at 120° ± 1.5° Lastly, the harmonic ratios of the test voltage must not exceed specified limits when the equipment under test (EUT) is connected as it would be during normal operation.
0,2 % for even harmonics of order from 2 to 10;
Harmonics of order 11 to 40 should be limited to 0.1% The peak value of the test voltage must be between 1.40 and 1.42 times its RMS value, achieved within 87° to 93° after the zero crossing This specification is not applicable for testing Class A or B equipment.
S power supply source Z M input impedance of measurement equipment
M measurement equipment Z S internal impedance of the supply source
EUT equipment under test I n harmonic component of order n of the line current
U test voltage G open-loop voltage of the supply source
Z S and Z M values are unspecified but must be low enough to meet the requirements of Clause A.2 This is verified by measuring the supply voltage properties at the connection point of the Equipment Under Test (EUT) to the measurement equipment, as detailed in IEC 61000-4-7.
NOTE 2 In some special cases, particular care may be necessary to avoid resonance between the internal inductance of the source and the capacitances of the equipment under test
For certain equipment types, like single-phase uncontrolled rectifiers, harmonic amplitudes can significantly fluctuate with supply voltage To reduce this variability, it is advisable to keep the voltage at the connection point of the Equipment Under Test (EUT) to the measurement equipment at 230 V or 400 V, with a tolerance of ±1.0 V, assessed over the same conditions.
200 ms observation window, used for harmonic assessment
Figure A.1 – Measurement circuit for single-phase equipment
G open-loop voltage of the supply source
Z M input impedance of the measurement equipment
Z S internal impedance of the supply source
I n harmonic component of order of the line current
U test voltage (shown as an example between phases L1 and L2)
Z S and Z M values are unspecified but must remain sufficiently low to meet the requirements outlined in Clause A.2 Compliance is verified by measuring the supply voltage properties at the connection point of the Equipment Under Test (EUT) to the measurement equipment, as detailed in IEC 61000-4-7.
NOTE 2 In some special cases, particular care may be necessary to avoid resonance between the internal inductance of the source and the capacitances of the equipment under test
For certain equipment types, like single-phase uncontrolled rectifiers, harmonic amplitudes can significantly fluctuate with supply voltage To reduce this variability, it is advisable to keep the voltage at the connection point of the Equipment Under Test (EUT) to the measurement equipment at 230 V or 400 V, with a tolerance of ±1.0 V, assessed over the same period.
200 ms observation window, used for harmonic assessment
Figure A.2 – Measurement circuit for three-phase equipment
The requirements for measurement equipment are defined in IEC 61000-4-7
General
The test conditions for the measurement of harmonic currents associated with some types of equipment are given in the following clauses
NOTE Product committees are invited to submit proposals for defined test conditions for specific products to IEC SC 77A, for inclusion in this Annex.
Test conditions for television (TV) receivers
General conditions
Measurements shall include the loading of any auxiliary circuits included in the receiver, but exclude the loading of any peripheral equipment powered from the receiver.
Conditions for measurement
A test generator will provide a radio-frequency signal modulated as per C.2.2.1, while the receiver must be calibrated to show a picture with the correct brightness, contrast, and sound level according to C.2.2.2.
C.2.2.1 The TV receiver is fed by an r.f TV input signal with a level of 65 dB(àV) across
75 Ω and with the following test modulations a) Color television
Radio-frequency signal: a full TV signal with modulated picture chrominance and sound carrier:
– the sound modulation factor is 54 % at 1 000 Hz;
– the picture modulation content is a color bar test pattern according to Recommendation ITU-R BT.471-1:
• 75 % amplitude (reference made to the white level); and
Radio-frequency signal: a full TV signal with modulated picture and sound carrier:
– sound modulation: see item a) above;
– the picture modulation is a monochrome test pattern with a black and white level according to item a) and an average overall picture content of 50 % of the reference white level
C.2.2.2 The receiver shall be tuned according to IEC 60107-1
The white reference level corresponds to 80 cd/m2 and the black level to less than 2 cd/m 2 The magenta bar corresponds to 30 cd/m 2
The volume control is adjusted to achieve one-eighth of the rated output power, measured at the loudspeaker terminals at a frequency of 1,000 Hz For stereophonic equipment, this output must be available at both channels.
NOTE For devices that operate on base-band signals, suitable video and audio input signals should be used, and the same settings made for brightness, contrast and volume controls.
Test conditions for audio amplifiers
Conditions
Audio amplifiers that draw a supply current varying by less than 15% of the maximum current, with input signal voltages ranging from zero to the rated source e.m.f as defined in IEC 60268-3, must be tested without an input signal.
Other audio amplifiers shall be tested under the following conditions:
• normal position of user controls In particular, any controls affecting the frequency response set to give the widest flat response achievable;
• input signals and loads as given in C.3.2.
Input signals and loads
To conduct the test procedure, connect appropriate resistors that match the rated load impedance to each amplifier output for loudspeaker operation To observe the output voltage waveform of the audio amplifier in a powered loudspeaker, link the audio analyzer or oscilloscope to the internal wiring at a point that reflects the amplifier's electrical output.
NOTE 1 In the case of powered loudspeakers with internal audio amplifiers, the load is the loudspeaker and associated crossover network b) Apply a sinusoidal signal at 1 kHz (see Note 2) to a suitable input For multi-channel amplifiers in which the surround sound channel amplifiers cannot be alternatively used as a second set of left and right channel amplifiers, set the controls so that the surround sound channel amplifiers are supplied with signal at a level 3 dB lower than the signal applied to the left and right channels
NOTE 2 For products not intended to reproduce 1 kHz signals, a frequency geometrically centred within the reproducing bandwidth of the amplifier is applied c) Adjust the input signal and/or amplifier gain control(s) so as to obtain an output signal for the left and right channels having 1 % total harmonic distortion, simultaneously If 1 % total harmonic distortion cannot be obtained, adjust the signal voltage and/or gain controls to obtain the highest achievable power output at each output simultaneously Confirm that the output signals of the surround sound channel amplifiers are 3 dB lower than the output signal at the outputs of the left and right channels d) Measure the output voltages of all channels and then readjust the input signal voltage and/or controls to obtain voltages of 0,354 (1/√8) times the voltages obtained at the end of step c) above e) In the case of products with provision for connection to external loudspeakers, proceed as specified in 6.2 f) For products with internal loudspeakers and without provision for connection to external loudspeakers, note the r.m.s output voltage of the sinusoidal signal at the output of each amplifier Substitute the sinusoidal signal by a pink noise signal, bandwidth-limited as specified in 6.1 of IEC 60268-1 Confirm the r.m.s value of the pink noise signal as it appears at the output of each amplifier output is equal to the r.m.s value of the sinusoidal waveform for that channel set as in step d) above Proceed as specified in 6.2.
Test conditions for video-cassette recorders
Measurements shall be made in the playback mode with the standard tape speed.
Test conditions for lighting equipment
General conditions
Measurements shall be made in a draught-free atmosphere and at an ambient temperature within the range from 20 °C to 27 °C During measurement the temperature shall not vary by more than 1 K.
Lamps
Discharge lamps must be aged for a minimum of 100 hours at their rated voltage and operated for at least 15 minutes prior to taking measurements Certain lamp types may need a stabilization period longer than 15 minutes It is essential to adhere to the guidelines specified in the relevant IEC lamp performance standards.
During ageing, stabilization and measurement, lamps shall be installed as in normal use Self- ballasted lamps shall be operated in cap-up position.
Luminaires
The luminaire is tested using reference lamps or lamps with electrical characteristics close to their nominal values In uncertain cases, reference lamps are utilized for measurements For luminaires with multiple lamps, all lamps must be connected and operated during testing If a luminaire is designed for various lamp types, measurements must be conducted with each type, ensuring compliance each time Additionally, if the luminaire features a glow starter, it must use a starter that meets IEC 60155 standards.
Incandescent lamp luminaires which do not incorporate an electronic transformer or a dimming device are deemed to fulfil the harmonic current requirements and need not be tested
If individual tests with reference lamps confirm that ballasts for fluorescent or discharge lamps, as well as step-down converters for tungsten halogen or filament lamps, meet the necessary requirements, the luminaire is considered compliant and does not require further testing However, if these components have not been separately approved or do not meet the standards, the luminaire must undergo testing to ensure compliance.
When a luminaire features an integrated dimming device, harmonic currents must be assessed at the lamps' maximum load as indicated by the manufacturer To ensure thorough results, the dimming device is adjusted in five equal increments between its minimum and maximum power settings.
Ballasts and step-down converters
Ballast for fluorescent and discharge lamps, as well as step-down converters for tungsten halogen or filament lamps, must be tested using reference lamps or lamps with electrical characteristics similar to their nominal values If there is any uncertainty, testing should be conducted with reference lamps.
When a ballast is applicable, whether used alone or with a series capacitor, or when designed for multiple lamp types, the manufacturer must specify in their catalog the circuit types and lamps for which the ballast meets harmonic requirements, and it must be tested accordingly.
Test conditions for independent and built-in incandescent lamp dimmers
The dimmer is evaluated using incandescent lamps at the maximum power capacity permitted The control is adjusted to a firing angle of 90° ± 5°, or to the nearest step if the control operates in increments.
Test conditions for vacuum cleaners
The air inlet of the vacuum cleaner is adjusted according to normal operation as defined in IEC 60335-2-2
Vacuum cleaners with electronic control shall be tested in three modes of operation, each for an identical time interval that is at least 2 min long, with the control adjusted:
– to 50 % ± 5 % of the maximum active input power, or, if that is not possible (e.g controlled in steps), to the point closest to 50 % that is supported by the equipment design,
– and to minimum input power
The three time intervals do not have to be consecutive; however, limits are applied as if they were Consequently, the entire test observation period consists of these three identical intervals, disregarding any harmonic current values outside of them.
When a vacuum cleaner features a temporary high-power ('booster') mode that automatically reverts to a lower power setting, this mode is excluded from the average value calculations Instead, it should be evaluated solely against the limits for single 1.5-second smoothed root mean square (r.m.s.) values as specified in section 6.2.3.4.
Test conditions for washing machines
The washing machine must undergo testing using a full laundry program that includes the normal wash cycle, utilizing a rated load of double hemmed, pre-washed cotton cloths measuring approximately 70 cm × 70 cm, with a dry weight ranging from 140 g/m² to 175 g/m².
The temperature of the fill water shall be
• 65 °C ± 5 °C for washing machines without heating elements and intended for connection to a hot water supply;
• from 10 °C to 25 °C for other washing machines
For washing machines equipped with a programmer, utilize the 60 °C cotton program without pre-wash when available; if not, opt for the standard wash program without pre-wash In cases where the washing machine has heating elements not regulated by the programmer, ensure the water is heated to 65 °C ± 5 °C prior to commencing the first wash cycle.
For washing machines equipped with heating elements but lacking a programmer, it is essential to heat the water to a temperature of 90 °C ± 5 °C, or lower if stable conditions are achieved, prior to initiating the first wash cycle.
Test conditions for microwave ovens
The microwave oven is evaluated at full nominal power using a potable water load of 1,000 g ± 50 g, contained in a cylindrical borosilicate glass vessel with a maximum material thickness of 3 mm and an outside diameter of about 190 mm The water load is positioned at the center of the shelf for optimal testing.
Test conditions for information technology equipment (ITE)
General conditions
ITE products, including personal computers, are tested in their supplied state when marketed without factory-fitted options or expansion slot capabilities In contrast, ITE devices other than personal computers that come with factory-fitted options or have expansion slots are evaluated with additional loads in each slot, ensuring maximum power consumption based on the manufacturer's specified options.
For testing personal computers with up to 3 expansion slots, load cards must be added to each slot, configured for the maximum allowed power For systems with more than 3 expansion slots, at least one additional load card should be installed for every group of up to 3 extra slots, ensuring a minimum of 4 load cards for configurations with 4 to 6 slots.
8 or 9 slots a total of at least 5 load cards shall be added, etc.)
Modular equipment, such as hard drive arrays and network servers, are tested in their maximum configuration
In all configurations, the use of additional load cards shall not cause the total DC output power available to be exceeded
NOTE 1 The above does not mean that multiple options of the same type, such as more than one hard drive, should be fitted, unless that is representative of the user configuration, or the product is of a type (such as Redundant Arrays of Inexpensive Disks (RAID)) for which such a configuration is not abnormal
NOTE 2 Common load cards for expansion slots such as PCI or PCI-2 are configured for 30 W but may be adjusted as industry standards change
Emission tests must be performed with the user's operation controls or automatic programs configured to the mode that is anticipated to generate the highest total harmonic current (THC) during standard operating conditions.
Power saving modes which may cause large power level fluctuations shall be disabled, so that all, or part, of the equipment does not automatically switch off during the measurements
ITE systems that utilize a manufacturer-supplied power distribution system, including transformers, UPS, or power conditioners, must adhere to the compliance limits set by this standard for the input sourced from the public low-voltage distribution network.
C.10.2 Optional conditions for measuring emissions of IT equipment with external power supplies or battery chargers
For IT equipment with external power supplies or battery chargers, manufacturers may choose
• either to test the whole equipment according to C.10.1 (General conditions),
To evaluate the equipment, measure the AC input power and harmonic emissions of the power supply or battery charger as specified in section 6.2.2 Ensure that the DC output side is loaded with a resistive load, and verify that the peak-to-peak ripple voltage across the load does not exceed 5% of the DC output voltage.
The load resistance must be set to ensure that the active power dissipated matches the DC output power rating If the power rating is unavailable, it should equal the product of the DC output voltage and the DC output current ratings specified on the power supply or battery charger.
Power supply and battery charger units with an AC input power of 75 W or less, measured under the conditions specified in section 6.2.2, are considered compliant without the need for additional testing, as outlined in Clause 7.
Test conditions for induction hobs
Induction hobs require an enamelled steel pan filled with about half its capacity of room temperature water, placed at the center of each cooking zone The thermal controls should be set to their maximum level for optimal operation.
The pan's base diameter must be at least equal to the cooking zone's diameter, with the smallest compliant pan being utilized Additionally, the maximum allowable concavity of the pan's base is defined as 3D/1,000, where D represents the diameter of the flat area of the base It is also essential that the base of the pan remains flat and not convex.
The concavity is checked at room temperature using an empty pan.
Test conditions for air conditioners
Controlling the input power of an air conditioner with an electronic device allows for adjustments in the fan or compressor motor speed to achieve the desired air temperature Harmonic currents are then measured once the system reaches a steady-state operation.
– The temperature control shall be set to the lowest value in the cooling mode and to the highest value in the heating mode
– The ambient temperature for testing shall be 30 °C ± 2 °C in the cooling mode, and
In heating mode, the air conditioner operates optimally at a temperature of 15 °C ± 2 °C If the rated input power is achieved at a higher temperature, testing will occur at that ambient temperature, provided it does not exceed 18 °C The ambient temperature refers to the air temperature drawn from both the indoor and outdoor units of the appliance.
When heat is transferred to a medium such as water instead of the surrounding air, it is essential to select all settings and temperatures to ensure the appliance operates at its rated input power.
If the air conditioner does not contain power electronic elements (e.g diodes, dimmers, thyristors, etc.), it need not be tested against harmonic current limits.
Test conditions for kitchen machines as defined in IEC 60335-2-14
Kitchen machines as listed in the scope of IEC 60335-2-14 are deemed to conform to the harmonic current limits of this standard without further testing.
Test conditions for arc welding equipment which is not professional
Testing must occur at ambient temperatures ranging from 20 °C to 30 °C, starting with the arc welding power source at the same temperature The power source should be connected to a conventional load and operated at the rated maximum welding current, I 2max, along with the conventional load voltage specified in Table C.1 The observation period will consist of either 10 thermal cycles for short cyclic equipment (where the first thermal cycle is 2.5 minutes or less) or one full thermal cycle for long cyclic equipment (where the first thermal cycle exceeds 2.5 minutes) For multi-process arc welding power sources, testing should utilize the process that results in the highest input current.
I 2 and U 2 are given in IEC 60974-1
Table C.1 – Conventional load for arc welding equipment tests
V Manual metal arc welding with covered electrodes U 2 = (18 + 0,04 I 2 )
Metal inert/active gas and flux cored arc welding U 2 = (14 + 0,05 I 2 )
Test conditions for high pressure cleaners which are not professional
The high pressure cleaner is adjusted according to normal operation as defined in IEC 60335-2-79 except for the electronic power control
High pressure cleaners equipped with electronic power control must undergo testing in three operational modes, with each mode being evaluated for a minimum duration of 2 minutes, while the control settings are adjusted accordingly.
– to 50 % ± 5 % of the maximum active input power, or, if that is not possible (e.g controlled in steps), to the point closest to 50 % that is supported by the equipment design,
– and to minimum input power
The three time intervals do not have to be consecutive; however, limits are applied as if they were Consequently, the entire test observation period consists of these three identical intervals, disregarding any harmonic current values outside of them.
Test conditions for refrigerators and freezers
General
Refrigerators and freezers must be tested while empty, with the temperature control set to the lowest setting Measurements should commence only after the internal temperature has stabilized.
NOTE Stabilisation of the temperature can alternatively be deduced, for example, from the input power going into a low power mode
When the measurement is started, the ambient temperature shall be between 20 °C and 30 °C During the test the ambient temperature shall be maintained within ±2 °C.
Refrigerators and freezers with VSD
The observation period lasts for one hour Shortly after the measurement begins, all doors and internal compartments will be fully opened for 60 seconds before being closed and kept shut for the remainder of the observation period.
NOTE 1 A timing accuracy of ± 6 s is deemed to be sufficient for the targeted measurement repeatability, see Note 3 below
Deviating from 6.2.2, the value of the input power to be used for the calculation of limits shall be determined according to the formula below:
P i is the active input power in watts, to be used for the calculation of Class D limits (see Table 3);
I m is the current in amperes of the appliance measured according to IEC 60335-2-24, 10.2;
U r is the rated voltage in volts of the appliance If the appliance has a rated voltage range, U r has the value that has been used for measuring I m
NOTE 2 P i is used for the calculation of limits instead of the measured active input power to eliminate the influence of other loads than the VSD, e.g lighting devices or heating elements for defrosting, on the limit calculation This also increases the repeatability of the measurement
NOTE 3 The 5 % repeatability, mentioned in 6.2.3.1, can be achieved only if the climatic conditions are strongly controlled and, for each test, the measurement is started at the same point in the control cycle of the EUT If these conditions are not fulfilled, the repeatability of the average value of the individual harmonic currents over the entire test observation period can be as much as 10 % of the applicable limit.
Refrigerators and freezers without VSD
Refrigerators and freezers lacking variable speed drives for compressor motor control are evaluated based on Class A limits during a representative observation period of 2.5 minutes, as outlined in Table 4 for long cyclic equipment.
IEC 60974-6, Arc welding equipment – Part 6: Limited duty equipment