---

Table 5 - Minimum immunity requirements for UPS intended for UPS of category C1

CD = contact discharge AD = air discharge AM = amplitude modulation

Power ports with current rating < 100 A: direct coupling using the coupling and decoupling network. Power ports with current rating > 100 A: direct coupling or capacitive clamp without decoupling network. If the capacitive clamp is used, the test level shall be 2 kV/5 kHz.

Light-load test condition is acceptable for power ports rated for current > 63A.

Coupling line to line.

Coupling line to earth.

Applicable only to ports or interfaces with cables whose total length according to the manufacturer's functional specification may exceed 3 m.

The levels in Table 6 shall be applied to UPS, which are intended to be used in the second environment.

Table 6 - Minimum immunity requirements for UPS of category C2 and C3

CD = contact discharge AD = air discharge AM = amplitude modulation

The UPS in operation shall withstand the low-frequency conducted disturbances and signalling in the mains for mains compatibility as specified in IEC 61000-2-2 and as detailed in Annex D (see Clause D.6).

Compliance is checked by simulating the above conditions, and the UPS shall continue to operate without degradation of the specified performances. Criterion: A.

The UPS in operation shall withstand disturbances induced by power-frequency magnetic fields as specified in IEC 61000-4-8: level 2 (10 A/m) for category C1 ; level 3 (30 A/m) for category C2 and C3.

Compliance is checked by simulating the above conditions, and the UPS shall continue to operate without degradation of the specified performances. Criterion: B.

This feature relates to one of the main objectives of a UPS as specified in IEC 62040-3.Annex A

(normative)

Electromagnetic emission -
Test methods

A.1 General

The purpose of these tests is to measure the levels of electromagnetic emission produced by the UPS and propagated by conduction and radiation.

This Annex mainly concerns continuous electromagnetic emissions.

Due to the range of physical size and power ratings, the manufacturer may choose the most appropriate test site and configuration that is best to physically accommodate the UPS.

In some cases, for example, for multi-module systems, the only solution will be a site-installed evaluation. Therefore, the following test set-ups and methods provide, as far as possible, the general criteria to cater for most UPS.

A.2 Measuring equipment

A.2.1 Measuring instruments

Receivers with quasi-peak detectors and with average detectors shall be in accordance with CISPR 16 series of standards.

NOTE Measuring instruments having other detector characteristics may be used provided the measurement of the disturbance values can be proved to be the same. Attention is drawn to the convenience of using a panoramic receiver or a spectrum analyser, particularly if the working frequency of the equipment under test changes appreciably during the work cycle.

A.2.2 Artificial mains network (AMN)

Measurement of the mains terminal disturbance voltage shall be made using an artificial mains network consisting of 50 Q/50 pH network as specified in section 4 of CISPR 16-1-2.

The artificial network is required to provide a defined impedance at radiofrequency across the mains supply at the point of measurement and also to provide for isolation of the equipment under test from ambient noise on the power lines.

A.2.3 Voltage probe

The voltage probe, in accordance with the requirements of Clause 12 of CISPR 16-1-2, and shown in Figure A.1 shall be used where specified for UPS outputs, and when the artificial mains network cannot be used due to the current rating of the input of the UPS. The probe is connected sequentially between each line and the reference earth chosen (metal plate, metal tube).

The probe mainly consists of a blocking capacitor and a resistor so that the total resistance between the line and earth is at least 1 500 Q. The effect on the accuracy of measurement of the capacitor or any other device which may be used to protect the measuring receiver against dangerous currents shall be either less than 1 dB or allowed for in calibration. ¹

The ground connector of the probe is to be connected to reference ground with low impedance. The length of this connection shall be not less than 1/1 Oth of the wavelength of the maximum measurement frequency (>1 m at 30 MHz). In addition, for frequencies below 3 MHz, the length of this connection shall not exceed 10 m.

A.2.4 Antennas

The test shall be carried out in accordance with the requirements of Clause 15 of CISPR 16-1-2.

A.3 Test unit configuration

A.3.1 Where not specified herein, the UPS shall be configured, installed, arranged and operated in a manner consistent with typical applications. Interface cables/loads/devices shall be connected to at least one of each type of interface port of the UPS, and, where practical, each cable shall be terminated in a device typical of actual usage.

Where there are multiple interface ports of the same type, additional interconnecting cables/loads/devices may have to be added to the UPS, depending upon the results of preliminary tests.

The number of additional cables should be limited to the condition in which *he addition of another cable does not affect the emission level by more than 2 dB. The rationale for the selection of the configuration and loading of ports shall be included in the test report.

A.3.2 Interconnecting cables should be of the type and length specified in the individual equipment requirements. If the length can be varied, the length shall be selected to produce maximum emission.

A.3.3 If shielded or special cables are used during the tests to achieve compliance, then a note shall be included in the instruction manual advising of the need to use such cables.

A.3.4 Excess lengths of cables shall be bundled at the approximate centre of the cable, with the bundles 0,3 m to 0,4 m in length. If it is impractical to do so because of cable bulk or stiffness, or because the testing is being made at a user installation, the disposition of the excess cable shall be precisely noted in the test report.

A.3.5 Any set of results shall be accompanied by a complete description of the cable and equipment orientation so that results can be repeated. If there are conditions of use, those conditions shall be specified and documented, for example, cable length, cable type, shielding and grounding. These conditions shall be included in the instruction manual.A.3.6 When equipment which interacts with other equipment to form a system is being evaluated, then the evaluation may be carried out using either additional equipment to represent the total system or with the use of simulators. Using either method, care shall be taken to ensure that the equipment under test is evaluated with the effects of the rest of the system, or simulators satisfying the ambient noise conditions specified in A.6.5. Any simulator used in lieu of an actual device shall properly represent the electrical and, in some cases, the mechanical characteristics of the interface, especially with respect to r.f. signals and impedances as well as cable configuration and types.

NOTE This procedure is required to permit the evaluation of equipment which will be combined with other equipment from different manufacturers to form a system.

A.3.7 For UPS whose battery is external to the unit, the battery shall, where possible, be included in the test set-up and installed in accordance with the manufacturer’s instructions.

Where this is not possible, or the battery including its housing is supplied by others, then this shall be noted in the test report.

A.3.8 AC outputs shall be loaded with resistive devices and be capable of adjustment to obtain the required levels of active power loading for the UPS under test.

A.3.9 The test unit situation relative to the ground plane shall be equivalent to that occurring in use, i.e. a floor-standing UPS is placed on a ground plane or on an isolating floor (for example, wood) close to a ground plane, and a table-top UPS is placed on a non-metallic table. The power and signal cables shall be oriented with respect to the ground plane in a manner equivalent to actual use. The ground plane may be of metal.

NOTE Specific ground plane requirements are given in A.6.3 for terminal voltage measurements and in A.9.1 for field strength measurements.

A.4 Determination of maximum emission configuration(s)

Initial testing shall identify the frequency that has the highest emission relative to the limit while operating the UPS in typical modes of operation and cable positions in a test set-up which is representative of typical system configurations.

The identification of the frequency of the highest emission with respect to the limit shall be found by investigating emissions at a number of significant frequencies as detailed, to give confidence that the probable frequency of maximum emission has been found, and that the associated cable, UPS configurations and mode of operation are identified.

For initial testing, the UPS shall be set up in accordance with Figures A.3 to A.10. The distances between the UPS and peripherals are set according to the figures, and only the cables are to be manipulated in order to find the maximum.

For table-top systems during this process, cables should be manipulated within the range of typical configurations. For floor-standing equipment, the cables should be located in the same manner as the user would install them and no further manipulation has to be made. If the manner of cable installation is not known, or if it changes with each installation, cables for floor-standing equipment shall be manipulated to the extent practical to produce the maximum level of emissions.

Final measurements shall be conducted as in Clauses A.6, A.7 and A.8 for terminal interference voltage and interference field strength measurements, respectively.

A.5 Operation of the equipment under test

The UPS shall be operated at the rated (nominal) operating voltage and typical load conditions for which it is designed. Loads may be actual or simulated. The test programme or other means of exercising UPS should ensure that various parts of the system are exercised in a manner that permits detection of all system emissions, in any mode of operation of the UPS.

A.6 Method of measurement of mains terminal interference voltage

A.6.1 Measuring receivers

Measurements shall be carried out using the quasi-peak and average detector receivers described in A.2.1.

A.6.2 Artificial mains network (AMN)

An artificial mains network as described in A.2.2 shall be used.

Connection of the test unit to the artificial mains network is required, and the test unit is located so that the distance between the boundary of the test unit and the closest surface of the artificial mains network is 0,8 m.

Where a mains flexible cord is provided by the manufacturer, this shall be 1 m long or if in excess of 1 m, the excess cable is folded back and forth as far as possible so as to form a bundle not exceeding 0,4 m in length.

Where a mains cable is specified in the manufacturer's installation instructions, alm length of the type specified shall be connected between the test unit and the artificial mains network.

The test unit shall be arranged and connected with cables terminated in accordance with the manufacturer's instructions.

Earth connections, where required for safety purposes, shall be connected to the reference earth point of the network, and where not otherwise provided or specified by the manufacturer, shall be 1 m long and run parallel to the mains connection at a distance of not more than 0,1 m.

Other earth connections (for example, for EMC purposes), either specified or supplied by the manufacturer for connection to the same ultimate terminal as the safety earth connection, shall also be connected to the reference earth of the network.

It may not be possible to measure at some frequencies because of conducted ambient noise which couples from local broadcast service fields. A suitable additional radiofrequency filter may be inserted between the artificial mains network and the mains supply, or measurements may be performed in a shielded enclosure. The components forming the additional radio­frequency filter should be enclosed in a metallic screen connected direct to the reference earth of the measuring system. The requirements for the impedance of the artificial mains network shall be satisfied, at the frequency of the measurement, with the additional radiofrequency filter connected.

Exception

For UPS whose power rating is beyond the normal ratings of AMNs, it shall be permitted to measure the mains terminal voltage by use of a voltage probe, in accordance with CISPR 16 series of standards, and as shown in Figure A.1.

Where this is done, the mains supply current rating shall be at least the same rating as will be the mains supply of the installed UPS, in order to match as well as possible the site mains source impedance.

A.6.3 Ground plane

The test unit, if unearthed and non-floor-standing, shall be placed 0,4 m from a reference ground plane consisting of a horizontal or vertical metal surface of at least 2 m x 2 m and shall be kept at least 0,8 m from any other metal surface or other ground plane not being part of the test unit. If the measurement is made in a screened enclosure, the distance of 0,4 m may be referred to one of the walls of the enclosure.

Floor-standing test units are subject to the same provisions, with the exception that they shall be placed on a floor, the point(s) of contact being consistent with normal use. The floor may be of metal but shall not make metallic contact with the floor supports of the test unit(s). A metal floor may replace the reference ground plane. The reference ground plane shall extend at least 0,5 m beyond the boundaries of the test unit and have minimum dimensions of 2 m x 2 m.

The reference earth point of the artificial mains network shall be connected to the reference ground plane with a conductor as short as possible, having a length to width ratio of less than 3:1, or be bolted to reference ground-plane.

A.6.4 Equipment set-up for conducted emission measurements

The UPS shall be configured and operated in accordance with the requirements of Clause A.3 and set up in accordance with Figures A.3 to A.8 for table-top equipment and floor-standing equipment.

Table-top UPS shall be placed upon a non-metallic table 0,8 m above the horizontal ground plane (see A.6.3), and 0,4 m from a vertical ground plane which is connected to the horizontal ground plane.

Equipment designed for both table-top or floor operation shall be tested only in the table-top configuration, unless the typical installation is floor-standing, when the respective configuration is used.

Equipment designed for wall-mounted operation shall be tested as table-top UPS. The orientation of the equipment shall be consistent with that of normal operation.

A mains port is connected, via its mains cord, to an AMN, unless being tested in accordance with the exception of A.6.2 at a test site or in situ. An a.c. output port is connected to a load bank. A signal port is connected, via its signal cable, to an impedance stabilisation network (ISN) when intended for connection to an external signal line in practice.А.6.5 Conducted emission measurement

As described in Clause A.4, the one UPS configuration, the one cable configuration and mode of operation which produce the highest emission relative to the limit are found.

Use this configuration to measure and record data. Of those emissions, no greater than 20 dB below the limit, record at least the six highest emission frequencies relative to the limit from the current-carrying mains ports and telecommunications ports of the UPS. The specific conductor for each emission shall be identified.

The emission from a signal port shall, when so specified, be measured as current instead of voltage by means of a current probe, in accordance with section 5 of CISPR 16-1-2.

A.7 Method of measurement at a.c. output ports (where applicable)

The a.c. output port shall be connected to a resistive load bank, and the a.c. output active power shall be increased slowly from zero to the maximum rated value to determine worst-case disturbance voltage.

The load should be purely resistive to avoid errors of measurement with non-sinusoidal waveforms.

The output voltage for which the disturbance is maximum shall be measured by a voltage probe with a characteristic outlined in CISPR 16 series of standards and shown in Figure A.1.

The disturbance voltage shall not exceed the limits of 6.4.2 when measured at the UPS output terminals to the load equipment.

The effect of accuracy of measurement of the voltage probe capacitor or other device which may be used to protect the measuring receiver against dangerous currents shall be either <1 dB or that allowed for in calibration.

The typical connection method is shown in Figure A.5 for connection of the voltage probe. The connection length shall be limited, where practicable, to 2 m in length or additional loss adjustment shall be taken into account.

The probe shall measure each output terminal to reference earth and results recorded.

Where practical, the load shall be positioned 0,8 m from floor-standing UPS or 0,1 m from table-top UPS under test with a load cable length of 1 m.

If the UPS mains input is connected via an artificial mains network (AMN), this shall remain in circuit in order to maintain the defined impedance of the supply.

A.8 Method of measurement of radiated emission

A.8.1 General

Measurements shall be conducted with a quasi-peak detector receiver in the frequency range of 30 MHz to 1 000 MHz.

Measurements of the radiated field shall be made at a distance measured from the boundary of the test unit. The boundary is defined by an imaginary straight line periphery describing a simple geometric configuration encompassing the test unit. All UPS inter-system cables and the UPS shall be included within this boundary.

The specific measurement distances for category C2 UPS and category C1 UPS are given in 6.5.1.

A.8.2 Measuring receivers

The measuring receivers shall be in accordance with the requirements of CISPR 16-1-1.

A.8.3 Antennas

The test shall be carried out in accordance with the requirements of CISPR 16-1-3.

A.9 Measurement site

A.9.1 Test site

The test shall be carried out in accordance with the requirements of CISPR 16-1-5.