Conducted Immunity

Basic- and Product standard requirements & Solutions


Testing Immunity to Conducted Transients

Ever since the field of “Electromagnetic Compatibility” (EMC) became mainstream, its principles and methods are applied in order to ensure that electric and electronic equipment is performing as intended in its environment and is safe to use. Initially carried out for quality purposes, the EMC tests and measurements have basically become an essential precondition for marketing any product that contains electric/electronic components. For the purpose of this description, an EQUIPMENT UNDER TEST (EUT) exchanges energy with its ENVIRONMENT through different PORTS, as described in the simplified diagram below.

 

 

imu app img1The examples provided are only a few of the ports that might be mentioned in product standards. Unsymmetrical ports refer to the ports handling unsymmetrical signals (for example ports with neutral and active conductors) whereas symmetrical ports handle symmetrical signals transmitted over pairs of conductors (Ethernet signals, USB D+ and D-, RS 485 TX- and TX- or RX- and RX-, etc.).

 

 

 

What is conducted and radiated emission?

Electric, magnetic or electromagnetic energy produced and usually unintentionally transferred by the EUT to its environment is referred to as emission in the EMC context. Unintentional electric, magnetic or electromagnetic energy that propagates from the EUT to environment or inversely is also mentioned as disturbance.

Radiated emission is generally transferred to the environment through the Enclosure port, but the cables attached to EUT’s ports can also act as unintentional antennas and radiate energy. The radiated emission is limited through different regulations and technical standards, while its measurement takes place is controlled environments like anechoic chambers or Open Area Test Sites (OATs).

Conducted emission represents the energy transferred unintentionally from EUT to the environment through the conductors attached to its ports. In this case, the power source/network and other Auxiliary Equipment (AE) are considered part of the environment. An example of conducted emissions measurement is provided in the standard IEC 61000-3-2, which specifies limits for current harmonics at an EUT’s power supply support under certain reproducible conditions. Such measurements can be performed with test systems like HAR-1000.

What is conducted and radiated immunity?

The ability of an EUT to function as intended in its environment, in which conducted and radiated disturbances may exist, is considered a satisfactory EMC immunity.

Unintentional electric, magnetic or electromagnetic fields that are incident to EUT Enclosure port, or induce voltages and/or currents in the conductors connected to EUT ports are considered radiated disturbances. Likewise, unintentional voltages and currents present on the conductors connected to EUT ports are considered conducted disturbances. The ability of an EUT to withstand both types of disturbance is considered conducted and radiated immunity.

Establishing the immunity of an EUT implies simulation of disturbances expected in its intended environment. Similar to radiated emission measurement, radiated immunity tests are performed usually in controlled environments.

The assessment of EUT’s conducted immunity may or may not require special test setups or environments, depending on the type of disturbance. The simulation of conducted disturbances, with the purpose of establishing an EUT’s immunity level, encompasses a broad range of applications and is described in standards applicable to more markets. As subcategories, one could mention immunity to conducted low frequency or high frequency swept disturbances, narrowband or broadband disturbances, immunity to impulse disturbances (sometimes called transients), short-term or long-term, repetitive, disturbances, etc. Technical requirements for conducted immunity assessment of household or industrial equipment are generally associated with International Electrotechnical Commission (IEC) standards, whereas other type of equipment is assessed according to other standards: military equipment generally according to MIL series of standards or similar, avionics equipment according to RTCA DO-160 or manufacturer standards, telecom equipment according to International Telecommunication Union (ITU) standards or similar, to name just a few. In the following section, a part of IEC immunity requirements for household and industrial equipment will be introduced, with particular focus on immunity to impulse disturbances, or transients.

The IEC 61000-4-X series of standards describes requirements for immunity tests on a broad range of EUTs, generally connected to a power grid. The phenomena described in the IEC 61000-4-X series is representative for the environments mentioned above. Full-compliance testing implies the use of disturbance generators and accessories that allow the precise reproduction of signal within tolerances specified by the standard, as well as following the prescribed calibration and testing steps in an environment that also respects standard requirements. While in other fields “pre-compliance” testing for development purposes would have the potential to deliver some insights, immunity to conducted disturbances and particularly impulse tests might generally require a full-compliance test system in order to obtain meaningful results.

Electrical Fast Transients (EFT) or Burst is a disturbance occurring in low-voltage networks when connecting or disconnecting inductive loads. Even if an EUT did not contain inductive components, a longer power cord already introduces inductance in the circuit. Hence, the occurrence of burst phenomenon is relatively high and all equipment connected to the power grid requires an immunity test. Standardized high-voltage bursts (trains of impulses) can be generated and coupled to the power lines by means of a coupling/decoupling network (CDN) on power lines. The IMU Series of generators from EMC PARTNER generate full-compliant burst signals up to 4 kV, 5 kV, 6 kV or 7 kV depending on the model and suitable coupling/decoupling networks for power lines, as required in latest edition of IEC 61000-4-4. Coupling on communication, control, auxiliary lines can be performed by a means of a capacitive coupling clamp, like the CN-EFT1000.

Requirements for surge immunity tests are specified in IEC 61000-4-5 (up to 4 kV) or ANSI/IEEE C62.41 and ANSI C62.45 (up to 6 kV). Along burst phenomenon, surge constitutes a disturbance that can occur very often in the supply grid, due to switching, resonances associated with switching, faults, and eventually reach other types of ports than power supply ports, since surges can also be produced by lighting strokes.

The series of phenomena and test requirements associated with voltage dips, short interruptions and voltage variations on AC lines are described in IEC 61000-4-11 and IEC 61000-4-34. Due to the relatively fast switch time and high inrush currents that appear during these disturbances, EUTs may be subjected to considerable stress. The IMU generators and suitable accessories can be utilized to successfully assess immunity to voltage dips, short interruptions and voltage variations.

A special test considered closely related to/part of conducted immunity tests is Electrostatic Discharge (ESD). In IEC 61000-4-2, test requirements and levels defined are meant to ensure an EUT’s immunity to ESD phenomenon produced by an electrically charged human body when touching it (i.e. the EUT). Such disturbances can be generated with IMU generators and suitable accessories (EXT-IMU E primarily), but also with the dedicated ESD3000.

The IMU series of transient generators, along with suitable accessories, are multipurpose full-compliance test systems, allowing immunity tests according but not limited to the standards mentioned above. Among other capabilities, the IMU series of generators can be utilised for following additional conducted immunity tests:

  • Ring wave according to IEC 61000-4-12 and ANSI/IEEE C62.41
  • Common mode disturbance according to IEC 61000-4-16
  • Differential mode disturbance according to IEC 61000-4-19.

Immunity tests to Damped Oscillatory Waves according to IEC 61000-4-18 can be carried out with the generator DOW-CG1 and suitable accessories.

IEC 61000-4-2

Electromagnetic compatibility (EMC) - Part 4-2: Testing and measurement techniques - Electrostatic discharge immunity test

IEC 61000-4-4

Electromagnetic compatibility (EMC) - Part 4-4: Testing and measurement techniques

IEC 61000-4-5

Electromagnetic compatibility (EMC) - Part 4-5: Testing and measurement techniques - Surge immunity test

IEC 61000-4-8

Electromagnetic compatibility (EMC)

IEC 61000-4-9

Electromagnetic compatibility (EMC) - Part 4-9: Testing and measurement techniques - Impulse magnetic field immunity test

IEC 61000-4-10

Electromagnetic compatibility (EMC) - Part 4-10: Testing and measurement techniques - Damped oscillatory magnetic field immunity test

IEC 61000-4-11

Electromagnetic compatibility (EMC) - Part 4-11: Testing and measurement techniques - Voltage dips, short interruptions and voltage variations immunity tests

IEC 61000-4-12

Electromagnetic Compatibility (EMC) - Part 4-12: Testing and measurement techniques - Ring wave immunity test

IEC 61000-4-16

Electromagnetic compatibility (EMC) - Part 4-16: Testing and measurement techniques - Test for immunity to conducted, common mode disturbances in the frequency range 0 Hz to 150 kHz

IEC 61000-4-18

Electromagnetic compatibility (EMC) - Part 4-18: Testing and measurement techniques - Damped oscillatory wave immunity test

IEC 61000-4-19

Electromagnetic compatibility (EMC) - Part 4-19: Testing and measurement techniques - Test for immunity to conducted, differential mode disturbances and signalling in the frequency range 2 kHz to 150 kHz at a.c. power ports

IEC 61000-4-29

Electromagnetic compatibility (EMC) - Part 4-29: Testing and measurement techniques - Voltage dips, short interruptions and voltage variations on d.c. input power port immunity tests

IEC 61000-4-34

Electromagnetic compatibility (EMC) - Part 4-34: Testing and measurement techniques - Voltage dips, short interruptions and voltage variations immunity tests for equipment with mains current more than 16 A per phase
Combination wave generator 12kV, 6kA.
MIG1206

Surge Generator according to IEC 61180-2. CWG 18kV, 9kA
MIG1809-1P

IN PERFECT HARMONY - Signalling INTEREFERENCE in VOLTAGE & CURRENT Circuits
IMU SLAVE SMART I1V1

1-Phase measuring system for Harmonics & Flicker
HAR1000-1P

Automatic 3-Phase CDN up to 32A / 8kV for EFT, Surge and Ringwave (690V)
IMU-MGE

Surge Generator CWG 12kV / 6kA, 2 Ohm with automatic 3-Phase CDN
MIG1206-3P

Surge Generator CWG 12kV / 6kA, 2 Ohm with automatic 1-Phase CDN
MIG1206-1P

Modular conducted immunity generator up to 5KV EFT/Burst, 5.1KV SURGE
IMU-MGS

Do not disturb - Electronic measuring equipment in energy distribution networks
DOW-CG1

Handheld ESD Simulator with modular discharge circuits up to 30kV
ESD3000

Extension for common mode short duration tests according IEC 61000-4-16
EXT-IMU C-SHORT

3-Phase extension to HAR1000-1P for Harmonics & Flicker
HAR-EXT1000

50 Ohm EFT termination with HV BNC connectors
VERI50 EFT

Discharge Network up to 30kV according ISO TR 10605. 150pF, 330 Ohm
ESD3000DN1

Differential voltage probe for impulses up to 7kV
V-PROBE-SI

External Red and Green warning lamps
WARNING-LAMP

Test cabinet to test explosive devices. With interlock safety switch and warning lamps
TC-ST-ED

Damping circuit to CDN for DC-DC converter testing
DC-DC125

Test coil 1m x 1m for magnetic field test according to IEC 61000-4-8 only for short duration 3s 1000A/m.
MF1000-3

External 16A Variac for Dips and Variations
VAR-EXT1000

Coupling and Decoupling Network (CDN) for injecting disturbance signals
CN16T

Voltage probe for impulses up to 4kV
V-PROBE-PHV

Damping circuit to CDN for DC-DC converter testing
DC-DC63

Test coil 1m x 2.6m for magnetic field test according -8 / -9 / -10
MF1000-2

Coupling network for common mode coupling dc, 50/60Hz and sinusoidal up to 150kHz
CN16

SRC32-18UH
Testing according to IEC 61000-4-11 and IEC 61000-4-34 with maximum EUT current 32A. Used together with the PFS32 to perform dips testing.
SRC32-18UH

Damping circuit to CDN for DC-DC converter testing
DC-DC32

External emergency stop switch
EMERGENCY-STOP

MF1000-1 Inductive coil 1 x 1 m
MF1000-1

Test cabinet made of acrylic glass, With interlock safety switch and warning lamps for MIG generators
TC-ST

3-Phase Interrupt Tester Type up to 32A/480V AC/DC
PFS32

2 Ohm ESD Target with SMA connector & target attenuator cable chain for up to 30kV
ESD-TARGET2 DN

Single phase DIP transformer 230V/16A 50/60Hz. According to IEC 61000-4-11
SRC16-1P

Extends IMU for dc interrupt testing. DC power fail simulator for Imax 125Adc. Vmax 600Vdc. Output floating DC+, DC- and ground
PFS125DC

3000W Single phase Power Source with pre-programmed voltage & frequency combinations
PS3 - Power Source

Damping circuit to CDN for DC-DC converter testing
DC-DC200

1kOhm EFT termination with HV BNC and
VERI1K EFT

Balanced / unbalanced transmission line transformer for EFT and 1MHz Damped Sine
CN-BALUN-AC

10/50 Ohm CDN calibration balun
VERI10-50

CDN for 1.2/50, Ringwave and 10/700 SURGE coupling up to 6kV on up to 4 pair (8 wires)
CDN-UTP8 ED3

CDN for 1.2/50, Ringwave and 10/700 SURGE coupling up to 6kV on up to 4 pair (8 wires)

CDN for oscillatory wave testing of high speed data lines
CDN-DOW-DATA-HF18

CDN for oscillatory wave testing of high speed data lines

EFT, Surge & Ring wave automatic 3-phase CDN for power supply lines. EUT max 690Vac / 1500Vdc / 200A per phase
CDN-A-6-200

EFT, Surge & Ring wave automatic 3-phase CDN for power supply lines. EUT max 690Vac / 1500Vdc / 200A per phase

Automatic 3-Phase CDN up to 32A / 8kV for EFT, Surge and Ringwave (690V)
CDN-M-8-32

Automatic 3-Phase CDN up to 32A / 8kV for EFT, Surge and Ringwave (690V)

EFT, Surge & Ring wave automatic 3-phase CDN for power supply lines. EUT max 690Vac / 1500Vdc / 63A per phase
CDN-A-6-63

EFT, Surge & Ring wave automatic 3-phase CDN for power supply lines. EUT max 690Vac / 1500Vdc / 63A per phase

EFT, Surge & Ring wave automatic 3-phase CDN for power supply lines. EUT max 690Vac / 1500Vdc / 125A per phase
CDN-A-8-125

EFT, Surge & Ring wave automatic 3-phase CDN for power supply lines. EUT max 690Vac / 1500Vdc / 125A per phase

Surge & Ringwave testing on up to 4 asymmetrical data lines
CDN-DATA-4L

Surge & Ringwave testing on up to 4 asymmetrical data lines

Coupling network for common mode coupling dc, 50/60Hz and sinusoidal up to 150kHz 8 lines
CN16-8L

Coupling network for common mode coupling dc, 50/60Hz and sinusoidal up to 150kHz 8 lines

EFT, Surge & Ring wave automatic 3-phase CDN for power supply lines. EUT max 690Vac / 1500Vdc / 200A per phase
CDN-A-8-200

EFT, Surge & Ring wave automatic 3-phase CDN for power supply lines. EUT max 690Vac / 1500Vdc / 200A per phase

EFT, Surge & Ring wave automatic 3-phase CDN for power supply lines. EUT max 690Vac / 1500Vdc / 63A per phase
CDN-A-8-63

EFT, Surge & Ring wave automatic 3-phase CDN for power supply lines. EUT max 690Vac / 1500Vdc / 63A per phase

Mains de-coupling transformer single phase up to 16A for IEC 61000-4-16 common mode testing.
DN16-1P16

Mains de-coupling transformer single phase up to 16A for IEC 61000-4-16 common mode testing.

CDN for oscillatory wave testing of data lines
CDN-DOW-DATA-LF

CDN for oscillatory wave testing of data lines

Coupling network for common mode coupling dc up to 300V
CN16DC

Coupling network for common mode coupling dc up to 300V

DC Line CDN for 8 Lines (4 Pairs).
CN16T8

DC Line CDN for 8 Lines (4 Pairs).

Single phase ANSI coupling network
CN-IMU-ANSI

Single phase ANSI coupling network

CDN for 1.2/50, Ringwave and 10/700 surge coupling 6kV to 2 pair (4 wires) balanced communication lines
CDN-UTP ED3

CDN for 1.2/50, Ringwave and 10/700 surge coupling 6kV to 2 pair (4 wires) balanced communication lines

EFT, Surge & Ring wave automatic 3-phase CDN for power supply lines. EUT max 690Vac / 1500Vdc / 32A per phase
CDN-A-8-32

EFT, Surge & Ring wave automatic 3-phase CDN for power supply lines. EUT max 690Vac / 1500Vdc / 32A per phase

Surge & Ringwave testing on up to 8 asymmetrical data lines
CDN-DATA-8L

Surge & Ringwave testing on up to 8 asymmetrical data lines

EFT, Surge & Ring wave automatic 3-phase CDN for power supply lines. EUT max 690Vac / 1500Vdc / 125A per phase
CDN-A-6-125

EFT, Surge & Ring wave automatic 3-phase CDN for power supply lines. EUT max 690Vac / 1500Vdc / 125A per phase

Three Phase CDN up to 6kV - Manually Operated for EFT, SURGE, RING WAVE Coupling
CDN-F-125

Three Phase CDN up to 6kV - Manually Operated for EFT, SURGE, RING WAVE Coupling

SURGE coupling-decoupling network for data lines IEC 61000-4-5 ED3
CDN-KIT1000 ED3

SURGE coupling-decoupling network for data lines IEC 61000-4-5 ED3

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