EMI/EMC Testing

Electromagnetic compatibility (EMC) is the ability of electrical equipment and systems to function acceptably in their electromagnetic environment, by limiting the unintentional generation, propagation and reception of electromagnetic energy which may cause unwanted effects such as electromagnetic interference (EMI) or even physical damage in operational equipment. The goal of EMC is the correct operation of different equipment in a common electromagnetic environment. EMC testing has been divided into two parts as detailed below:

Immunity testing – measures how a device will react when exposed to electromagnetic noise and other disturbances. The purpose of these tests is to gain a reasonable assurance that the device will operate as intended when used within its expected operating environment.

Emissions testing – measures the amount of electromagnetic noise generated by a device during normal operation. The purpose of these tests is to ensure that any emission from the device are below the relevant limits defined for that type of device. This, in turn, provides a reasonable assurance that the device will not cause harmful interference to other devices operating within its expected operating environment.

The common EMC testing standards are as follows:

• IEC 61326-1 – Electrical equipment for measurement, control and laboratory use – EMC requirements – Part 1: General requirements
• IEC 61000-3-2 – Electromagnetic compatibility (EMC) – Part 3-2: Limits – Limits for harmonic current emissions (equipment input current ≤ 16 A per phase)
• IEC 61000-3-3 – Electromagnetic compatibility (EMC) – Part 3-3: Limits – Limitation of voltage changes, voltage fluctuations and flicker in public low-voltage supply systems, for equipment with rated current <= 16 A per phase and not subject to conditional connection
• IEC 61000-3-11 – Electromagnetic compatibility (EMC) – Part 3- 11: Limits – Limitation of voltage changes, voltage fluctuations and flicker in public low- voltage supply systems — Equipment with rated current <= 75 A and subject to conditional connection
• IEC 61000-3-12 – Electromagnetic compatibility (EMC) – Part 3- 12: Limits – Limits for harmonic currents produced by equipment connected to public low-voltage systems with input current > 16 A and <= 75 A per phase
• IEC 61000-6-1 – Electromagnetic compatibility (EMC) – Part 6-1: Generic standards – Immunity for residential, commercial and light-industrial environments I
• IEC 61000-6-2 – Electromagnetic compatibility (EMC) – Part 6-2: Generic standards – Immunity for industrial environments
• IEC 61000-6-3 – Electromagnetic compatibility (EMC) – Part 6-3: Generic standards – Emission standard for residential, commercial and light-industrial environments

IEC 61000-6-4 – Electromagnetic compatibility (EMC) – Part 6-4: Generic standards – Emission standard for industrial environments

IEC 61000-6-5 – Electromagnetic compatibility (EMC) – Part 6-5: Generic standards – Immunity for equipment used in power station and substation environment

IEC 61000-4-2 – Electromagnetic compatibility (EMC) – Part 4-2: Generic standards – Testing and measurement techniques – Electrostatic discharge immunity test

IEC 61000-4-4 – Electromagnetic compatibility (EMC) – Part 4-4: Generic standards – Testing and measurement techniques – Electrical fast transient/burst immunity test

IEC 61000-4-5 – Electromagnetic compatibility (EMC) – Part 4-5: Generic standards – Testing and measurement techniques – Surge immunity test