EN 61000-6-4, “Electromagnetic compatibility (EMC) – Part 6-4: Generic standards – Emission standard for industrial environments”, limits the electromagnetic noise that equipment without a dedicated EMC standard may emit in factories and similar locations. It is the emission standard most often used for industrial equipment in EMC testing; its immunity counterpart is EN 61000-6-2.
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What is this standard for?
At industrial sites radio receivers are not right next to the equipment, and because the site is fed from its own transformer, noise flowing into the mains is attenuated before it reaches neighbouring homes. The limits are therefore about 10 dB more relaxed than in the residential environment. EN 61000-6-4 gives the radiated and conducted emission limits for equipment without a product standard in this environment; the aim is again to protect radio services.
The standard defines the “industrial location” in the same way as EN 61000-6-2: a separate network fed from its own medium- or high-voltage transformer. It does not apply to equipment within the scope of EN 61000-6-3.
EN 61000-6-4 at a glance
| Current edition | EN IEC 61000-6-4:2019 (IEC 61000-6-4:2018); replaces EN 61000-6-4:2007 and A1:2011 |
|---|---|
| Official title | Electromagnetic compatibility (EMC) – Part 6-4: Generic standards – Emission standard for industrial environments |
| Type of standard | Generic emission standard: gives the limits itself and refers to the CISPR 16 series and CISPR 32 for the measurement method |
| Legislation | EMC Directive 2014/30/EU; where no product standard exists, the presumption of conformity is obtained with this standard |
Which products does it apply to?
All electrical and electronic equipment without a dedicated EMC emission standard that is used indoors or outdoors at industrial locations; emission requirements from 9 kHz to 400 GHz are covered, and no measurement is needed at frequencies where no limit is given.
- Typical examples: machine control cabinets, custom automation boards, industrial power supplies, sensor and actuator units, process measuring instruments, industrial gateways.
- Machinery manufacturers use this standard together with EN 61000-6-2 for the electrical equipment of the machine.
- Equipment with a product standard, such as drives (EN 61800-3) or industrial and scientific equipment (EN 55011), uses that standard.
Measurements per port
- Enclosure port, radiated emission: from 30 MHz to 1 GHz on an open area test site (OATS) or in a semi-anechoic chamber (SAC) at 10 m with a quasi-peak detector; above 1 GHz at 3 m with peak and average detectors. For table-top equipment the fully anechoic room (FAR) option is also available.
- Highest frequency to measure: depends on the highest internal frequency of the equipment: 1 GHz for up to 108 MHz, 2 GHz for up to 500 MHz, 5 GHz for up to 1 GHz, and above that five times the internal frequency up to 6 GHz. If the internal frequency is unknown, the measurement extends to 6 GHz.
- AC mains port, conducted emission: from 0.15 to 30 MHz through a 50 Ω / 50 µH artificial mains network (AMN) with quasi-peak and average detectors; for equipment producing 5 to 30 clicks per minute the limit is relaxed under the CISPR 14-1 rule.
- Wired network port: the common-mode noise on connections such as Ethernet is measured as voltage and current with the CISPR 32 method through a 150 Ω asymmetric artificial network (AAN).
- DC power port: the standard provides an informative annex; whether a measurement is needed depends on how the equipment connects to a DC network.
Limits
| Port and measurement | Frequency | Limit |
|---|---|---|
| Radiated, 10 m, quasi-peak | 30 – 230 MHz | 40 dBµV/m |
| Radiated, 10 m, quasi-peak | 230 – 1000 MHz | 47 dBµV/m |
| Radiated, 3 m, peak / average | 1 – 3 GHz | 76 / 56 dBµV/m |
| Radiated, 3 m, peak / average | 3 – 6 GHz | 80 / 60 dBµV/m |
| Conducted, AC mains, quasi-peak / average | 0.15 – 0.5 MHz | 79 / 66 dBµV |
| Conducted, AC mains, quasi-peak / average | 0.5 – 30 MHz | 73 / 60 dBµV |
| Wired network port, voltage, quasi-peak / average | 0.15 – 0.5 MHz | 97 to 87 / 84 to 74 dBµV (decreasing with frequency) |
| Wired network port, voltage, quasi-peak / average | 0.5 – 30 MHz | 87 / 74 dBµV |
Radiated measurements may also be made at 3 m, 5 m or 30 m, with the limit corrected for the distance.
How is compliance assessed?
- The measured value must stay below the limit at the frequency concerned; the result is pass or fail.
- The equipment is measured in the operating mode producing the highest emission and with the typical installation defined by the manufacturer; cable lengths and screening are recorded in the report.
- Measurement uncertainty is taken into account according to CISPR 16-4-2.
Place in the CE marking process
- It is checked whether a dedicated EMC product standard exists; if not, and the equipment is for industrial use, EN 61000-6-4 is chosen.
- The highest internal frequency and the ports of the equipment are determined; a measurement plan is made.
- The measurements are carried out in an accredited laboratory; the report records the operating mode, the installation and the measurement distance.
- The report goes into the technical file; the EU Declaration of Conformity under the EMC Directive is drawn up and the product is CE marked.
Standards applied together
- EN 61000-6-2: generic immunity standard for the same environment
- EN 61000-6-3: generic emission for residential environments
- EN 55011: radio-frequency disturbance of industrial, scientific and medical equipment
- EN 61000-3-12 and EN 61000-3-11: harmonics and flicker for equipment above 16 A
Frequently asked questions
Are residential limits required for industrial equipment?
If the equipment will be used only at industrial sites, the EN 61000-6-4 limits are sufficient. If the same equipment is also sold into offices or workshops fed from the public network, the stricter EN 61000-6-3 limits are chosen; the manual states which environment the equipment is designed for.
When is the wired network port measured?
Whenever the equipment has a network port, such as Ethernet, that connects to the outside through a long cable. The measurement is made through an asymmetric artificial network that represents the common-mode noise of the port with a 150 Ω impedance; the method and setup are taken from CISPR 32.
What if my product exceeds the limits?
For conducted emission, the input filter and the earthing arrangement; for radiated emission, slower switching, cable screening and cable routing inside the cabinet are the typical solutions. In cabinet systems, choosing screened drive output cables alone solves most problems.
Other standards in this group
- EN 61000-6-2: Generic Immunity for Industrial Environments
- EN 61000-6-3: Generic Emission for Residential and Light-Industrial Environments
- EN 61000-6-1: Generic Immunity for Residential and Light-Industrial Environments
