Electrical safety – LVD

From the webstore of the International Electrotechnical Commission (IEC), you can check the latest version of the IEC standard. The site also contains a “preview” button with which you can view the scope and table of contents of the standard free of charge. With the name of the standard and the scope, you can roughly assess whether it is suitable for your appliance (for example, if your product is a ceiling light, and the standard is for toasters).

You can find the latest versions of the standards applicable in Europe from the website of the European Electrotechnical Committee for Standardization (CENELEC). You can search under “standard reference” if you know the standard number.

The EU declaration of conformity may refer to harmonised EN standards published in the Official Journal of the European Union. The Commission’s website contains a list of standards harmonised under the LVD (e.g. “summary list as PDF” at the bottom of the page). The two main points on the list are:

• Column 5: “date of start of presumption of conformity (1)” indicates the starting date since the standard could be referred to in the declaration of conformity.
• Column 10: “Date of withdrawal from OJ end of presumption of conformity (6)” shows the last date on which this version of the standard may be referred to in the EU declaration of conformity.

The use of standards is not mandatory but is often the easiest way to verify the conformity of a product.

After the publication of a new EN standard or an amendment supplementing or replacing it, there will normally be a transitional period of about three years, after which the new standard will have to be referred to in the EU declaration of conformity (provided that the standard is also published in the list of harmonised standards).

When examining the EU declaration of conformity and test reports, it is important to note that this is the latest version of the standard, and that the amendments to the standard are included. The amendments may include stricter testing requirements:

• For example, EN 60335-1:2012+A1:2019, amendment A1 of 2019 introduces a stricter 100 N requirement for the pull test of cord anchorage in appliances to be installed.

On the other hand, a larger technical change in the standard will often lead to the publication of a completely new version of the standard.

You can buy Finnish SFS standards for the electrical field and SFS-EN standards from the website of the Finnish Standards Association SFS. The majority (approximately 95%) of Finnish electricity standards are identical to the EN standards. More information on standards and standardisation is also available on the website of the National Electrotechnical Standardisation Organisation SESKO.

Regarding electrical safety, an important part of the conformity assessment is testing the electrical safety of the appliances. For testing purposes, it is essential to identify the applicable standards and their possible amendments. The scope is mentioned at the beginning of the standard, which describes which products are covered by the standard.

It is not always clear whether a product falls within the scope of a certain standard. In matters requiring interpretation, you can ask for help from standardisation organisations or accredited testing laboratories.  

The appliance’s electrical safety can be tested by the manufacturer themselves or by an external laboratory. In addition, the importer or distributor of the device can also test the device, or have it tested if they want to ensure its safety. Testing electrical safety often requires knowledge of the standard and laboratory facilities and equipment, so the use of an external laboratory is often recommended. The use of an external accredited laboratory also increases the reliability of testing. 

When selecting a testing laboratory, you should assess the laboratory’s competence to run tests. A national accreditation body (e.g. FINAS in Finland, SVEDAC in Sweden, DAkkS in Germany) can accredit a laboratory to carry out tests in accordance with a certain standard. The accredited laboratory has passed an impartial assessment.

You can check the accredited competence area of a laboratory operating in Finland on the website of the FINAS accreditation service.  You should check at least the following in the laboratory’s certificate of competence:  

• Is the laboratory an accredited testing laboratory (letter T and number such as T004)
• Is the standard used within the scope of the laboratory (such as EN 61010-1)

You can also check the validity of the calibration laboratory on the FINAS website if you need a calibration for an accurate measuring device (such as a production tester). In the calibration laboratory’s certificate of competence, you can check whether the laboratory has the competence to calibrate electrical quantities, weight, temperature, or humidity, for example. The calibration laboratory can be identified by a number sequence starting with the letter K.

Unaccredited testing and calibration are suitable for testing the product development phase, in-house calibration, or finding the right direction towards the final conformity assessment.

In electrical safety testing, the appliance is tested according to a standard suitable for it. Electrical appliances are typically based on the IEC standard, and in addition, the country-specific exceptions that European countries have announced under the same EN standard (such as higher frost resistance in Finland) are checked. Otherwise, the content of the IEC and EN standards for the same standard number is usually very similar. Electrical safety testing can be performed typically:

• Complete type testing: the whole conformity to the standard is tested
• Partial testing: only the essential electrical safety requirements are tested

Complete type testing is always the safer option, but partial testing is well suited for appliances in the product development phase, or when you want to ensure that the appliance has no clear safety deficiencies.  In electrical safety testing, the following are typically examined at least:

• Markings and instructions
  • Data plate, warnings, user instructions
• Mechanical structure of the appliance
  • IP rating, enclosure strength, sharp edges, etc.
• Fire resistance of materials (such as enclosure)
  • Filament test, flame test, use of certified material
• Electrical isolation and separation
  • Voltage strength test (between primary and secondary, primary and enclosure)
  • Clearances and creepage distances(such as sufficient separation in the transformer)
• Failure tests
  • Single fault event (such as a short circuit in a component)
  • Overload
  • Foreseeable misuse
• Components and their dimensions
  • Wiring, earthing, connectors (dimensions, material)
  • Safety components (such as a fuse, fuse dimensions)
  • Critical components (such as a capacity or between phases, transformers, optocoupler)
• Connection to the power grid
  • Plug design, cord anchorage, supply cable dimensions

The specific standards for different appliances also lay down specific requirements so that the appliance can be designed and operated safely (for example, a coffeemaker, sockets, lamps).

You should check the basic information from the testing, or the test report received from the manufacturer – for example, which device the report concerns, and whether the model of the device in question can be found in the report. The competence of the testing laboratory can be assessed as described above. In addition, the standard used for testing should be checked. Even if you do not know anything about the device itself or the related standards, you should check the following in the standard:

• Name of the standard
• Scope
• Is the version used for testing the latest version of the standard?