Appliance classes
electrical appliance manufacturing industry protection classes
Appliance classes (also known as protection classes) specify measures to prevent dangerous contact voltages on unenergized parts, such as the metallic casing or chassis, of an electronic device. In the electrical appliance manufacturing industry, the following appliance classes are defined in IEC 61140 and used to differentiate between the protective-earth connection requirements of devices.
Class 0
These appliances have no protective-earth connection and feature only a single level of insulation between live parts and exposed metalwork. If permitted at all, Class 0 items are intended for use in dry areas only. A single fault could cause an electric shock or other dangerous occurrence, without triggering the automatic operation of any fuse or circuit breaker. Sales of such items have been prohibited in much of the world for safety reasons, for example in the UK by Section 8 of The Low Voltage Electrical Equipment (Safety) Regulations 1989 and New Zealand by the Electricity Act. A typical example of a Class 0 appliance is the old style of Christmas fairy lights. However, equipment of this class is common in some 120 V countries, and in much of the 230 V developing world, whether permitted officially or not. These appliances do not have their chassis connected to electrical earth. In many countries the plug of a Class 0 equipment is such that it cannot be inserted to grounded outlet like Schuko.
Begin with the source’s own compact description: “Appliance classes” is electrical appliance manufacturing industry protection classes. The dossier treats that line as a proposition to test through Appliance, classes and electrical, not as a finished interpretation.
Why this record matters
The phrase “electrical appliance manufacturing industry protection classes” supplies a clear boundary for inquiry. It also exposes the unanswered questions: who defined that boundary, when it became stable and which sources sit outside it.
The citation trail is more important than the brevity of the summary: it shows where individual claims can be examined in context. The source revision retrieved here is dated May 26, 2026. The linked authority identifier is Q1877948. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1989.
The absence of detail may reflect summary conventions rather than a lack of surviving documentation. The source lead contains qualifying language; that uncertainty should survive quotation, summary and reuse. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.
- Subject orientation
- Search vocabulary
- Locating named sources
The closest primary source, responsible institution and strongest cited specialist reference.
Three-step research path
- Establish the record: confirm the title “Appliance classes”, its source revision and the description used here.
- Expand the search: follow Appliance classes primary sources, Appliance classes archive and Appliance research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Appliance classes”?
- Which institution is responsible for the underlying evidence?
- Which cited source is closest to the event, object or claim?
Search terms from this dossier
This entry incorporates text from “Appliance classes” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.