CE marking of transformers: which directives apply and what the declaration must contain

The CE mark on a transformer nameplate is the manufacturer's statement that the product meets every applicable EU rule. For a distribution transformer that is a specific and short list – and each item is verifiable. Here is what should be behind the mark.

The applicable EU acts

Act	What it requires for a transformer	Harmonised standard
Low Voltage Directive 2014/35/EU	Safety of the LV side (up to 1 000 V AC): insulation, clearances, terminals, earthing	EN IEC 60076 series, EN 50588-1
EMC Directive 2014/30/EU	Transformers are passive; a statement of inherently benign EMC behaviour is normally sufficient	—
RoHS Directive 2011/65/EU	No restricted substances (lead, cadmium, mercury, hexavalent chromium…) above thresholds	EN IEC 63000
Ecodesign Regulation (EU) 2019/1783	Maximum no-load and load losses (Tier 2 since 1 July 2021); required information on nameplate and documentation	EN 50708 series

The Machinery Regulation, the Pressure Equipment Directive and the ATEX Directive do not apply to standard distribution transformers.

What the EU declaration of conformity must contain

1. Product identification: type, serial number, rated power and voltages.
2. Name and address of the manufacturer (and of the importer, if the manufacturer is outside the EU).
3. The statement that the declaration is issued under the sole responsibility of the manufacturer.
4. The list of EU acts – as above – and the harmonised standards applied, with their dates.
5. For Ecodesign: the reference to Regulation (EU) 2019/1783 and the declared P0 and Pk.
6. Place, date, name and signature of the authorised person.

The declaration must be in a language accepted by the country of installation; English is accepted in most EU states, but Poland, Germany, France and Italy may require a translation for public tenders.

Red flags

• A "CE certificate" issued by a test laboratory. There is no such thing – CE is a self-declaration; laboratories issue test reports, not CE certificates.
• A declaration without serial numbers or with a generic product description.
• Losses on the nameplate that exceed the Tier 2 table – the transformer cannot legally be placed on the EU market.
• No Ecodesign reference at all on a unit delivered after July 2021.
• A manufacturer address outside the EU and no named EU importer.

How Keynetgrid documents conformity

Every PNACHO transformer is delivered with an EU declaration of conformity covering the LVD, EMC, RoHS and Ecodesign requirements, referencing EN IEC 60076, EN 50588-1 and EN 50708, together with the routine test report that proves the declared losses for that serial number. The documents are in English; Polish and German versions are available on request. Details are in the "Documents" section of every product page in the oil-immersed and cast-resin ranges.