Power cables, carrying mains electricity, are regulated by national standards and independent test houses. This promotes quality and safety for the end user. The same or other standards may also apply to the equipment being powered by the plug or cable.
The approvals process has three broad categories:
- The national standards body or agency that issues and updates a standard. This includes dimensions, materials required, strength requirements, voltage and current minima etc. In the UK, this is British Standards, in the USA the American National Standards Institution, in Germany DIN.
- The testing agency or certification agency. This may be the same as the national standards agency, or a third party. They test the product to be approved and compare it to the standard. If the product meets the requirements they issue an approval certificate. In the UK this could be BS, ASTA, or any European test house; in the USA UL or ETL; in Germany VDE or TUV.
- Periodic and random inspections. The manufacturing facility and product are inspected prior to renewal of the approval certificate. There may also be surprise inspections of the factory, and random inspections of the finished product actually on the market.
Testing covers over 300 different points, and varies by standard. Some examples from the UK BS1363: dimensions of the plug, dimensions of pins, distances between pins and edge of plug, thickness of insulation, presence (or not) of partially insulated pins, inaccessibility of live parts, materials used and smoothing of edges are checked.
Physical tests include twisting pins, 36N force on the plug, 1,100N force on the pins, being dropped 5,000 times, flexing the cable 10,000 times, pulling the cable, checking for creepage, and leaving for one week at 70°C. Voltage and over voltage is tested, along with temperature rise at the maximum rated current. Testing is comprehensive and takes several weeks.
There are many benefits of product approval. Specific approvals may be required to supply certain markets, e.g. medical, government or military users. Approvals certificates are often required by customs when a product is imported into a country, and having them ready prevents delays or even rejection at the border. Having international approvals potentially increases the target market to new countries. Depending on the product, approval may be required full stop: import or sale is illegal without it. Another benefit is in the marketing of the product: sales may increase if the product is advertised as “approved by British standards”. The approval may be valid for more than one country: for example, approval in one EU country is recognised in all other EU countries (the CB scheme); Australia and New Zealand recognise each other’s approvals. Feedback from the approvals process may improve the product quality, and is an important factor in the event of claims.
There are negatives also. The major disadvantage is cost: certification may cost thousands or tens of thousands. The process can be time consuming with bureaucracy and repeat visits: “everyone fails their first inspection”. The inspection can be difficult, e.g. the inspector finding minor points, e.g. the flammability of the glue used on a warning label, or finding unrelated non-conforming products in the same manufacturing environment, e.g. UK plugs kept in the same room as USA cable. The standard may be open to interpretation, with no two inspectors requiring the same things; any required changes may be expensive to implement. Also, the certificate may not be recognised in all states, so the process may have to be repeated for slightly different standards.
Depending upon the positives and negatives, there are generally three levels of product approval:
- Approved. The product has the correct and in date approval certificate. The ideal situation.
- Conforms. The product meets the safety standard, but has a manufacturer declaration, CE marking, or different approvals mark. Alternatively the manufacturer may have ceased trading or let an approval lapse. Acceptability depends on the situation.
- Unapproved. This may where no standards exist, e.g. supplying the third world and/or an obsolete product no longer covered by any standard. Another example is manufacturer-proprietary connectors only found on that brand, e.g. only fits on a certain brand of vacuum cleaner, electric mower etc. Rare, and not recommended.
It should be noted that the CE mark, EAC mark and G mark are not issued by independent approvals bodies, but are instead based upon manufacturer or importer self-declarations. Full approvals are preferred wherever possible.
Underpinned by our market leading technical knowledge and long standing relationships with manufacturers, our in house quality procedures ensure the correct approved part for the application is specified, manufactured, inspected and delivered.
All Morvan Trading products are covered by at least one approval or declaration of conformity unless specified – please contact us if in doubt. We aim to make the certification process and exporting as easy as possible for our customers. Approval certificates are stored and backed up electronically and can be emailed on request. However, we do not guarantee to keep all approvals certificates indefinitely, so we strongly recommend keeping copies locally.