Sealing expert sheet - MARECHAL ELECTRIC

IP: the ultimate in sealing protection?

Every application has characteristics that can affect the safety or correct operation of an electrical appliance. Known in good engineering practice as ‘external influences’, they fall into one of three categories: construction, application, or environment.

Prior knowledge of external influences is essential when selecting the equipment to be installed.
The IEC/EN 60529 standard “Degrees of protection provided by enclosures (IP Index)” defines the test conditions, procedures and penalties for qualifying impermeability.

IP Index

The presence of water is a widespread external environmental influence. The watertightness level is determined by the second digit of the IP Index.
In addition, installation standards (e.g. NF C 15-100 in France) recommend a minimum IP level for each application. The aim of the standard is to establish ‘template’ environments to which the appliances are most likely to be subjected during transport, storage, installation and use.
To address concerns on site, the standard may introduce new IP indexes (IPX9 was added in 2013).

Although widely used, the standards-based approach has its limitations:

The templates are fixed and do not correspond to any reality (the standard considers fresh water, fixes a temperature and a duration of exposure, details immutable means/processes…)
Some very real problems are not taken into account – they are not covered by the standard. This is the case of water run-off, which the standard does not take into account

Finally, all elements contributing to sealing must be checked and maintained. MARECHAL ELECTRIC provides its customers with:

Specific instructions for checking and maintaining tightness
Spare parts to maintain the tightness in the long term

Key points to remember

The IP Index is a simple tool that allows manufacturers and users to:

Know how sealed a piece of equipment is according to known
and globally accepted environmental templates
Compare sealing levels between different products.

The external influences encountered in the field are infinite:

It is therefore impossible for standards to define a single template covering all applications.

The IP Index is a reference, but does not constitute absolute impermeability in real-life conditions.

Additional letter (optional)

This letter indicates the degree of protection of persons against access to dangerous parts.
In principle, the additional letter is only used if the actual protection against access to dangerous parts is higher than that indicated by the first characteristic numeral (which indicates the degree of protection of the appliance against harmful ingress of solid foreign matter).