1. Units and apparatus for application in areas with potentially explosive atmosphere

The owner of equipment or an apparatus to be used in areas with a potentially explosive atmosphere is required to assess whether explosive atmospheric conditions exist, and determine the probability of the risk (EC directive 99/92/EC). Then the owner needs to classify the respective facilities into zones.

On the other hand, the manufacturers of "explosion-protected" equipment and components are required to classify these into categories. These categories mirror the requirements for the different zones. Equipment in a certain category is suitable/required for use in the corresponding zone.

An explosive atmosphere is a mixture with air of flammable gases, vapours, mists or dusts. To address different ignition sources and the required protective measures, differing zones have been defined for gases (including vapours, mists) and dust. The following table lists the different zones and the corresponding ATEX equipment categories:

EN 1127-1 defines various zones, in which a hazardous amount of potentially explosive atmosphere may exist or develop.

The standard EN 14986 for the mechanical section of the blower allows application of Elektror's products also in areas with potentially explosive atmosphere. This standard has replaced the VDMA guidelines 24169 - Part 1 and 2, which are no longer valid since 07-01-2003 and were valid only in Germany until that date.

If the explosive atmosphere consists of a mixture with air of flammable or ignitable gases, mists or vapours, one of the following zone definitions may apply:

If the explosive atmosphere consists of a mixture with air of flammable or ignitable dusts, one of the following zone definitions may apply:

Elektror does not offer devices for zone 0/20.
This information refers to equipment for group II, that is, equipment that is not suitable for operation under firedamp or mining conditions.

2. Temperature classes

Flammable gases, vapours and mists are classified by their ignition temperatures. Be sure to take note of this when using equipment in areas with potentially explosive mixtures.

The temperature classes explain the highest admissible surface temperature for the equipment.

The Elektror standard is to supply all of its products for temperature class T3. Applications for temperature class T4 are possible in some cases upon special request.

Glow temperatures:

The glow temperature of a dust deposit is the lowest temperature of a heated surface that will cause ignition of a dust layer of 5 mm resting on it.

The owner of a device or equipment is required to determine in writing the ignition or glow temperatures in his explosion protection document.

Type of ignition protection e: Increased safety (see EN 50019)

To achieve this type of ignition protection the manufacturer has taken measures, which prevent with an increased degree of safety unacceptably high temperatures and sparks or electrical arcs on the internal or the external parts of electrical equipment whose normal operation does not involve high temperature, sparks or arcs.

Type of ignition protection d: Flameproof Enclosure (see EN 50018)

To achieve this type of ignition protection, those parts of electrical equipment which could ignite an explosive atmosphere are located inside an enclosure which can withstand the pressure of an explosion of the explosive mixture inside, and which prevents the transmission of the explosion to the explosive atmosphere surrounding the enclosure.

The equipment group II for type of ignition protection "d" or "de" is further subdivided into the ignition sub-groups IIA, IIB, and IIC (see EN 50018 for flameproof enclosure).

For equipment with drives that are suitable exclusively for operation in conjunction with a frequency converter only type ?d? ignition protection is admissible.

As standard, Elektror supplies products with type "e" ignition protection. Applications for type "d" explosion protection are possible in some cases upon special request.

3.  Standards and directives

An equipment owner or system manufacturer may use the following list of ATEX-related standards and directives to gather guidelines for performance of a risk analysis or for definition of zones. We do not claim that the information provided is complete.
European regulations (converted into national laws):

Directive 92/95/EEC General product safety

Directive 99/92/EC Explosion protection directive for employers

Directive 98/37/EC Machinery directive

Directive 94/9/EC Explosion protection directive (ATEX 95)

www.europa.eu.int

www.mybeuth.de

Standards, except only:
Standards are subject to change. The following listing is published for information purposes only and possiblly does not represent the current status. Claims cannot be based on this listing.

DIN EN 1127-1  Explosion prevention and protection, basic concepts and methology

DIN EN 13 463-1  Non-electrical equipment for potentially explosive atmospheres

EN 14 986 Design of fans working in potentially explosive atmospheres

DIN EN 60 079-14 Electrical apparatus for explosive gas atmospheres

DIN EN 61 241-14 Electrical apparatus for use in the presence of combustible dust

www.mybeuth.de

4.  Application aids and organisations

The following is a list of general application aids as well as a list of organisations to which our customers and inquierer may turn for more information.

Application aids:

Die Betriebssicherheitsverordnung - eine Umsetzungshilfe
(aid for application of the operational safety regulations - applicable Germany only)                       

Published by:

Staatliches Amt für Arbeitsschutz Essen
(State council for occupational safety, Essen, Germany)
Ruhrallee 55, 45138 Essen, www.stafa-essen.nrw.de

Zentrum für Umwelt und Energie der Handwerkskammer Düsseldorf
(Centre for environmental and energy of the chamber of commerce, Düsseldorf, Germany)
Mülheimer Str. 6, 46049 Oberhausen, www.hwk-duesseldorf.de/uzh

Niederrheinische Industrie- und Handelskammer Duisburg
(Chamber of industry and commerce for the lower Rhine area, Duisburg, Germany)
Mercatorstr. 22-24, 47051 Duisburg, www.ihk-niederrhein.de

5. ATEX units by ELEKTROR

Notes:
This listing reflects the current state of developments by Elektror. Units for zone 1/21 (categroy 2G/2D) are under way.
The above mentioned units may also be operated when they are permanently connected to a system on the intake and the pressure end (installation type D). In such cases, however, the same zone definition must apply inside and outside the unit! In addition to the sources and links listed above our Customer Support is pleased to answer your queries, contact us via  atex@elektror.de.